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Associations between food portion sizes, insulin resistance, VO2 max and metabolic syndrome in European adolescents: The HELENA study
Abstract
Background and Aims
This study aims to examine associations of food portion sizes (PS) with markers of insulin resistance (IR) and clustered of metabolic risk score in European adolescents.
Methods
495 adolescents (53.5% females) from the HELENA study were included. The association between PS from food groups and HOMA-IR index, VO2 max, and metabolic risk score was assessed by multilinear regression analysis adjusting for several confounders. ANCOVA was used to determine the mean differences of food PS from food groups by HOMA-IR cut off categories, using maternal education as covariable.
Results
Larger PS from vegetables in both gender, and milk, yoghurt, and milk beverages in males were associated with higher VO2 max, while larger PS from margarines and vegetable oils were associated with lower VO2 max (p< 0.05). Males who consumed larger PS from fish and fish products; meat substitutes, nuts, pulses; cakes, pies, biscuits; and sugar, honey, jams, chocolate have a higher metabolic risk score (p<0.05). Males with lower HOMA-IR cut off values consumed larger PS from vegetables, milk, yoghurt, and milk beverages (p < 0.05). Females with lower HOMA-IR cut off values consumed larger PS from breakfast cereals, while those with higher HOMA-IR cut off values, consumed larger PS from butter and animal fats (p =0.018).
Conclusion
The results show that larger PS from dairy products, cereals, and high energy dense foods are a significant determinant of IR and VO2 max and larger PS from food with higher content of sugar were associated with higher metabolic risk score.
... (a) The distribution of the daily food allotment should be spaced over time to allow for smaller portion sizes of food in each meal as a way to facilitate streamlined digestive processes (and thus their timing) and to prevent substrate overloads. Large portions and a higher frequency of meals both increase the net energy balance [636], and large servings also increase insulin resistance [637], but the effect on total energy intake in a higher number of meals is more limited on these parameters [638]. (b) All meals should contain a varied mix of nutrients for optimal assimilation, but (in humans) the ingestion of carbohydrates (in special digestible starches and sugars taken in large amounts) should be combined with the presence of protein. ...
This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS’s origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this ‘very’ human disease.
... 40 Although most previous research focused on sex as a predictor of risk propensity, in the present study, a multiple regression analysis highlighted a significant indirect effect of other mediating variables (VO 2 max, handgrip strength and age), which explained most of the factors analysed. However, this may be due to biological sex differences during adolescence, which may influence young people's perceptions and behaviours, 72 with significantly higher VO 2 max 76 and handgrip strength values detected in males. More specifically, higher values of VO 2 max, handgrip strength and an older age, were related to higher perceived competence and greater competitiveness. ...
Objectives
To examine the associations of cardiorespiratory fitness (VO 2 max) and muscular strength with indicators related to the risk scale, such as perceived competence, sensation seeking, competitiveness, risk taking and risk perception in sports.
Design
Cross-sectional study.
Setting
High schools from the Region of Murcia (Spain).
Participants
Three-hundred-and-seventeen adolescents participated (mean age: 13.69±1.2 years old).
Primary and secondary outcome measures
Body mass, body height, Course-Navette test, upper limb strength and psychoeducational factors that determine the propensity towards sports accidents in school children, the Sports Accident Propensity Scale were evaluated. It was performance t-test for independent samples, stepwise multiple linear regression models and a multiple mediation analysis.
Results
The analysis showed significant differences with respect to sex in height, VO 2 max, handgrip strength and in all factors of the questionnaire (p=0.02-<0.01). Adolescents who presented greater VO 2 max, strength in the handgrip test and age showed a higher score in factors 1 and 3. Higher scores in factor 2 were associated with better VO 2 max and strength in handgrip test. Youngers and better values of strength in the handgrip showed higher score in factors 4 and 5. The mediation analysis with two mediating variables (handgrip strength and VO 2 max) showed a significant indirect effect. When handgrip strength and VO 2 max were included in the equations, the association between sex and each factor ceased to be significant.
Conclusion
This study highlights the potential benefits of muscular strength (handgrip) and VO 2 max in the perceived risk scale, and the variable of age on this.
Trial registration number
Clinical trial: NCT05544370 (pre-results).
Obesity prevalence has been simultaneously increasing with high consumption of large food portion sizes (PS). However, there is scarce information on PS of energy-dense (ED) foods as a potential risk factor of obesity in adolescents. In the present study, we investigate the association between the PS of the most ED foods and body composition. A sample of 1889 adolescents (54.4% females) from the Healthy Lifestyle in Europe by Nutrition in Adolescence cross-sectional multicenter study (HELENA–CSS) study were included. Most ED foods (e.g., cheese) were selected according to higher fat and/or sugar content and low fiber and water. Linear and ordinal logistic regression models were adjusted for age, physical activity, total energy intake (TEI), and socioeconomic status (SES). Analysis was performed both in those adolescents reporting plausible energy intake according to the approach of Goldberg et al. and in the whole sample. In male plausible reporters, PS from “breakfast cereals” showed a significant and positive association with BMI (β = 0.012; 0.048). PS from “carbonated soft drinks” in males (OR = 1.001; 95% CI 1.000; 1.002) and “bread and rolls” in females (OR = 1.002; 95% CI 1.000; 1.004) were associated with higher probability of having obesity, while “sweet bakery products” were associated with lower probability of having obesity (OR = 0.996; 95% CI 0.991; 0.999) in females. The present study suggests association between PS of ED foods and obesity in European adolescents. Prospective studies are needed to examine the effect of prolonged exposure to large PS and obesity development.
Parallel with the current pediatric obesity epidemic, the escalating rates of youthonset type 2 diabetes mellitus (T2DM) have become a major public health burden. Although lifestyle modification can be the first-line prevention for T2DM in youths, there is a lack of evidence to establish optimal specific exercise strategies for obese youths at high risk for T2DM. The purpose of this narrative review is to summarize the potential impact of exercise on 2 key pathophysiological risk factors for T2DM, insulin sensitivity and β-cell function, among obese youths. The studies cited are grouped by use of metabolic tests, i.e., direct and indirect measures of insulin sensitivity and β-cell function. In general, there are an increasing number of studies that demonstrate positive effects of aerobic exercise, resistance exercise, and the 2 combined on insulin sensitivity. However, a lack of evidence exists for the effect of any exercise modality on β-cell functional improvement. We also suggest a future direction for research into exercise medical prevention of youth-onset T2DM. These suggestions focus on the effects of exercise modalities on emerging biomarkers of T2DM risk.
In the general population, there is a popular belief that a vegan diet may be associated with a lower exercise performance due to the lack of certain nutrients in vegan individuals. Thus, the purpose of the present study was to examine endurance and muscle strength differences between vegan and omnivore participants.
We studied 56 healthy young lean physically active women (age: 25.6 ± 4.1 years; body mass index: 22 ± 1.9 kg/m²). Participants were classified as vegan (n = 28) or omnivore (n = 28) based on their eating habits. All volunteers followed either a vegan or an omnivore diet for at least 2 years. Anthropometric measurements, body composition, estimated maximal oxygen consumption (VO2 max), a submaximal endurance test (70% of VO2 max), muscle strength (leg and chest press), and dietary factors were measured.
Both groups were comparable for physical activity levels, body mass index, percent body fat, lean body mass, and muscle strength. However, vegans had a significantly higher estimated VO2 max (44.5 ± 5.2 vs. 41.6 ± 4.6 ml/kg/min; p = 0.03, respectively) and submaximal endurance time to exhaustion (12.2 ± 5.7 vs. 8.8 ± 3.0 min; p = 0.007, respectively) compared with omnivores.
The results suggest that a vegan diet does not seem to be detrimental to endurance and muscle strength in healthy young lean women. In fact, our study showed that submaximal endurance might be better in vegans compared with omnivores. Therefore, these findings contradict the popular belief of the general population.
The metabolic syndrome (MetS) is a group of cardiovascular risk factors that are associated with insulin resistance and are driven by underlying factors, including visceral obesity, systemic inflammation, and cellular dysfunction. These risks increasingly begin in childhood and adolescence and are associated with a high likelihood of future chronic disease in adulthood. Efforts should be made at both recognition of this metabolic risk, screening for potential associated Type 2 diabetes, and targeting affected individuals for appropriate treatment with an emphasis on lifestyle modification. Effective interventions have been linked to reductions in MetS—and in adults, reductions in the severity of MetS have been linked to reduced diabetes and cardiovascular disease.
Aims:
The PREVIEW lifestyle intervention study (ClinicalTrials.gov Identifier: NCT01777893) is, to date, the largest, multinational study concerning prevention of type-2 diabetes. We hypothesized that the initial, fixed low-energy diet (LED) would induce different metabolic outcomes in men vs women.
Materials and methods:
All participants followed a LED (3.4 MJ/810 kcal/daily) for 8 weeks (Cambridge Weight Plan). Participants were recruited from 8 sites in Europe, Australia and New Zealand. Those eligible for inclusion were overweight (BMI ≥ 25 kg/m2 ) individuals with pre-diabetes according to ADA-criteria. Outcomes of interest included changes in insulin resistance, fat mass (FM), fat-free mass (FFM) and metabolic syndrome Z-score.
Results:
In total, 2224 individuals (1504 women, 720 men) attended the baseline visit and 2020 (90.8%) completed the follow-up visit. Following the LED, weight loss was 16% greater in men than in women (11.8% vs 10.3%, respectively) but improvements in insulin resistance were similar. HOMA-IR decreased by 1.50 ± 0.15 in men and by 1.35 ± 0.15 in women (ns). After adjusting for differences in weight loss, men had larger reductions in metabolic syndrome Z-score, C-peptide, FM and heart rate, while women had larger reductions in HDL cholesterol, FFM, hip circumference and pulse pressure. Following the LED, 35% of participants of both genders had reverted to normo-glycaemia.
Conclusions:
An 8-week LED induced different effects in women than in men. These findings are clinically important and suggest gender-specific changes after weight loss. It is important to investigate whether the greater decreases in FFM, hip circumference and HDL cholesterol in women after rapid weight loss compromise weight loss maintenance and future cardiovascular health.
Obesity and its associated disorders, such as insulin resistance, dyslipidemia, metabolic inflammation, dysbiosis, and non-alcoholic hepatic steatosis, are involved in several molecular and inflammatory mechanisms that alter the metabolism. Food habit changes, such as the quality of fatty acids in the diet, are proposed to treat and prevent these disorders. Some studies demonstrated that saturated fatty acids (SFA) are considered detrimental for treating these disorders. A high fat diet rich in palmitic acid, a SFA, is associated with lower insulin sensitivity and it may also increase atherosclerosis parameters. On the other hand, a high intake of eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids may promote positive effects, especially on triglyceride levels and increased high-density lipoprotein (HDL) levels. Moreover, polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) are effective at limiting the hepatic steatosis process through a series of biochemical events, such as reducing the markers of non-alcoholic hepatic steatosis, increasing the gene expression of lipid metabolism, decreasing lipogenic activity, and releasing adiponectin. This current review shows that the consumption of unsaturated fatty acids, MUFA, and PUFA, and especially EPA and DHA, which can be applied as food supplements, may promote effects on glucose and lipid metabolism, as well as on metabolic inflammation, gut microbiota, and hepatic metabolism.
Dietary polyphenols come mainly from plant-based foods including fruits, vegetables, whole grains, coffee, tea, and nuts. Polyphenols may influence glycemia and type 2 diabetes (T2D) through different mechanisms, such as promoting the uptake of glucose in tissues, and therefore improving insulin sensitivity. This review aims to summarize the evidence from clinical trials and observational prospective studies linking dietary polyphenols to prediabetes and T2D, with a focus on polyphenol-rich foods characteristic of the Mediterranean diet. We aimed to describe the metabolic biomarkers related to polyphenol intake and genotype-polyphenol interactions modulating the effects on T2D. Intakes of polyphenols, especially flavan-3-ols, and their food sources have demonstrated beneficial effects on insulin resistance and other cardiometabolic risk factors. Several prospective studies have shown inverse associations between polyphenol intake and T2D. The Mediterranean diet and its key components, olive oil, nuts, and red wine, have been inversely associated with insulin resistance and T2D. To some extent, these associations may be attributed to the high amount of polyphenols and bioactive compounds in typical foods conforming this traditional dietary pattern. Few studies have suggested that genetic predisposition can modulate the relationship between polyphenols and T2D risk. In conclusion, the intake of polyphenols may be beneficial for both insulin resistance and T2D risk.
We investigated the association between dietary habits/food group consumption patterns and early risk of metabolic syndrome (MetS), a main cause for metabolic disease. Study participants were recruited from the health promotion center in Dong-A University Hospital and public advertisement. Study subjects (n = 243, 21–80 years) were categorized into three groups: Super-healthy (MetS risk factor [MetS RF] = 0, n = 111), MetS-risk carriers (MetS RF = 1–2, n = 96), and MetS (MetS RF ≥ 3, n = 27). Higher regularity in dietary habits (breakfast-everyday, regular eating time, non-frequent overeating, and non-frequent eating-out) was observed in the Super-healthy group than in the MetS-risk carriers, and particularly in the MetS subjects. The relationship between food group consumption patterns and MetS-risk related parameters were investigated with adjustment for confounding factors. Fruit consumption was positively associated with HDL-cholesterol, and tended to be negatively associated with waist circumference, triglyceride, LDL-cholesterol, and insulin resistance (IR). The consumption of low-fat meats and fish, and vegetables was negatively associated with hs-CRP. Specifically, the consumption of sea-foods belonging to the low-fat fish was negatively associated with fasting glucose, hs-CRP, and interleukin (IL)-6. Anchovy/dried white baits consumption was negatively associated with fasting insulin and IR. Green-yellow vegetables consumption was negatively associated with fasting insulin, IR, and hs-CRP. On the other hand, sugars and fast-foods were positively associated with LDL-cholesterol. Additionally, fast-foods consumption was positively associated with hs-CRP and IL-6 levels. In conclusion, dietary habits/food group consumption patterns are closely associated with MetS-risk related parameters in Koreans. It may suggest useful information to educate people to properly select healthy foods for early prevention of MetS.
Background: Fish consumption may have beneficial effects on metabolic syndrome (MetS);
however, limited information of such associations exists. This study investigated possible associations
between fish consumption and changes in MetS components during a 13-year follow-up period.
Methods: The sample included participants (26–69 years) from the Tromsø Study 4 (1994–1995,
n = 23,907) and Tromsø Study 6 (2007–2008, n = 12,981). Data were collected using questionnaires
including food frequency questions, non-fasting blood samples, and physical examinations. MetS
was defined using the Joint Interim Societies (JIS) definition, in which one point was given for each
MetS criteria fulfilled (metabolic score). Longitudinal analyses were performed using Linear mixed
models. Results: For both genders, lean fish consumption once a week or more was significantly
associated with decreased future metabolic score, decreased triglycerides, and increased high-density
lipoprotein (HDL)-cholesterol, whereas decreased waist circumference and blood pressure was
identified only for men (age adjusted models). Fatty fish consumption was significantly associated
with increased waist circumference for both genders and increased HDL-cholesterol levels in men.
Conclusion: The results suggest that fatty and lean fish consumption may influence MetS differently
and that lean fish consumption in particular seems to be associated with beneficial changes in the
MetS components.
Background
Although studies show that portion size affects energy intake, few have demonstrated a link between portion size and weight status, especially in free-living populations. The objective of the present study was to assess the relationship between food portion sizes and overweight in a representative population of adults of São Paulo, Brazil.
Methods
Cross-sectional population-based study with 1005 adults from São Paulo, Brazil. Dietary data were obtained from two 24-hour recalls. Reported foods were classified into groups and energy contribution, prevalence of consumers and portion sizes were calculated. Individuals were classified according to BMI in with and without overweight. Logistic regression models were used to evaluate the association between food portion sizes and being overweight.
Results
The most consumed food groups were: beans, breads/rolls, coffee/tea, milk, rice, and sugar. Rice, red meat, breads/rolls, and white meat were the groups with the highest percentage of contribution to total energy intake. Butter/margarine, toasts/biscuits, sugar, and cakes were the groups with the highest energy density. After adjustment for confounding variables, overweight was associated with larger portions of pizza (OR = 1.052; p = 0.048), red meat (OR = 1.025; p = 0.043), rice (OR = 1.033; p<0.001), salted snacks (OR = 1.078; p = 0.022), and soft drinks (OR = 1.016; p = 0.007).
Conclusions
Larger portions of few food groups with different energy densities were associated with being overweight, suggesting that overweight may be related to the consumption of larger portion sizes of a series of food groups, not a food group alone. Additionally, we highlight the importance of considering underreporting as a confounding factor in these associations.
Insulin resistance is a multi-faceted disruption of the communication between insulin and the interior of a target cell. The underlying cause of insulin appears to be inflammation that can either be increased or decreased by the fatty acid composition of the diet. However, the molecular basis for insulin resistance can be quite different in various organs. This review deals with various types of inflammatory inputs mediated by fatty acids, which affect the extent of insulin resistance in various organs.
Objective:
To examine the association between cardiorespiratory fitness and dietary patterns in adolescents.
Design:
Food choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants' height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI.
Setting:
Secondary schools in Otago, New Zealand.
Subjects:
Students (n 279) aged 14-18 years who completed an online lifestyle survey during a class period.
Results:
Principal components analysis produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables' and 'Basic Foods'. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The 'Fruits and Vegetables' pattern was positively associated with VO2max in the total sample (β=0·04; 95 %CI 0·02, 0·07), girls (β=0·06; 95 % CI 0·03, 0·10) and boys (β=0·03; 95 % CI 0·01, 0·05).
Conclusions:
These results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.
High-density lipoprotein (HDL) is a lipoprotein which has anti-atherogenic property by reversing cholesterol transport from the peripheral tissues to liver. Low HDL-cholesterol (HDL-C) as well as high low-density lipoprotein-cholesterol (LDL-C) is associated with the development of coronary heart diseases (CHD). Various epidemiological studies have suggested that the development of CHD increase in individuals with less than 40 mg/dL of HDL-C. In spite of accumulation of evidences suggesting a significant association between low HDL-C and CHD, effects of dietary factors on HDL metabolism remained largely unknown. We reviewed published articles about effects of dietary fat intake on HDL metabolism. The substitution of fatty acids (FA) for carbohydrates is beneficially associated with HDL metabolism. Monounsaturated FA intake may not affect HDL-C. Trans-FA is significantly associated with reduction of HDL-C, and is also adversely related with total cholesterol/HDL-C. Fish oils consumption, especially docosahexaenoic acid consumption, may be favorably associated with HDL metabolism. Although plant sterols and stanols may not affect HDL-C, policosanol intake is associated with a clinically significant decrease in the LDL/HDL ratio.
Insulin resistance is a significant cross-point for the manifestation of several chronic diseases in children and adults. The aim of the present study was to investigate the possible relationship of certain dietary patterns and breakfast consumption habits with insulin resistance in children.
A representative sample of 1912 schoolchildren (aged 9-13 years) participated in a cross-sectional epidemiological study, the Healthy Growth Study, which was initiated in May 2007 and completed in June 2009.
It was conducted in seventy-seven primary schools in four large regions in Greece.
Dietary intake, breakfast consumption, anthropometric and physical examination data, biochemical indices and socio-economic information collected from parents were assessed in all children. Principal components analysis was used to identify dietary patterns.
A dietary pattern of increased consumption of margarine, sweets (candies, lollipops, jellies, traditional fruit in heavy syrup) and savoury snacks (chips, cheese puffs and not home-made popcorn) was associated with homeostasis model assessment of insulin resistance index (HOMA-IR; β = 0·08, P < 0·001) in multivariate models. Children in the third tertile of this dietary pattern had a 2·51 (95 % CI 1·30, 4·90) times higher risk of insulin resistance (HOMA-IR > 3·16) than those in the first tertile. Breakfast consumption had an inverse correlation with insulin resistance, but the correlation lost its significance after adjustments for waist circumference, birth weight, parental BMI and socio-economic status.
Increased consumption of margarine, sweets and savoury snacks, which is a common dietary pattern in childhood, was positively associated with insulin resistance, while breakfast consumption had an inverse association with HOMA-IR, in schoolchildren (aged 9-13 years). Identification of dietary behaviours that might affect insulin resistance in children offers valuable advice in cardiometabolic risk prevention strategies.
Diet quality is influenced by socio-economic and geographical factors. The present study sought to assess whether adolescents' diet quality is affected by their parents' socio-economic status and whether the relationship between these factors is similar in northern and southern Europe. Data collected in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study in eight European countries were analysed. Dietary intake data were recorded via repeated 24 h recalls (using specifically developed HELENA Dietary Intake Assessment Tool software) and converted into an adolescent-specific Diet Quality Index (DQI-AM). Socio-economic status was estimated through parental educational level (Par-Educ-Lev) and parental occupation level (Par-Occ-Lev) as reported by the adolescents in a specific questionnaire. The DQI-AM data were then analysed as a function of Par-Educ-Lev and Par-Occ-Lev in northern European countries (Austria, Belgium, France, Germany and Sweden) and southern European countries (Greece, Italy and Spain). We studied a total of 1768 adolescents (age 14·7 (sd 1·3) years; percentage of girls: 52·8 %; 1135 and 633 subjects from northern and southern Europe, respectively). On average, the DQI-AM score was higher in southern Europe than in northern Europe (69·1 (sd 0·1) v. 60·4 (sd 2·8), respectively; P< 0·001; Δ = 12·6 %). The DQI was positively correlated with both paternal and maternal Par-Educ-Lev. However, this association was more pronounced in northern Europe than in southern Europe (P interaction = 0·004 for the mother and 0·06 for the father). The DQI was also positively correlated with Par-Occ-Lev (all P trends < 0·01), but this correlation was independent of the geographical area (P interaction = 0·51 for the mother and 0·50 for the father). In conclusion, Par-Educ-Lev and Par-Occ-Lev are associated with diet quality in adolescents in Europe. However, this association differs between northern Europe and southern Europe.
Metabolic syndrome (MetS) is a cluster of risk factors that significantly increases the risk of cardiovascular disease. The lack of universally accepted diagnosis criteria makes it difficult to know the real prevalence of MetS in both adult and pediatric population. Lifestyle, especially nutritional habits and physical activity, have been suggested to be independent risk factors for the development of MetS. Recent studies highlight the need to prioritize overall dietary patterns, rather than isolated nutrients, to better appraise the associations between nutritional habits and MetS. In this review we summarize recently published intervention trials and systematic reviews that evaluated the association between overall dietary patterns and the risk of MetS. Westernized dietary patterns, characterized by a high consumption of meat or meat products, snacks, baked desserts and sugar-sweetened beverages, which provide high amounts of saturated fatty acids and simple carbohydrates as added sugars, have been associated with higher risk of MetS. In contrast, more traditional dietary patterns, including the Mediterranean dietary pattern (MDP), characterized by a high consumption of vegetables, fruits, whole cereals and fish are associated with a reduced risk of MetS. The main characteristics of the MDP include a high consumption of nuts and olive oil, resulting in a relatively fat-rich pattern that provides high amounts of mono- and polyunsaturated fatty acids, bioactive polyphenols and dietary fiber. Strong evidence is accumulating to support that a closer conformity with the MDP is inversely associated with the incidence of MetS, cardiovascular risk factors, diabetes and cardiovascular disease.
Objective
High sodium (HS) diet is associated with hypertension (HT) and insulin resistance (IR). We evaluated whether HS diet was associated with a dysregulation of cortisol production and metabolic syndrome (MetS). Patients and measurementsWe recruited 370 adults (18-85years, BMI 29344kg/m(2), 70% women, 72% HT, 61% MetS). HS diet (urinary sodium >150mEq/day) was observed in 70% of subjects. We measured plasma hormones, lipid profile, urinary free cortisol (UFC) and cortisol tetrahydrometabolites (THM). ResultsUrinary sodium was correlated with UFC (r=+045, P<0001), cortisol THM (r=+041, P<0001) and inversely with adiponectin, HDL and aldosterone, after adjusting by age, gender and BMI. Subjects with high, compared with adequate sodium intake (50-149mEq/day) had higher UFC (P<0001), THM (P<0001), HOMA-IR (P=004), HT (81% vs 50%, P<0001), MetS (69% vs 41%, P<0001) and lower adiponectin (P=0003). A multivariate predictive model adjusted by confounders showed a high discriminative capacity for MetS (ROC curve 0878) using four clinical variables: HS intake [OR=56 (CI 23-153)], HOMA-IR [OR 17 (13-22)] cortisol THM [OR 12 (11-14)] and adiponectin [OR=09 (08-09)], the latter had a protective effect. Conclusions
High sodium diet was associated with increased urinary cortisol and its metabolites. Also, HS diet was associated with HT, insulin resistance, dyslipidaemia and hypoadiponectinaemia, even when adjusting by confounding variables. Further, we observed that high salt intake, IR and higher cortisol metabolites, alone or combined in a clinical simple model, accurately predicted MetS status, suggesting an additive mechanism in obesity-related metabolic disorders.
The HELENA Project—Healthy Lifestyle in Europe by Nutrition in Adolescence—is a European, collaborative research project financed by the EU Sixth Framework Programme in the area of nutrition-related
adolescent health. The basic objective of the HELENA project is to obtain reliable and comparable data from a random sample
of European adolescents (boys and girls aged 13–16years) on a broad battery of relevant nutrition and health-related parameters:
dietary intake, food choices and preferences, anthropometry, serum indicators of lipid metabolism and glucose metabolism,
vitamin and mineral status, immunological markers, physical activity, fitness and genetic markers. The HELENA project is conceived
as a scientific construction with four complementary sub-studies that are elaborated through 14 well-defined work packages.
Sub-studies are focused, respectively, on “a cross-sectional description of lifestyles and indicators of nutritional status
(HELENA-CSS)”, “a lifestyle education intervention programme (HELENA-LSEI), “a metabolic study with cross-over design (HELENA-COMS)”
and a “study on behaviour, food preferences and food development” (HELENA-BEFO). The project unites 20 research centres from
10 European countries. In addition, the consortium comprises five SMEs (small and medium-sized enterprises) that are actively
involved in the research activities. The core of the HELENA project study material is an overall European cohort of 3,000
adolescents, equally recruited in ten cities from nine countries. Standardization of methods among partners is a key issue
in the project and is obtained through the development of standard protocols, training sessions, validation sub-studies and
pilot projects. Health-related problems have a tendency to evolve in cycles, with ever new problems emerging in ever new contexts
that call for appropriate and tailored actions. The HELENA project is expected to offer essential elements for use in the
overall machinery of required public health nutrition cycles. It is of the greatest importance for its results to prove useful
that it can communicate with other initiatives on the level of science and society.
Obese adolescents have high concentrations of saturated fatty acids and low omega-3 long-chain polyunsaturated fatty acids (LCUFAs) in plasma phospholipids. We aimed to investigate effects of omega-3 LCPUFA supplementation to obese adolescents on skeletal muscle lipids and glucose and insulin homeostasis. Twenty-five obese adolescents (14-17 years old, 14 females) completed a randomized double-blind crossover study supplying capsules containing either 1.2 g omega-3 LCPUFAs or placebo, for 3 months each with a six-week washout period. Fasting blood glucose, insulin, leptin, adiponectin, and lipids were measured. Intravenous glucose tolerance test (IVGTT) and euglycemic-hyperinsulinemic clamp were performed, and skeletal muscle biopsies were obtained at the end of each period. The concentrations of EPA, DHA, and total omega-3 PUFA in muscle phospholipids increased in both sexes. In the females, omega-3 LCPUFA supplementation improved glucose tolerance by 39% (P = 0.04) and restored insulin concentration by 34% (P = 0.02) during IVGTT. Insulin sensitivity improved 17% (P = 0.07). In males, none of these parameters was influenced by omega-3 supplementation. Thus, three months of supplementation of omega-3 LCPUFA improved glucose and insulin homeostasis in obese girls without influencing body weight.
Dietary pattern may influence the risks of cardiovascular disease, atherosclerosis, type 2 diabetes, and metabolic syndrome through its effects on inflammation. We evaluated the association between dietary pattern and serum high-sensitivity C-reactive protein (hs-CRP) in a Japanese population.
In this cross-sectional analysis, we used baseline data from 3905 men and 5640 women (age 40-69 years) who participated in a population-based cohort study between November 2005 and December 2007. Participants with possible inflammation-related diseases, current analgesic use, high hs-CRP levels (≥3000 ng/mL) or extreme dietary energy intake were excluded. We used 46 items from a validated short food frequency questionnaire and examined major dietary patterns by factor analysis.
We identified 5 dietary patterns: healthy (high in vegetables and fruit), Western (high in meat and fried foods), seafood (high in shellfish, squid, fish, etc.), bread (high in bread and low in rice), and dessert (high in confections and fruit). After adjustment for age, alcohol use, smoking, physical activity, and body mass index, hs-CRP levels in men were inversely associated with the healthy, bread, and dessert patterns (P-trend: 0.01, 0.06, and <0.01, respectively) and positively associated with the seafood pattern (P-trend = 0.02). In women, hs-CRP levels were inversely associated with the healthy pattern (P-trend = 0.06) and positively associated with the Western pattern (P-trend = 0.06).
The healthy dietary pattern may be associated with suppressed inflammation in Japanese men and women, independently of body mass index and other factors. The sex-specific associations of hs-CRP with other dietary patterns (eg, the seafood pattern) require further study.
Quercetin, a natural polyphenolic flavonoid substance present in a variety of food plants, has been shown in vitro and in animal studies to have widespread health and performance benefits resulting from a combination of biological properties, including antioxidant and anti-inflammatory activity, as well as the ability to increase mitochondrial biogenesis. Little is known about these effects in humans, however, especially with respect to exercise performance. The authors determined whether quercetin ingestion would enhance maximal aerobic capacity and delay fatigue during prolonged exercise in healthy but untrained participants. Twelve volunteers were randomly assigned to 1 of 2 treatments: (a) 500 mg of quercetin twice daily dissolved in vitamin-enriched Tang or (b) a nondistinguishable placebo (Tang). Baseline VO2max and bike-ride times to fatigue were established. Treatments were administered for a period of 7 days using a randomized, double-blind, placebo-controlled, crossover study design. After treatment both VO2max and ride time to fatigue were determined. Seven days of quercetin feedings were associated with a modest increase in VO2max (3.9% vs. placebo; p < .05) along with a substantial (13.2%) increase in ride time to fatigue (p < .05). These data suggest that as little as 7 days of quercetin supplementation can increase endurance without exercise training in untrained participants. These benefits of quercetin may have important implications for enhancement of athletic and military performance. This apparent increase in fitness without exercise training may have implications beyond that of performance enhancement to health promotion and disease prevention.
To review and summarize the dietary determinants of the metabolic syndrome, subclinical inflammation and dyslipidemia in overweight children.
Review of the current literature, focusing on pediatric studies.Participants:Normal weight, overweight, or obese children and adolescents.
There is a growing literature on the metabolic effects of excess body fat during childhood. However, few pediatric studies have examined the dietary determinants of obesity-related metabolic disturbances. From the available data, it appears that dietary factors are not only important environmental determinants of adiposity, but also may affect components of the metabolic syndrome and modulate the actions of adipokines. Dietary total fat and saturated fat are associated with insulin resistance and high blood pressure, as well as obesity-related inflammation. In contrast to studies in adults, resistin and adiponectin do not appear to be closely linked to insulin resistance or dyslipidemia in childhood. However, circulating leptin and retinol-binding protein (RBP) 4 correlate well with obesity, central obesity and the metabolic syndrome in children. Intakes of antioxidant vitamins tend to be low in obese children and may be predictors of subclinical inflammation. Higher fructose intake from sweets and sweetened drinks in overweight children has been linked to decreased low-density lipoprotein (LDL) particle size.
Dietary interventions aimed at reducing intakes of total fat, saturated fat and free fructose, whereas increasing antioxidant vitamin intake may be beneficial in overweight children. More research on the relationships between dietary factors and the metabolic changes of pediatric obesity may help to identify the dietary changes to reduce health risks.
Analysis of several biological markers improves the quality and physiologic comprehension of data obtained in epidemiological nutritional studies.
To develop a methodology that guarantees the centralized analysis and quality assurance of the most relevant blood parameters from fresh blood samples in adolescents in a European multicenter study.
Stability of selected nutrients and biomarkers (vitamins, fatty acids, iron metabolism and immunological parameters) chosen with respect to time and temperature of sample transport and storage was evaluated as part of the pilot study of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) project.
Routine biochemistry and iron status parameters included in the HELENA Cross-Sectional Study (CSS) protocol could be analyzed within 24 h from fresh blood samples without any stability problems (coefficient of variation (CV)<5%, P<0.05). However, stability tests for lymphocyte subpopulations, vitamin C and fatty acids showed that they are very unstable at room temperature without any treatment. Therefore, a special handling for these samples was developed. Vitamin C was stabilized with metaphosphoric acid and transported under cooled conditions (CV 4.4%, recovery rate >93%, P>0.05). According to the results, a specific methodology and transport system were developed to collect blood samples at schools in 10 European cities and to send them to the centralized laboratory (IEL, Bonn, Germany). To guarantee good clinical practice, the field workers were instructed in a training workshop and a manual of operation was developed.
The handling and transport system for fresh blood samples developed for the European multicenter study HELENA is adequate for the final part of the HELENA-CSS and will provide, for the first time, reference values for several biological markers in European adolescents.
To describe the standardization process and reliability of anthropometric and bioelectrical impedance analysis (BIA) measurements. We examined both intra- and interobserver errors for skinfolds, circumferences and BIA.
For the intraobserver error assessment, first of all, 202 adolescents in the pilot study (110 boys, 92 girls, aged 13.64+/-0.78 years) were assessed. For the second intraobserver and interobserver assessments, 10 adolescents were studied (5 boys and 5 girls).
The pilot study's intraobserver technical errors of measurement (TEMs) were between 0.12 and 2.9 mm for skinfold thicknesses, and between 0.13 and 1.75 cm for circumferences. Intraobserver reliability for skinfold thicknesses was greater than 69.44% and beyond 78.43% for circumferences. The final workshop's intraobserver TEMs for skinfold thicknesses and circumferences were smaller than 1; for BIA resistance TEMs were smaller than 0.1 Omega and for reactance they were smaller than 0.2 Omega. Intraobserver reliability values were greater than 95, 97, 99 and 97% for skinfold thicknesses, circumferences, BIA resistance and reactance, respectively. Interobserver TEMs for skinfold thicknesses and circumferences ranged from 1 to 2 mm; for BIA they were 1.16 and 1.26 Omega for resistance and reactance, respectively. Interobserver reliability for skinfold thicknesses and circumferences were greater than 90%, and for BIA resistance and reactance they were greater than 90%.
After the results of the pilot study, it was necessary to optimize the quality of the anthropometric measurements before the final survey. Significant improvements were observed in the intraobserver reliabilities for all measurements, with interobserver reliabilities being higher than 90% for most of the measurements.The Healthy Lifestyle in Europe by Nutrition in Adolescence Study aims to describe total body fat percentage and anthropometric indices of body fat distribution in European adolescents.
The International Physical Activity Questionnaire (IPAQ) was developed to measure health-enhancing physical activity in adult populations. This study explores the concurrent validity of a modified version of the long IPAQ (the IPAQ-A) for the assessment of physical activity among adolescents.
In total, 248 healthy adolescents, divided into one older and one younger age group (aged 15-17 years (N=188) and 12-14 years (N=60), respectively) from nine Healthy Lifestyle by Nutrition in Adolescence (HELENA) Study centres across Europe, voluntarily participated in the study. Data on total physical activity, as well as activities in different intensities derived from the IPAQ-A, were compared using Spearman's correlation coefficient and Bland-Altman analysis, with data from an accelerometer. Tertiles of total physical activity for the IPAQ-A and the accelerometer were compared using Kendall's tau-b.
For the older age group, significant correlations between the instruments were found for time spent walking, for moderate and vigorous activities as well as for total physical activity (Rs=0.17-0.30, P<0.05). No significant correlations were found for any of the variables studied in the younger age group. Kendall's tau-b showed low but significant correlations for tertiles of total physical activity (P<0.001).
The IPAQ-A has reasonable validity properties for assessing activities in different intensities and for total physical activity in healthy European adolescents aged 15-17 years. For adolescents aged 14 years and younger, the correlations were unsatisfactorily low and objective methodology, such as accelerometry, may be the appropriate alternative.
To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.
Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.
The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.
The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.
To describe the development of a European computerized 24-h dietary recall method for adolescents, and to investigate the feasibility of self-administration (self report) by comparison with administration by a dietician (interview).
Two hundred and thirty-six adolescents (mean age 14.6 years (s.d.=1.7)) of eight European cities completed the 24-h recall (Young Adolescents Nutrition Assessment on Computer (YANA-C)) twice (once by self-report and once by interview).
A small but significant underestimate in energy (61 (s.e.=31) kcal) and fat (4.2 (s.e.=1.7) g) intake was found in the self-reports in comparison with the interviews; no significant differences were found for the intake of carbohydrates, proteins, fibre, calcium, iron and ascorbic acid. Spearman's correlations were highly significant for all nutrients and energy ranging between 0.86 and 0.91. Agreement in categorizing the respondents as consumers and non-consumers for the 29 food groups was high (kappa statistics >or=0.73). Percentage omissions were on average 3.7%; percentage intrusions: 2.0%. Spearman's correlations between both modes were high for all food groups, for the total sample (>or=0.76) as well as for the consumers only (>or=0.72). Analysing the consumer only, on an average 54% of the consumed amounts were exactly the same; nevertheless, only for one group 'rice and pasta' a significant difference in consumption was found.
Adaptation, translation and standardization of YANA-C make it possible to assess the dietary intake of adolescents in a broad international context. In general, good agreement between the administration modes was found, the latter offering significant potential for large-scale surveys where the amount of resources to gather data is limited.
Rationale:
Research involving humans is regulated by regulatory authorities through their specific requirements and controls. The Healthy Life Style in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) is a multicenter biomedical research study of adolescents in several representative European cities, which requires satisfying medico-regulatory requirements including Independent Ethics Committee (IEC) approval and agreement by the national or local regulatory authorities. To achieve a high level of quality assurance relating to ethical issues, we followed the good clinical practices (GCP) described at the International Conference on Harmonisation (ICH), which we adapted to the national and local situations of each of the 11 participating cities in 10 European countries.
Objective:
The main objective of the HELENA-CSS is to evaluate reliable and comparable data of nutritional habits and lifestyle in a representative sample of European adolescents. The aim of this paper is to present the methods relating to the ethical and regulatory issues of this study and to describe the current state of the medico-regulatory requirements involved in conducting this kind of study in each country.
Materials and methods:
Following the GCP-ICH guidelines, a protocol describing the HELENA-CSS was written and approved by all partners. In the pilot study, a case report form adapted to the study objectives and its manual of operation was constructed and used by all partners. All information letters to adolescents and their parents and consent forms were first written in English, then translated into the local language, and adapted to each local situation. All documents were then checked centrally for any deviation and corrected if required. An operation manual relating to ethical issues and other medico-regulatory requirements was also developed. This paper presents the current status of the medico-regulatory requirements from each HELENA-CSS participant country.
Results:
Before the beginning of the study, most centers had satisfied the medico-regulatory requirements of IEC approval and agreement with other national or local regulatory authorities/organizations. For a few centers, some problems were detected and corrective actions were taken to improve missing information to reach a high level of quality assurance of ethical issues.
Conclusion:
The GCP-ICH guidelines about nontherapeutic biomedical research are interpreted and applied differently across Europe. This study shows that high-quality nontherapeutic biomedical research can address the ethical issues included in the GCP-ICH regulations and can be harmonized among the HELENA European partners.
We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.
Previous studies indicate that leptin secretion is regulated by insulin-mediated glucose metabolism. Because fructose, unlike glucose, does not stimulate insulin secretion, we hypothesized that meals high in fructose would result in lower leptin concentrations than meals containing the same amount of glucose. Blood samples were collected every 30-60 min for 24 h from 12 normal-weight women on 2 randomized days during which the subjects consumed three meals containing 55, 30, and 15% of total kilocalories as carbohydrate, fat, and protein, respectively, with 30% of kilocalories as either a fructose-sweetened [high fructose (HFr)] or glucose-sweetened [high glucose (HGl)] beverage. Meals were isocaloric in the two treatments. Postprandial glycemic excursions were reduced by 66 +/- 12%, and insulin responses were 65 +/- 5% lower (both P < 0.001) during HFr consumption. The area under the curve for leptin during the first 12 h (-33 +/- 7%; P < 0.005), the entire 24 h (-21 +/- 8%; P < 0.02), and the diurnal amplitude (peak - nadir) (24 +/- 6%; P < 0.0025) were reduced on the HFr day compared with the HGl day. In addition, circulating levels of the orexigenic gastroenteric hormone, ghrelin, were suppressed by approximately 30% 1-2 h after ingestion of each HGl meal (P < 0.01), but postprandial suppression of ghrelin was significantly less pronounced after HFr meals (P < 0.05 vs. HGl). Consumption of HFr meals produced a rapid and prolonged elevation of plasma triglycerides compared with the HGl day (P < 0.005). Because insulin and leptin, and possibly ghrelin, function as key signals to the central nervous system in the long-term regulation of energy balance, decreases of circulating insulin and leptin and increased ghrelin concentrations, as demonstrated in this study, could lead to increased caloric intake and ultimately contribute to weight gain and obesity during chronic consumption of diets high in fructose.
Aim
To assess the association between dietary patterns no single food or group, and risk of insulin resistance (Fasting blood sugar (FBS), Fasting insulin, 2h-glucose, 2h-insulin and HOMA-IR).
Methods
In a cross-sectional, population-based study in Tehran, Iran, 2016–2017. Adults (n = 1500, 38% men) mean age 43.72 ± 14.9 years. Dietary intake was collected by semi-quantitative food frequency questionnaire and insulin resistance was evaluated by Fasting blood sugar (FBS), Fasting insulin, 2h glucose, 2h insulin and HOMA-IR. Associations were assessed by using correlation and multivariable linear regression.
Results
After controlling of the confounding factor or possible underlying such as gender, age, menopausal, BMI, physical activity and the amount of daily energy intake, unhealthy dietary pattern had a positive relationship with all indexes of insulin resistance except 2h glucose and HOMA-IR, healthy dietary pattern had negative and significant relationship with indexes of insulin resistance but apart from 2h glucose.
Conclusions
It can be figured out that receiving diet rich in healthy foods might reduce the risk of creating insulin resistance.
Background:
The incidence of type 2 diabetes mellitus (T2DM) in children and adolescents is increasing, mirroring the epidemic of paediatric obesity. Early-onset T2DM is associated with poor long-term outcomes.
Objective:
In this article, we describe the growing problem of early-onset T2DM in Australia, explore the difference between early-onset and adult-onset T2DM, and review the management of T2DM in children and adolescents.
Discussion:
T2DM is difficult to differentiate from the more common type 1 diabetes mellitus (T1DM) in the paediatric population. Risk factors for T2DM include obesity, ethnicity and family history, and adolescence is a predisposing time for the development of T2DM due to physiological insulin resistance. Early-onset T2DM is more associated with shorter duration to insulin requirement, development of diabetic complications and cardiovascular disease than adult-onset T2DM and T1DM. The main goals in management include normalising hyperglycaemia, facilitating lifestyle modifications and managing diabetes-related and obesity-related comorbidities.
The present study examined the associations of food behaviours and preferences with markers of insulin resistance and clustered metabolic risk factors score after controlling for potential confounders, including body fat in European adolescents. A cross-sectional study "Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study" of 3546 European adolescents aged 12.5-17.5 years was conducted, using a complete dataset on at least glucose, insulin and "Food Choice Questionnaire". Results indicated skipping breakfast, as well as the preference of some foods such as nuts, chocolate, burgers and pizzas, soft drinks or juices, explain part of homeostasis model assessment index variance. In addition, snacking regularly during school day is associated with higher metabolic risk score in females. In conclusion, the present findings suggest that intervention studies aimed to prevent insulin resistance and metabolic risk factors in youth should focus not only in influencing food and drink preferences, but also to ensure healthy food behaviour in adolescents. The harmful consequences in the choice of certain foods or drinks and food habits can be countered with proper planning and intervention programs to prevent insulin resistance and metabolic risk factors.
Objective
To develop an internationally acceptable definition of child overweight and obesity, specifying the measurement, the reference population, and the age and sex specific cut off points.
Design
International survey of six large nationally representative cross sectional growth studies.
Setting
Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States
Subjects
97 876 males and 94 851 females from birth to 25 years of age
Main outcome measure
Body mass index (weight/height2).
Results
For each of the surveys, centile curves were drawn that at age 18 years passed through the widely used cut off points of 25 and 30 kg/m2 for adult overweight and obesity. The resulting curves were averaged to provide age and sex specific cut off points from 2-18 years.
Conclusions
The proposed cut off points, which are less arbitrary and more internationally based than current alternatives, should help to provide internationally comparable prevalence rates of overweight and obesity in children.
Insulin-mediated glucose disposal varies at least sixfold in apparently healthy individuals. The adverse effect of decreases in the level of physical fitness on insulin sensitivity is comparable to the untoward impact of excess adiposity, with each accounting for approximately 25% of the variability of insulin action. It is the loss of insulin sensitivity that explains why obese individuals are more likely to develop cardiovascular disease, but not all overweight/obese individuals are insulin resistant. At a clinical level, it is important to identify those overweight individuals who are also insulin resistant and to initiate the most intensive therapeutic effort in this subgroup. Finally, it appears that the adverse impact of overall obesity, as estimated by body mass index, is comparable to that of abdominal obesity, as quantified by waist circumference.
This study was undertaken to assess magnesium intake and magnesium status in patients with type 2 diabetes, and to identify the parameters that best predict alterations in fasting glucose and plasma magnesium.
A cross-sectional study was carried out in patients with type 2 diabetes (n = 51; 53.6 ± 10.5 y) selected within the inclusion factors, at the University Hospital Onofre Lopes. Magnesium intake was assessed by three 24-h recalls. Urine, plasma and erythrocytes magnesium, fasting and 2-h postprandial glucose, HbA1, microalbuminuria, proteinuria, and serum and urine creatinine were measured.
Mean magnesium intake (9.37 ± 1.76 mmol/d), urine magnesium (2.80 ± 1.51 mmol/d), plasma magnesium (0.71 ± 0.08 mmol/L) and erythrocyte magnesium (1.92 ± 0.23 mmol/L) levels were low. Seventy-seven percent of participants presented one or more magnesium status parameters below the cut-off points of 3.00 mmol/L for urine, 0.75 mmol/L for plasma and 1.65 mmol/L for erythrocytes. Subjects presented poor blood glucose control with fasting glucose of 8.1 ± 3.7 mmol/L, 2-h postprandial glucose of 11.1 ± 5.1 mmol/L, and HbA1 of 11.4 ± 3.0%. The parameters that influenced fasting glucose were urine, plasma and dietary magnesium, while plasma magnesium was influenced by creatinine clearance.
Magnesium status was influenced by kidney depuration and was altered in patients with type 2 diabetes, and magnesium showed to play an important role in blood glucose control.
To examine the dietary intake of total sugar, added sugar, non-added sugar and starch as well as dietary fibre and glycaemic index (GI) and their respective associations with insulin resistance.
Mixed linear models were used to study both cross-sectional and prospective associations between carbohydrate components and insulin resistance separately in girls and boys. Diet was assessed by a single 24 h recall interview and insulin resistance was calculated using the homoestasis model assessment (HOMA).
The Danish part of the European Youth Heart Studies (EYHS) I and II.
Girls and boys at 8-10 and 14-16 years from EYHS I (n 651) and 8-10-year-olds from baseline followed up 6 years later in EYHS II (n 233).
Among girls, a difference in dietary total sugar of 43 g/MJ was associated with a 1 sd difference of HOMA and a difference in dietary fibre of -8 g/MJ was associated with a 1 sd difference of HOMA, independent of age, maturity and other confounders (both P = 0.03). No baseline associations were found among boys and no prospective associations were found in either sex.
Dietary intake of total sugar may play an adverse role and fibre may play a beneficial role in concurrent insulin resistance among girls but not boys. Sex differences may be due to differences in maturity, physical activity, food patterns and selective reporting behaviours.
Obesity is a chronic disease that is increasing in prevalence in the United States and worldwide and is often accompanied by multiple comorbidities that lead to type 2 diabetes and cardiovascular disease. In April 2009, the American Society for Nutrition hosted the symposium "An Integrative View of Obesity" at Experimental Biology 2009 in New Orleans, LA. The presentations addressed the causes of the obesity epidemic and notably discussed a combination of genetics, obesogenic environment, cultural and racial concerns, and treatment modalities based on what we have learned from research into the physiology and neuroendocrine regulation of appetite and satiety. The fat cell as an endocrine organ, in addition to contributions from the gut and pancreas, has helped us to understand the origins of this neuroendocrine regulation as a survival advantage in human ancestry, with obesogenic ramifications in today's toxic food environment. Suggestions for the reversal of the obesity epidemic were offered, including public health campaigns, community and medical programs, and industry-supported change in our food supply, eating patterns, and lifestyle. Community-structured programs for exercise and work-related physical activity could also engage a healthier lifestyle into the typical day for the average American as well as for individuals in other countries.
Insulin resistance (IR) and hypertension are common in overweight children, and the adipocyte-derived hormones resistin, adiponectin, and leptin may modulate IR and blood pressure (BP). Few data exist in children on dietary determinants of IR, BP, or leptin, and no data exist on dietary determinants of resistin and adiponectin. Therefore, the objective of this study was to investigate dietary determinants of IR, BP, resistin, adiponectin, and leptin concentrations, as well as the interrelationship among these variables, in normal and overweight children.
In 6- to 14-year-old Swiss children (n=79), nutritional intake was assessed using two 24-hour-recalls and a one-day dietary record. Body mass index (BMI), body fat percentage (BF%), waist/hip ratio (W/H ratio), BP, glucose, insulin, resistin, adiponectin, and leptin were determined. IR was calculated using the quantitative insulin sensitivity check index (QUICKI).
BMI, BF%, and W/H ratio were significant predictors of leptin and insulin, QUICKI, and systolic BP, but not resistin or adiponectin. Of the overweight and obese children, 40% were diagnosed pre-hypertensive or hypertensive. Total energy, fat, saturated fat, and protein intakes were significant predictors of fasting insulin and QUICKI, and total fat, saturated fat, and monounsaturated fat intakes were significant predictors of systolic BP, independent of BMI standard deviation score (BMI-SDS) and age. There were no associations between these dietary factors and leptin, adiponectin, or resistin.
In children, dietary macronutrient composition is a predictor of IR and systolic BP, but not resistin, adiponectin, or leptin concentrations. Resistin and adiponectin concentrations are not correlated with IR or BP in this age range.
Overweight and other risk factors for cardiovascular disease (CVD) as well as their clustering, are increasingly prevalent among adolescents. We examined dietary patterns, CVD risk factors, and the clustering of these risk factors in 1139 14-year-olds living in Western Australia.
Usual dietary intake was assessed using a food frequency questionnaire. Two dietary patterns, 'Western' and 'Healthy', were identified using factor analysis. Associations between these dietary patterns and BMI, waist circumference, systolic blood pressure, fasting levels of serum glucose, insulin, total cholesterol, HDL-C, LDL-C, triglycerides and insulin resistance were assessed using ANOVA. Cluster analysis identified a high risk group (the 'high risk metabolic cluster') with features akin to adult metabolic syndrome. Belonging to the 'high risk metabolic cluster' was examined in relation to dietary patterns using logistic regression, adjusting for aerobic fitness and socio-demographic factors. Higher 'Western' dietary pattern scores were associated with greater odds for the 'high risk metabolic cluster' (p for trend=0.02) and greater mean values for total cholesterol (p for trend=0.03), waist circumference (p for trend=0.03) and BMI (p for trend=0.02) in girls, but not boys. Scores for the 'Healthy' dietary pattern were not related to the 'high risk metabolic cluster' but were inversely associated with serum glucose in boys and girls (p for trend=0.01 and 0.04, respectively) and were positively associated with HDL-C in boys (p for trend=0.02).
Dietary patterns are associated with CVD risk factors and the clustering of these risk factors in adolescence.
Insulin-mediated glucose disposal varies at least sixfold in apparently healthy individuals. The adverse effect of decreases in the level of physical fitness on insulin sensitivity is comparable to the untoward impact of excess adiposity, with each accounting for approximately 25% of the variability of insulin action. It is the loss of insulin sensitivity that explains why obese individuals are more likely to develop cardiovascular disease, but not all overweight/obese individuals are insulin resistant. At a clinical level, it is important to identify those overweight individuals who are also insulin resistant and to initiate the most intensive therapeutic effort in this subgroup. Finally, it appears that the adverse impact of overall obesity, as estimated by body mass index, is comparable to that of abdominal obesity, as quantified by waist circumference.
This paper uses fundamental principles of energy physiology to define minimum cut-off limits for energy intake below which a person of a given sex, age and body weight could not live a normal life-style. These have been derived from whole-body calorimeter and doubly-labelled water measurements in a wide range of healthy adults after due statistical allowance for intra- and interindividual variance. The tabulated cut-off limits, which depend on sample size and duration of measurements, identify minimum plausible levels of energy expenditure expressed as a multiple of basal metabolic rate (BMR). CUT-OFF 1 tests whether reported energy intake measurements can be representative of long-term habitual intake. It is set at 1.35 x BMR for cases where BMR has been measured rather than predicted. CUT-OFF 2 tests whether reported energy intakes are a plausible measure of the food consumed during the actual measurement period, and is always more liberal than CUT-OFF 1 since it has to allow for the known measurement imprecision arising from the high level of day-to-day variability in food intake. The cut-off limits can be used to evaluate energy intake data. Results falling below these limits must be recognized as being incompatible with long-term maintenance of energy balance and therefore with long-term survival.
We examined the relation of general and visceral adiposity to plasma hemostatic factors [fibrinogen, D-dimer, and plasminogen activator inhibitor 1 (PAI-1)] in obese boys and girls 7-11 y of age (n = 41). Boys had significantly greater fibrinogen and D-dimer concentrations than girls (P < 0.05). whereas blacks had significantly greater fibrinogen and D-dimer concentrations than whites (P < 0.05). Univariate analyses revealed that fibrinogen was positively associated with percentage body fat (%BF) (r = 0.42, P < 0.01), subcutaneous abdominal adipose tissue (SAAT) (r = 0.40, P < 0.01), total fat mass (r = 0.42, P < 0.01), and body mass index (r = 0.41, P < 0.01). PAI-1 was positively associated with visceral adipose tissue (VAT) (r = 0.49, P < 0.01), SAAT (r = 0.32, P < 0.05), fat-free mass (r = 0.50, P < 0.01), and insulin (r = 0.61, P < 0.001). D-Dimer was positively associated with %BF (r = 0.40, P < 0.01), SAAT (r = 0.37, P < 0.05), total fat mass (r = 0.40, P < 0.01), and body mass index (r = 0.43, P < 0.01). Multiple regression analysis revealed that for fibrinogen, sex and higher %BF explained significant independent portions of the variance. For PAI-1, higher amounts of VAT and fat-free mass were significant predictors. For D-dimer, ethnicity was a significant predictor. These results suggest that general adiposity and VAT may play a role in regulating plasma hemostatic factors in obese children. Even early in childhood, adiposity is associated with unfavorable concentrations of hemostatic factors that are in turn implicated in cardiovascular morbidity and mortality later in life.
Insulin resistance plays an important role in the pathophysiology of diabetes and is associated with obesity and other cardiovascular risk factors. The "gold standard" glucose clamp and minimal model analysis are two established methods for determining insulin sensitivity in vivo, but neither is easily implemented in large studies. Thus, it is of interest to develop a simple, accurate method for assessing insulin sensitivity that is useful for clinical investigations. We performed both hyperinsulinemic isoglycemic glucose clamp and insulin-modified frequently sampled iv glucose tolerance tests on 28 nonobese, 13 obese, and 15 type 2 diabetic subjects. We obtained correlations between indexes of insulin sensitivity from glucose clamp studies (SI(Clamp)) and minimal model analysis (SI(MM)) that were comparable to previous reports (r = 0.57). We performed a sensitivity analysis on our data and discovered that physiological steady state values [i.e. fasting insulin (I(0)) and glucose (G(0))] contain critical information about insulin sensitivity. We defined a quantitative insulin sensitivity check index (QUICKI = 1/[log(I(0)) + log(G(0))]) that has substantially better correlation with SI(Clamp) (r = 0.78) than the correlation we observed between SI(MM) and SI(Clamp). Moreover, we observed a comparable overall correlation between QUICKI and SI(Clamp) in a totally independent group of 21 obese and 14 nonobese subjects from another institution. We conclude that QUICKI is an index of insulin sensitivity obtained from a fasting blood sample that may be useful for clinical research.
The role of artificial sweeteners in body-weight regulation is still unclear.
We investigated the effect of long-term supplementation with drinks and foods containing either sucrose or artificial sweeteners on ad libitum food intake and body weight in overweight subjects.
For 10 wk, overweight men and women consumed daily supplements of either sucrose [n = 21, body mass index (BMI; in kg/m(2)) = 28.0] or artificial sweeteners (n = 20, BMI = 27.6). On average, sucrose supplements provided 3.4 MJ and 152 g sucrose/d and sweetener supplements provided 1.0 MJ and 0 g sucrose/d.
After 10 wk, the sucrose group had increases in total energy (by 1.6 MJ/d), sucrose (to 28% of energy), and carbohydrate intakes and decreases in fat and protein intakes. The sweetener group had small but significant decreases in sucrose intake and energy density. Body weight and fat mass increased in the sucrose group (by 1.6 and 1.3 kg, respectively) and decreased in the sweetener group (by 1.0 and 0.3 kg, respectively); the between-group differences were significant at P < 0.001 (body weight) and P < 0.01 (fat mass). Systolic and diastolic blood pressure increased in the sucrose group (by 3.8 and 4.1 mm Hg, respectively) and decreased in the sweetener group (by 3.1 and 1.2 mm Hg, respectively).
Overweight subjects who consumed fairly large amounts of sucrose (28% of energy), mostly as beverages, had increased energy intake, body weight, fat mass, and blood pressure after 10 wk. These effects were not observed in a similar group of subjects who consumed artificial sweeteners.
The greater energy content of larger food portions could be contributing to the increasing prevalence of overweight. Prevention guidelines recommend "sensible" portion sizes but do not define them. The US Department of Agriculture (USDA) defines standard serving sizes for dietary guidance, and the Food and Drug Administration (FDA) defines standard servings for food labels. To use these standards in counseling, nutritionists must know the sizes of portions available in the marketplace. We determined marketplace portion sizes, identified changes in these sizes with time, and compared current marketplace portions with federal standards. Most marketplace portions exceed standard serving sizes by at least a factor of 2 and sometimes 8-fold. Portions have increased over time; those offered by fast-food chains, for example, often are 2 to 5 times larger than the original size. The discrepancy between marketplace portions and standard servings suggests the need for greater emphasis on the relationship of portion size to energy intake as a factor in weight maintenance.
The metabolic syndrome is defined as the coexistence of 3 or more components, some of which indicate alterations in glucose and lipid metabolism. The prevalence of the metabolic syndrome is rapidly increasing in relation to obesity, and it is considered to be an important predictor of cardiovascular disease. Increased intakes or supplements of n-3 marine fatty acids may improve defects in insulin signaling and prevent alterations in glucose homeostasis and the further development of type 2 diabetes. This is largely mediated through a reduction in fatty acid accumulation in muscle and liver. n-3 Polyunsaturated fatty acids (n-3 PUFAs) reduce plasma triacylglycerols and improve the lipoprotein profile by decreasing the fraction of atherogenic small, dense LDL. However, n-3 PUFAs do not lower LDL cholesterol. These effects are likely mediated through the activity of transcription factors relating to expression of genes involved in lipid oxidation and synthesis. Other pleiotrophic effects of n-3 PUFAs may contribute to decreasing the burden of the metabolic syndrome, such as modulating inflammation, platelet activation, endothelial function, and blood pressure. Although studies comparing the effect of both major n-3 PUFAs are limited, docosahexaenoic acid appears at least as efficient as eicosapentaenoic acid in correcting several risk factors. The use of n-3 PUFAs should be considered in more global strategies including changes in lifestyle, such as adhering to a healthy Mediterranean type of diet and practicing regular physical exercise.