Nicholas A. Burd

University of Illinois, Urbana-Champaign | UIUC · Department of Kinesiology and Community Health

Microbial protease co-ingestion with pea protein increased postprandial plasma total amino acid concentrations across 5 hours compared to placebo in health adults, as well as increasing branched chain, essential, and total amino acid availability in the early postprandial period (0‒2 hours). Future studies are warranted to investigate the metabolic...

While protein intake augments resistance training–induced changes in muscular strength and body composition, the benefits of higher protein intake and resistance training on cognitive outcomes and myokines with neurocognitive implications are unclear. The objective of this study is to compare the efficacy of moderate (0.8–1.0 g·kg⁻¹·day⁻¹) and high...

Feeding and resistance exercise stimulate myofibrillar protein synthesis rates (MPS) in healthy adults. This anabolic characterization of 'healthy adults' has been namely focused on males. Therefore, the purpose of this study was to examine the temporal responses of MPS and anabolic signaling to resistance exercise alone or combined with the ingest...

Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of literature surrounding the effects of essential amino acid (EAA) supplementation on skeletal muscle maintenance and performance. This position stand is intended to provide a scientific foundation to athletes, dietitians...

Background: Digestive enzymes are commonly consumed with food to improve macronutrient digestion and support gastrointestinal comfort. Dietary supplementation with microbial proteases, in particular, is an underutilized approach to enhance dietary protein digestion and postprandial blood amino acid (AA) concentrations. No studies to date have inves...

Purpose: Several factors affect muscle protein synthesis (MPS) in the post-absorptive state. Extreme physical inactivity (e.g., bedrest) may reduce basal MPS, whereas walking may augment basal MPS. We hypothesized that Outpatients would have a higher postabsorptive MPS than Inpatients. Methods: To test this hypothesis, we conducted a retrospecti...

The effects of following the Mediterranean-Dietary Approaches to Stop Hypertension (DASH) Intervention for Neurodegenerative Delay (MIND) diet on metabolic health remains understudied. This cross-sectional analysis of 163 adults investigated associations between adherence to the MIND, Mediterranean, DASH, and Healthy Eating Index (HEI-2015) diets a...

As the global population ages, the prevalence of cognitive decline and dementia is expected to rise, creating a significant health and economic burden. The purpose of this trial is to rigorously test, for the first time, the efficacy of yoga training as a physical activity intervention to mitigate age-related cognitive decline and impairment. We ar...

Background: Protein is most commonly consumed as whole foods as opposed to single nutrients. However, the food matrix regulation of the postprandial muscle protein synthetic response has received little attention. Objectives: The purpose of this study was to assess the effects of eating salmon (SAL) and of ingesting the same nutrients as an isol...

Background: Consuming adequate dietary fiber is a promising strategy for reducing systemic inflammation. Objective: To evaluate relationships between dietary fiber intake, markers of metabolic endotoxemia, and systemic inflammation in adults. Methods: This was a cross-sectional study of 129 healthy participants (age 33.6 ± 6.1 years, BMI 30.5...

This paper examines the opinion that we should aim to optimize, rather than maximize, protein intakes to avoid over-emphasizing muscle-centric protein requirements. An optimal eating approach strives to minimize amino acid oxidative waste and more efficiently stimulate postprandial muscle protein accretion. To do this, practitioners should acknowle...

Purpose: We aimed to assess whether total daily physical activity (PA), PA intensities, sedentary time (ST) and prolonged ST are associated with differences in the gut microbiota composition or short-chain fatty acid (SCFA) profile of adults with overweight or obesity. Methods: Cross-sectional associations between total daily PA (counts per minu...

The activation of the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, by anabolic stimuli (such as muscle contraction or essential amino acids) involves its translocation to the cell periphery. Leucine is generally considered the most anabolic of amino acids for its ability to independently modulate musc...

Previous work has demonstrated that physical activity and weight status are associated with attentional inhibition (indexed with the P3 component of event-related potentials). However, there is limited knowledge on the neural underpinnings of motor response planning and activation. This study investigated the effect of weight status on relationship...

Resistance training combined with adequate protein intake supports skeletal muscle strength and hypertrophy. These adaptations are supported by the action of muscle stem cells (MuSCs) which are regulated, in part, by fibro-adipogenic progenitors (FAPs) and circulating factors delivered through capillaries. It is unclear if middle-aged males and fem...

Background Most previous work has focused on a single-nutrient, bottom-up approach when examining the influence of diet on neurocognition. Thus, the impact of dietary patterns on cognitive health is under-investigated. Objectives We aimed to investigate the relationship between different diet indices (i.e., Mediterranean, Dietary Approaches to Sto...

Creatine (Cr) supplementation is a well-established strategy to enhance gains in strength, lean body mass, and power from a period of resistance training. However, the effectiveness of creatyl-L-leucine (CLL), a purported Cr amide, is unknown. Therefore, the purpose of this study was to assess the effects of CLL on muscle Cr content. Twenty-nine he...

Background Egg protein is ingested during recovery from exercise to facilitate the post-exercise increase in muscle protein synthesis rates and, as such, to support the skeletal muscle adaptive response to exercise training. The impact of cooking egg protein on post-exercise muscle protein synthesis is unknown. Objectives To compare the impact of...

Satellite cells are required for muscle regeneration, remodeling, and repair through their activation, proliferation, and differentiation; however, how dietary factors regulate this process remains poorly understood. The L-Type amino acid transporter 1 (LAT1) transports amino acids, such as leucine, into mature myofibers, which then stimulates prot...

Skeletal muscle aging is a multi-dimensional pathology of atrophy, reduced strength, and oxidative damage. While some molecular targets may mediate both hypertrophic and oxidative adaptations in muscle, their responsiveness in humans and relationship with functional outcomes like strength remain unclear. Promising therapeutic targets to combat musc...

Objectives To assess whether physical activity (PA) volume and intensities are associated with differences in the gut microbiota composition or short-chain fatty acid (SCFA) profile of adults with overweight or obesity. Methods PA data and fecal samples collected pre-intervention for the Persea americana for Total Health (PATH) study were used to...

Objectives Given that previous research has disproportionately focused on individual nutrients, knowledge of diet patterns and cognitive health is limited. Thus, we investigated the relationship between different diet indices (Mediterranean, Dietary Approaches to Stop Hypertension [DASH], Healthy-Eating-Index-2015 [HEI-2015], and Mediterranean-DASH...

Introduction: Prevalence of chronic hypohydration remains elevated among adults in the USA; however, the health effects of hypohydration in regards to human gut health have not been explored. Methods: This study examined the relationship between total water intake, hydration biomarkers (first-morning urine specific gravity [FMUsg], first-morning...

Although muscular strength has been linked to greater cognitive function across different cognitive domains, the mechanism(s) through which this occurs remain(s) poorly understood. Indeed, while an emerging body of literature suggests peripheral myokines released from muscular contractions may play a role in this relationship, additional research i...

Objective The goal of this investigation was to evaluate circulating and skeletal muscle inflammatory biomarkers between MHD and demographic-matched control subjects (CON) before and after ingestion of a protein rich meal. Design and Methods CON (n=8; 50±2 y; 31±1 kg/m²) and MHD patients (n=8; 56±5 y; 32±2 kg/m²) underwent a basal blood draw and m...

See corresponding article on page 2074. Approximately 1.55 million individuals globally receive routine hemodialysis to manage kidney failure, which costs up to 66.3 billion dollars annually (1). Hemodialysis serves to remove toxic uremic solutes from the body, yet patients have a high risk of mortality from other pathologies, including cardiovascu...

Leucine is regarded as an anabolic trigger for the mTORC1 pathway and the stimulation muscle protein synthesis rates. More recently, there has been an interest in underpinning the relevance of BCAA-containing dipeptides and their intact absorption into circulation to regulate muscle anabolic responses. We investigated the effects of dileucine and l...

Key points The ingestion of protein potentiates the stimulation of myofibrillar protein synthesis rates after an acute bout of resistance exercise. Protein supplementation (eating above the protein Recommended Dietary Allowance) during resistance training has been shown to maximize lean mass and strength gains in healthy young and older adults. Her...

Background Although intake of Hass avocado has been cross-sectionally linked to lower abdominal obesity, knowledge of the effects of avocado consumption on abdominal adiposity and glycemic outcomes remains limited. Objective The effects of avocado consumption on abdominal adiposity, insulin resistance, oral-glucose-tolerance test (OGTT), and estim...

Objectives The loss of muscle mass with age increases not only risk of functional impairment, but also development and exacerbation of cardiometabolic disease. While dietary protein intake and habitual resistance exercise are traditional strategies to offset age-related decrements in lean mass, it is important to define the role of other regulatory...

Objectives Dietary protein intake augments muscle protein synthesis rates during acute recovery from resistance exercise training (RET) and can help offset age-related loss in muscle mass. Skeletal muscle tissue contains a variety of different protein pools such as myofibrillar (contractile), mitochondrial (substrate oxidation), and collagen (struc...

Objectives The ingestion of free amino acids, or isolated sources of protein, results in faster postprandial release of dietary amino acids into circulation, which stimulates muscle protein synthesis rates. However, indirect evidence suggests that this rapid release of dietary amino acids after the ingestion of free amino acids is coupled with high...

Excessive sedentariness has been related to poorer cognitive control in adults. Sedentariness may compound obesity-related impairments in response inhibition, but its relationship to response inhibition remains poorly understood. This study investigated the relationship between accelerometer-measured sedentary time (ST, min/day), performance on the...

Estimating the individualized treatment effect has become one of the most popular topics in statistics and machine learning communities in recent years. Most existing methods focus on modeling the heterogeneous treatment effects for univariate outcomes. However, many biomedical studies are interested in studying multiple highly correlated endpoints...

Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately,...

To assess the relationships between daily sedentary time (ST), prolonged ST, moderate-to-vigorous physical activity (MVPA), and behavioral and neuroelectric indices of cognitive control in adults with overweight and obesity (OW/OB). A cross-sectional design was used. Overall, 89 adults (BMI = 31.9 ± 4.9 kg/m²) provided measures of ST, prolonged ST...

Elevated visceral adipose tissue (VAT) has been associated with cardiometabolic risk factors including chronic systemic low-grade inflammation. Whereas the cognitive implications of inflammation have been extensively studied in preclinical models, the influence of inflammatory cytokines on cognitive function in humans is unclear. This study aimed t...

Endurance athletes commonly experience lower gastrointestinal (GI) symptoms similar to those of irritable bowel syndrome (IBS). Previous research on the restriction of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), a diet-based mitigation strategy initially developed for IBS, has shown promise for application in...

Protein intake above the Recommended Dietary Allowance (RDA) and resistance training are known anabolic stimuli to support healthy aging. Specifically, protein supplementation after resistance exercise and nightly are strategies to maximize utilization of protein intake above the RDA in healthy adults. As such, the primary objective was to examine...

Background The xanthophyll carotenoids lutein+zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognitive function is sparse. Design 80 middle-aged adults with overweight and obesity (Body Mass Index: (BMI) ≥25.0 kg/m²), completed 7...

Skeletal muscle is a vital tissue for the maintenance of physical independence and quality of life across the lifespan. Skeletal muscle mass is regulated by net protein balance—the difference between muscle protein synthesis and muscle protein breakdown rates—and can be maximized by resistance exercise and consuming adequate amounts of high-quality...

Introduction: The effect of various types of dietary fat on cardiometabolic health continues to be debated, due in part to the high heterogeneity of results following clinical trials investigating the effects of saturated (SFA) and unsaturated fat intake. This variability may be due to genetic differences. Individuals with obesity are at an increa...

Key points Patients with renal failure undergoing maintenance haemodialysis are associated with insulin resistance and protein metabolism dysfunction. Novel research suggests that disruption to the transmembrane protein linkage between the cytoskeleton and the extracellular matrix in skeletal muscle may contribute to reduced amino acid metabolism a...

Strength is a vital component of healthy aging. However, “strength” comes in different forms (includes both physical and mental aspects) and can look different at various phases of adult life. Healthy eating and regular exercise are clearly important pillars for strength. This paper proposes a framework that underlines the value of protein foods an...

Background: Avocados are rich in dietary fiber and monounsaturated fatty acids (MUFAs), nutrients that have been independently connected to metabolic health benefits and the gastrointestinal microbiota. Objectives: We aimed to evaluate the impact of avocado consumption on the gastrointestinal microbiota and microbial metabolites, secondary outco...

Insulin resistance is a complex metabolic disorder implicated in the development of many chronic diseases. While it is generally accepted that body mass loss should be the primary approach for the management of insulin resistance-related disorders in overweight and obese individuals, there is no consensus among researchers regarding optimal protein...

Objectives Lutein and zeaxanthin are xanthophyll carotenoids that comprise macular pigment in the eye and disproportionately accumulate in brain tissue. While the link between serum xanthophylls and macular pigment has received considerable investigation, comparatively less is known regarding the relationship between circulating xanthophylls and re...

Objectives Apelin is a putative exercise-sensitive myokine that has been shown to be associated with physical independence during aging. Physical performance is highly dependent on muscle strength, with a clear role of dietary protein (i.e., > Recommended Dietary Allowance) for the maintenance of age-related muscle strength. However, the influence...

Objectives Yes-Associated Protein (YAP) is implicated as a regulator of the post-exercise skeletal muscle response through mechanical transduction. We recently observed that resistance exercise (RE) increased both total (t) and phosphorylated (p) muscle YAP content, which correlated with extracellular signal-regulated kinase 1/2 (Erk1/2). Other ana...

Objectives Consumption and biomarker status of the xanthophyll-carotenoids lutein + zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognition is sparse. We examined associations between dietary and bio-markers of lutein + zeaxanthi...

Objectives Healthy eating patterns consist of eating whole foods as opposed to single nutrients. The maintenance of skeletal muscle mass is of particular interest to overall health. As such, there is a need to underpin the role of eating nutrients within their natural whole-food matrix versus isolated nutrients on the regulation of postprandial mus...

Background: Avocados are rich in unsaturated fat and fiber; clinical trials have investigated their effects on metabolic disease. There is high variability in individual changes following avocado consumption, which may be in part due to individual genetic differences. Objective: Secondary analyses of the Persea americana for Total Health (PATH)...

Background: Dietary protein ingestion stimulates muscle protein synthesis by providing amino acids to the muscle. The magnitude and duration of the postprandial increase in muscle protein synthesis rates are largely determined by dietary protein digestion and amino acid absorption kinetics. Objective: We assessed the impact of protein type, prot...

Background: Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), the most common bariatric surgeries performed worldwide, increase the risk to develop an alcohol use disorder. This might be due, in part, to surgery-related changes in alcohol pharmacokinetics. Another risk factor, unexplored within this population, is having a reduced subje...

Objectives: Excess adiposity increases risk for cognitive impairment. Consumption of avocado, a highly bioavailable source of the xanthophyll lutein, has been shown to improve retinal lutein accumulation and cognitive function. Thus, we evaluated the influence of avocado consumption on cognitive function and lutein status among adults with overwei...

The anabolic action of 'fast' whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. We assessed the time course of anabolic signaling activation and stimulation of myofibrillar protein synthesis rates (MPS) after ingestion of a food source that represents a more typic...

During a traditional set configuration of resistance exercise (TRD), characterized by a continuous completion of repetitions, a decrease in power output tends to occur throughout a set of repetitions. Inclusion of intra-set rest, otherwise known as a cluster set configuration (CLU), counteracts this power decline. However, the effect of a CLU confi...

Carbohydrate (CHO) ingestion is an established strategy to improve endurance performance. Race fuels should not only sustain performance, but also be readily digested and absorbed. Potatoes are a whole-food based option that fulfills these criteria yet their impact on performance remains unexamined. We investigated the effects of potato purée inges...

Background: We have recently shown that a novel signalling kinase, inositol hexakisphosphate kinase 1 (IP6K1), is implicated in whole-body insulin resistance via its inhibitory action on Akt. Insulin and insulin like growth factor 1 (IGF-1) share many intracellular processes with both known to play a key role in glucose and protein metabolism in s...

Sarcopenia is defined as the combined loss of skeletal muscle strength, function, and/or mass with aging. This degenerative loss of muscle mass is associated with poor quality of life and early mortality humans. The loss of muscle mass occurs due to acute changes in daily muscle net protein balance (NPB). It is generally believed a poor NPB occurs...

The intrinsically labeled protein approach is the preferred method to quantify the release of dietary protein-derived amino acids into the circulation

Skeletal muscle mass, a strong predictor of longevity and health in humans, is determined by the balance of two cellular processes, muscle protein synthesis (MPS) and muscle protein breakdown (MPB). Of these two, MPS seems to be particularly sensitive to changes in mechanical load and/or nutritional status, and therefore much research has focused o...

Utilizing Cluster vs Traditional sets elicits differences in overall power and muscle protein synthesis, independent of mTOR activation.

Improving the health of skeletal muscle is an important component of obesity treatment. Apart from allowing for physical activity, skeletal muscle tissue is fundamental for the regulation of postprandial macronutrient metabolism, a time period that represents when metabolic derangements are most often observed in adults with obesity. In order for s...

A healthy eating pattern, regardless of age, should consist of ingesting high quality protein preferably in adequate amounts across all meals throughout the day. Of particular relevance to overall health is the growth, development, and maintenance of skeletal muscle tissue. Skeletal muscle not only contributes to physical strength and performance,...

Background Resistance exercise and dietary protein stimulate muscle protein synthesis (MPS). The rate at which proteins are digested and absorbed into circulation alters peak plasma amino acid concentrations and may modulate postexercise MPS. A novel mineral modified milk protein concentrate (mMPC), with identical amino acid composition to standar...

Objectives: There is substantial controversy regarding the role of saturated (SFA) and unsaturated fat intake for optimal cardiometabolic health due to the heterogeneity of blood lipid changes in clinical trials. This variance may be due to genetic differences. Studying physiologically relevant variants can elucidate the mechanisms between genotyp...

Objectives: Lutein is a carotenoid found in green leafy vegetables, avocados, and eggs, and is purported to have protective effects against age-related macular degeneration (AMD) as well as benefits for visual and cognitive health. Recent studies have indicated significant variation in serum lutein among individuals and that gastrointestinal (GI)...

Objectives: A converging body of evidence indicates elevated weight status is inversely related to memory forms that disproportionately rely on the hippocampus. However, much of this work has relied on BMI, resulting in a limited understanding of the impact of body composition on memory performance. Accordingly, this study investigated the influen...

Objectives: Over 35% of adults have elevated abdominal obesity. This is concerning because abdominal obesity increases risk for type 2 diabetes. Therefore, dietary interventions with the potential to prevent abdominal obesity and its metabolic consequences have gained increasing importance. Habitual intake of the Hass avocado (Persea Americana) ha...

Objectives: Excess fat mass has been associated with poorer cognitive function. Elevated visceral adiposity (VAT) has also been associated with cardiometabolic risk factors including chronic systemic low-grade inflammation. Whereas the cognitive implications of inflammation have been extensively studied in preclinical models, the influence of infl...

Objectives: Carbohydrate (CHO) ingestion is an established nutritional strategy to improve endurance performance, yet currently available products may contribute to gastrointestinal (GI) distress. Potatoes have a high-glycemic index, indicating that their CHO content is readily available. We aimed to compare the effects of ingesting potato purée (...

Objectives: Overweight and obesity affect over two-thirds of the US population. This is concerning, as excess adiposity increases risk for dementia in later life. Thus, it is important to elucidate dietary approaches that benefit cognition. Lutein is a xanthophyll carotenoid thought to impact cognitive function. Daily consumption of avocado has be...

Objectives High protein diets (>1.6 g/kg/d) are thought to maximize daily myofibrillar protein synthesis (MPS) rates to resistance exercise training. Current research has focused on isolated protein sources to stimulate MPS disregarding other nutritional factors within a healthy diet. Therefore, we examined the impact of dietary counseling underlin...

Often described as ‘nature’s perfect food’, perceptions of egg consumption and human health have evolved substantially over the past decades, in particular dietary guidelines no longer include a limit for dietary cholesterol and recommend eggs as part of healthy eating patterns. This book presents the opportunities for processing eggs to produce va...

Dietary carotenoids, plant pigments with anti-oxidant properties, accumulate in neural tissue and are often found in lower concentrations among individuals with obesity. Given previous evidence of negative associations between excess adiposity and memory, it is possible that greater carotenoid status may confer neuroprotective effects among persons...

Skeletal muscle loss is the most important hallmark of protein energy wasting syndrome as it contributes to declines in physical independence, poor quality of life, and higher mortality risk in individuals with ESRD on maintenance hemodialysis (HD). As such, exercise and nutritional interventions have been investigated with the goal to preserve ske...