Figure - available via license: Creative Commons Attribution 2.0 Generic
Content may be subject to copyright.
Individual changes in trunk fat mass in men (upper panels) and women (lower panels) who started on a very low-carbohydrate ketogenic (VLCK) and switched to a low-fat (LF) diet (left panels) and vice versa (right panels). Mean response is shown in red.
Source publication
To compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK) and low-fat (LF) diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE) in overweight/obese men and women.
Randomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restric...
Similar publications
Objective:
Endogenous acetone production is a by-product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate wi...
Fat loss in response to exercise training varies between individuals, even when differences in compliance to the exercise program are accounted for. The purpose of this study was to investigate whether individual variation in change in fasting respiratory quotient (RQ) after exercise training contributes to this interindividual variability. Fifty-f...
Citations
... The perception of rapid weight loss in LoCHO diets has often been linked to changes in body water content rather than fat loss (Fig 3). However, various studies indicate that this transient water shift normalizes within two to three weeks, leading to actual fat mass reduction (Brehm et al., 2003;Freedman et al., 2001;Volek et al., 2004). Recent research revealed that adopting a low-carb diet led to a daily energy deficit of 1027 kcal and a reduction in average daily caloric intake from 3111 to 2164 kcal. ...
Biotechnology is one of the emerging fields that can add new and better application in a wide range of sectors like health care, service sector, agriculture, and processing industry to name some. This book will provide an excellent opportunity to focus on recent developments in the frontier areas of Biotechnology and establish new collaborations in these areas. The book will highlight multidisciplinary perspectives to interested biotechnologists, microbiologists, pharmaceutical experts, bioprocess engineers, agronomists, medical professionals, sustainability researchers and academicians. This technical publication will provide a platform for potential knowledge exhibition on recent trends, theories and practices in the field of Biotechnology
... LCDs thus promote a reduced demand for insulin secretion, facilitating improved glycemic control [63] and reducing glucose toxicity, oxidative stress, and inflammation which can affect beta-cell function [56]. The decreased insulin levels promote the activation of hormone-sensitive li-Nutrients 2024, 16, 95 9 of 14 pase (HSL) that facilitates the breakdown of stored triglycerides in adipose tissue, releasing fatty acids into the bloodstream for energy utilization [64,65]. This process contributes to a decrease in circulating triglycerides and an increase in fatty acid oxidation. ...
Introduction:
The worldwide prevalence of type 2 diabetes mellitus (T2DM) and obesity has been steadily increasing over the past four decades, with projections indicating a significant rise in the number of affected individuals by 2045. Therapeutic interventions in T2DM aim to control blood glucose levels and reduce the risk of complications. Dietary and lifestyle modifications play a crucial role in the management of T2DM and obesity. While conventional medical nutritional therapy (MNT) often promotes a high-carbohydrate, low-fat Mediterranean diet as an elective treatment, low-carbohydrate diets (LCDs), specifically those restricting carbohydrate intake to less than 130 g/day, have gained popularity due to their multifaceted benefits. Scientific research supports the efficacy of LCDs in improving glycemic control, weight loss, blood pressure, lipid profiles, and overall quality of life. However, sustaining these benefits over the long term remains challenging. This trial aimed to compare the effects of a Mediterranean diet vs. a low-carbohydrate diet (carbohydrate intake < 130 g/day) on overweight/obese patients with T2DM over a 16-week period. The study will evaluate the differential effects of these diets on glycemic regulation, weight reduction, lipid profile, and cardiovascular risk factors.
Methods:
The study population comprises 100 overweight/obese patients with poorly controlled T2DM. Anthropometric measurements, bioimpedance analysis, and blood chemistry assessments will be conducted at baseline and after the 16-week intervention period. Both dietary interventions were hypocaloric, with a focus on maintaining a 500 kcal/day energy deficit.
Results:
After 16 weeks, both diets had positive effects on various parameters, including weight loss, blood pressure, glucose control, lipid profile, and renal function. However, the low-carbohydrate diet appears to result in a greater reduction in BMI, blood pressure, waist circumference, glucose levels, lipid profiles, cardiovascular risk, renal markers, and overall metabolic parameters compared to the Mediterranean diet at the 16-week follow up.
Conclusions:
These findings suggest that a low-carbohydrate diet may be more effective than a Mediterranean diet in promoting weight loss and improving various metabolic and cardiovascular risk factors in overweight/obese patients with T2DM. However, it is important to note that further research is needed to understand the clinical implications and long-term sustainability of these findings.
... Therefore, lifestyle modifications, including calorie-restricted diets, are suggested as the firstchoice treatment for obesity management (7,8). Some pieces of evidence, however, suggest that variations in dietary macronutrient composition, independent of energy intake, may favorably affect body weight (9)(10)(11). ...
Introduction
Carbohydrate-restricted diets are one of the most effective dietary interventions for weight loss. However, the optimum carbohydrate intake for implementing the most effective weight-loss interventions is still being discussed. We aimed to determine the optimum carbohydrate intake for short- and long-term weight loss in adults with overweight and obesity.
Methods
We searched PubMed, Scopus, Web of Science, and CENTRAL from inception to May 2021 for randomized controlled trials examining the effect of a carbohydrate-restricted diet (≤45% of energy intake) as compared to a control diet (carbohydrate intake >45% of energy intake) on body weight in adults with overweight/obesity. A random-effects dose–response meta-analysis was conducted to calculate the mean difference for each 10% decrease in carbohydrate intake at the 6-month follow-up (1 to 6 months), 12-month follow-up (6 to 12 months), and follow-up longer than 12 months. The shape of the dose-dependent effects was also evaluated. The certainty of the evidence was rated using the GRADE approach. The minimal clinically important difference (MCID) threshold was defined as 5% weight loss (equal to 4.39 kg).
Results
A total of 110 trials were selected for the present meta-analysis. In the linear dose–response meta-analysis, each 10% decrease in carbohydrate intake reduced body weight by 0.64 kg (95% CI: −0.79 to −0.49; n = 101 trials with 4,135 participants, high-certainty evidence) at the 6-month follow-up and by 1.15 kg (95% CI: −1.61 to −0.69; 42 trials with 2,657 participants, moderate-certainty evidence) at the 12-month follow-up. Non-linear dose–response meta-analyses indicated a monotonic reduction in body weight with the decrease in carbohydrate intake, with the greatest reduction at 5% at the 6-month follow-up (mean difference 5%: −3.96 kg, 95% CI: −4.92 to −3.00) and 10% at the 12-month follow-up (mean difference 10%: −6.26 kg, 95% CI: −10.42 to −2.10). At follow-up longer than 12 months, dose–response analyses suggested a non-linear effect, wherein carbohydrate intakes higher than 40% and lower than 30% were not effective for weight loss.
Discussion
Carbohydrate restriction is an effective dietary strategy for important weight loss in adults with overweight and obesity. At 6-month and 12-month follow-ups, body weight decreased proportionally, more than the MCID threshold, along with the decrease in carbohydrate intake. At follow-up longer than 12 months, there was a non-linear effect, with the greatest reduction at 30% carbohydrate intake.
Systematic review registration
https://www.crd.york.ac.uk/prospero/, identifier CRD42022315042.
... 25-day ketogenic diet adherence in individuals with severe obesity resulted in significantly larger excess body weight loss and a greater reduction in γ-glutamyl transferase in males (66) . This greater benefit in males has been reported by others (67,68) . ...
Diets and dietary constituents that we consume have a considerable impact on disease risk. Intriguingly these effects may be modulated to some extent by sex. Lack of female representation in nutritional studies as well as a lack of stratification by sex has and continues to limit our understanding of these sex × diet interactions. Here we provide an overview of the current and available literature describing how exposure to certain dietary patterns (Western-style diet, Mediterranean diet, vegetarian/vegan, ketogenic diet) and dietary constituents (dietary fibre, PUFA and plant bioactive) influences disease risk in a sex-specific manner. Interestingly, these sex differences appear to be highly disease-specific. The identification of such sex differences in response to diet stresses the importance of sex stratification in nutritional research.
... Nonenergy restricted KDs have been shown to lead to a modest reduction in body weight, while retaining FFM, in individuals with a normal weight [20], and in physically active populations [21,22]. Volek et al. [23] reported that an energy-restricted KD induced a greater FM loss compared with an isocaloric low-fat diet, with preservation of lean tissue in individuals with obesity. Even though the latest studies have not accounted for loss of body water following KD, Gomez-Arbelaez et al. [24] showed that an energy-restricted KD leads to a substantial amount of weight loss with lean tissue preservation (~1 kg FFM loss in 20 kg weight loss), independently of the method used for body composition analysis (dual-energy x-ray absorptiometry, bioimpedance, or air-displacement plethysmography). ...
Background:
Early studies show that ketogenic diets (KDs) lead to preferential loss of fat mass (FM), while preserving fat-free mass (FFM). Additionally, animal data supports the anticatabolic effects of DL-3-hydroxybutyrate. From our knowledge a potential association between ß-hydroxybutyrate (ßHB) plasma concentrations and changes in body composition has never been explored.
Objective:
The main aim of this analysis was to determine if ßHB plasma concentrations, following hypocaloric KDs, were associated with FM and FFM changes in men and women with obesity.
Methods:
Data from 199 individuals (BMI= 36.6±4.3 kg/m2; age= 43.6±9.8 years; 82 men) were collated from three weight loss studies employing common measures of body composition (air displacement plethysmography) and ßHB plasma concentration (ELISA). The association between ßHB and weight, FM and FFM loss (kg), and %FFM loss (%FFML) was investigated with Spearman correlation. Multivariable linear regression was used to determine if ßHB was a significant predictor of the changes in anthropometric variables, after adjusting for confounding factors.
Results:
ßHB was not associated with FFML (% or kg), but a weak positive association was seen with FM loss (r=0.182, P=0.01, n=199) and a trend with weight loss (r=0.128, P=0.072, n=199). ßHB was a significant predictor of both weight and FM loss (kg), after adjusting for age, sex, baseline BMI, and intervention study.
Conclusion:
The magnitude of ketosis is not associated with FFM preservation. However, the higher the level of ketosis, the greater the weight and FM loss. Further studies are needed to confirm these findings and to explore the mechanisms involved.
Clinical trial registration:
ClinicalTrials.gov identifier: NCT01834859, NCT04051190, NCT02944253.
... In order to promote diet-induced ketosis, KDs are high in fat and low in carbohydrate content and have been demonstrated to reduce body weight and improve metabolic outcomes in rodents and humans [27][28][29]. In this study, KD exposure began after 9 weeks on HFD. ...
Background: Raspberry ketone (RK: [4-(4-Hydroxyphenyl)-2-butanone]) is a dietary supplement marketed for weight control. RK is structurally unrelated to the ketone bodies elevated with a ketogenic diet (KD). This study aims to determine whether RK oral supplementation with KD improves the weight loss outcomes in high-fat diet (HFD; 45% fat)-fed mice. Methods: Male and female C57BL/6J mice were HFD-fed for 9 weeks and switched to KD (80% fat) or a control diet (CD; 10% fat) or continued with the HFD for 4 weeks. Coincident with the diet switch, each diet group received oral RK (200 mg/kg/day) or a vehicle. Results: In male KD-fed mice, oral RK reduced body weight by ~6% (KD_Veh: −9.2 ± 1% vs. KD_RK: −15.1 ± 1%) and fat composition by ~18% (KD_Veh: −16.0 ± 4% vs. KD_RK: −34.2 ± 5%). HFD and KD feeding induced glucose intolerance in both male and female mice. Oral RK decreased the glucose area under the curve in female mice by ~6% (KD_Veh: 44,877 ± 957 vs. KD_RK: 42,040 ± 675 mg*min/dl). KD also had gut microbiota alterations with higher alpha diversity in males and more beta diversity with RK. These findings suggest sex-specific weight loss effects with RK and KD in mice.
... In contrast, a low-carbohydrate diet lowers insulin levels, thus reducing fat synthesis and stimulating lipolysis, which nullify the effects of high dietary fat intake. These factors may explain why low-carbohydrate diets tend to work well for visceral fat reduction [16][17][18] . ...
The fundamental cause of obesity is widely assumed to be an energy imbalance between calories consumed and calories expended (i.e., the energy balance theory). However, this century-old obesity paradigm is fallacious. According to known laws of physics, the actual etiology of obesity is chronic positive mass balance, not positive energy balance. Furthermore, the relevant physical law in body mass regulation is the Law of Conservation of Mass, not the Law of Conservation of Energy. It is important to understand that energy balance and mass balance are separate balances in the human body. Since calories simply represent the heat released on food oxidation, they have no impact on body mass. Body mass can only change as a result of net mass flow; thus, the only food property that can augment body mass is its nutrient mass, not its energy content. The recently proposed mass balance model describes the temporal evolution of body weight and body composition under a wide variety of feeding experiments, and it seems to provide a highly accurate description of the very best experimental human feeding data. By shifting to a mass balance paradigm of obesity, a deeper understanding of this condition may follow in the near future. The purpose of this living review is to present the core issues of the upcoming paradigm shift and some practical applications related to the subject.
... In contrast, a low-carbohydrate diet lowers insulin levels, reducing fat synthesis and stimulating lipolysis, which nullifies the effects of high dietary fat intake. These factors may explain why low-carbohydrate diets tend to work well for visceral fat reduction [e.g.,15,17,56].Recently,Goss et al. reported that in their eight-week study the very-low-carbohydrate/high-fat diet group experienced 3-fold greater loss of visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) when compared to the high-carbohydrate/low-fat diet group ...
It is widely assumed that the fundamental cause of obesity is an energy imbalance between calories consumed and calories expended (i.e., the energy balance theory; EBT). However, this century-old obesity paradigm must be fallacious. According to known laws of physics, chronic positive mass balance is the actual etiology of obesity, not positive energy balance. The relevant physical law in terms of body mass regulation is the Law of Conservation of Mass, not the Law of Conservation of Energy. It is important to understand that energy balance and mass balance are separate balances in the human body. Calories represent the heat release upon food oxidation, and as such, calories have no impact on body mass. Body mass can only change due to net mass flow; thus, the only food property that can augment body mass is its nutrient mass, not its energy content. A recently proposed mass balance model (MBM) describes the temporal evolution of body weight and body composition under a wide variety of feeding experiments, and it seems to provide a highly accurate description of the very best experimental human feeding data. By shifting to a mass balance paradigm of obesity, a deeper understanding of this disease may follow in the near future. The purpose of this living review is to present the core issues of the upcoming paradigm shift as well as some practical applications related to the topic.
... This should be carefully evaluated in the future, as it suggests that in women, mitochondrial function is reduced after CR through limitation of mitochondrial lipid oxidation. This can mechanistically explain the observation that women have a blunted weight loss compared with men in response to CR, especially in response to lowcarbohydrate diets [2,77]. ...
Objective
We performed a meta-analysis to determine the changes induced by calorie restriction (CR) and bariatric surgery on human skeletal muscle mitochondria.
Methods
A systematic search of Medline and Web of Science was conducted. Controlled trials exploring CR (≥14 days) and mitochondrial function and/or content assessment were included. Moreover, studies analyzing weight loss following gastric surgery were included for comparison purposes. Human muscle data from 28 studies assessing CR (520 muscle samples) and from 10 studies assessing bariatric surgery (155 muscle samples) were analyzed in a random effect meta-analysis with three a priori chosen covariates.
Main results
We report a decrease (p < 0.05) (mean (95 % CI)) in maximal mitochondrial state 3 respiration in response to CR (−0.44 (−0.85, −0.03)) but not in response to surgery (−0.33 (−1.18, 0.52)). No changes in mitochondrial content were reported after CR (−0.05 (−0.12, 0.13)) or in response to surgery (0.23 (−0.05, 0.52)). Moreover, data from CR subjects showed a reduction in complex IV (CIV) activity (−0.29 (−0.56, −0.03)) but not in CIV content (−0.21 (−0.63, 0.22)). Similar results were obtained when the length of the protocol, the initial body mass index, and the estimated energy deficit were included in the model as covariates.
Conclusion
The observation of reduced maximal mitochondrial state 3, uncoupled respiration, and CIV activity without altering mitochondrial content suggests that, in human skeletal muscle, CR mainly modulates intrinsic mitochondrial function.
... reducing fat synthesis and stimulating lipolysis, which nullifies the effects of high dietary fat intake. These factors may explain why low-carbohydrate diets tend to work well for visceral fat reduction [e.g.,15,17].Recently, Goss et al. reported that in their eight-week study the very-low-carbohydrate/high-fat diet group experienced 3-fold greater loss of visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) when compared to the high-carbohydrate/low-fat diet group[17]. Following the very-low-carbohydrate/high-fat diet, there was a drastically greater decrease in fasting insulin compared to the high-carbohydrate/low-fat diet (13.7 ± 5.6 → 9.4 ± 4.0 vs. 15.6 ± 6.5 → ...
According to known laws of physics, chronic positive mass balance is the actual etiology of obesity, not positive energy balance. The relevant physical law in terms of body mass regulation is the Law of Conservation of Mass, not the Law of Conservation of Energy. It is important to understand that energy balance and mass balance are separate balances in the human body. Calories represent the heat release upon food oxidation, and as such, calories have no impact on body mass. Body mass can only change due to net mass flow; thus, the only food property that can augment body mass is its nutrient mass, not its energy content. A recently proposed mass balance model (MBM) describes the temporal evolution of body weight and body composition under a wide variety of feeding experiments, and it seems to provide a highly accurate description of the very best experimental human feeding data. By shifting to a mass balance paradigm of obesity, a deeper understanding of this disease may follow in the near future. The purpose of this living review is to present the core issues of the upcoming paradigm shift as well as some practical applications related to the topic.
