Effects of dietary protein intake on body composition changes after weight loss in older adults: a systematic review and meta-analysis

Enhanced protein intake on maintaining muscle mass, strength, and physical function in adults with overweight/obesity: A systematic review and meta-analysis

BACKGROUND & AIMS

Weight loss in individuals with obesity and overweight leads to metabolic and health benefits but also poses the risk of muscle mass reduction. This systematic review and meta-analysis of randomized controlled trials aims to determine the initial protein amount necessary for achieving weight loss while maintaining muscle mass, strength, and physical function in adults with overweight and obesity.

METHODS

Relevant literature databases, including Medical Literature Analysis and Retrieval System Online (Medline), Excerpta Medica (Embase), the Cumulative Index to Nursing and Allied Health Literature (CINHAL), and Web of Science, were electronically searched up to 15 March 2023. We examined the effect of additional protein intake on muscle mass, strength, and physical function in adults with overweight or obesity targeting weight loss. The risk of bias was assessed using the Cochrane RoB 2.0 tool. Results were synthesized using standardized mean differences (SMD) and 95% confidence intervals (CI) via a random-effects model.

RESULTS

Forty-seven studies (n = 3218) were included. In the muscle mass analysis, twenty-eight trials with 1989 participants were encompassed. Results indicated that increased protein intake significantly prevents muscle mass decline in adults with overweight or obesity aiming for weight loss (SMD 0.75; 95% CI 0.41 to 1.10; p < 0.001). Enhanced protein intake did not significantly prevent decreases in muscle strength and physical function. An intake exceeding 1.3 g/kg/day is anticipated to increase muscle mass, while an intake below 1.0 g/kg/day is associated with a higher risk of muscle mass decline. The risk of bias in studies regarding muscle mass ranged from low to high.

CONCLUSIONS

Adults with overweight or obesity and aim for weight loss can more effectively retain muscle mass through higher protein intake, as opposed to no protein intake enhancement.

Glucagon-like peptide-1 receptor agonist-based agents and weight loss composition: Filling the gaps

Excess adiposity is at the root of type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as first-line treatments for T2D based on significant weight loss results. The composition of weight loss using most diets consists of <25% fat-free mass (FFM) loss, with the remainder from fat stores. Higher amounts of weight loss (achieved with metabolic bariatric surgery) result in greater reductions in FFM. Our aim was to assess the impact that GLP-1RA-based treatments have on FFM. We analysed studies that reported changes in FFM with the following agents: exenatide, liraglutide, semaglutide, and the dual incretin receptor agonist tirzepatide. We performed an analysis of various weight loss interventions to provide a reference for expected changes in FFM. We evaluated studies using dual-energy X-ray absorptiometry (DXA) for measuring FFM (a crude surrogate for skeletal muscle). In evaluating the composition of weight loss, the percentage lost as fat-free mass (%FFML) was equal to ΔFFM/total weight change. The %FFML using GLP-1RA-based agents was between 20% and 40%. In the 28 clinical trials evaluated, the proportion of FFM loss was highly variable, but the majority reported %FFML exceeding 25%. Our review was limited to small substudies and the use of DXA, which does not measure skeletal muscle mass directly. Since FFM contains a variable amount of muscle (approximately 55%), this indirect measure may explain the heterogeneity in the data. Assessing quantity and quality of skeletal muscle using advanced imaging (magnetic resonance imaging) with functional testing will help fill the gaps in our current understanding.

Fundamental Body Composition Principles Provide Context for Fat-Free and Skeletal Muscle Loss With GLP-1 RA Treatments

During weight loss, reductions in body mass are commonly described using molecular body components (eg, fat mass and fat-free mass [FFM]) or tissues and organs (eg, adipose tissue and skeletal muscle). While often conflated, distinctions between body components established by different levels of the 5-level model of body composition-which partitions body mass according to the atomic, molecular, cellular, tissue/organ, or whole-body level-are essential to recall when interpreting the composition of weight loss. A contemporary area of clinical and research interest that demonstrates the importance of these concepts is the discussion surrounding body composition changes with glucagon-like peptide-1 receptor agonists (GLP-1RA), particularly in regard to changes in FFM and skeletal muscle mass. The present article emphasizes the importance of fundamental principles when interpreting body composition changes experienced during weight loss, with a particular focus on GLP-1RA drug trials. The potential for obligatory loss of FFM due to reductions in adipose tissue mass and distribution of FFM loss from distinct body tissues are also discussed. Finally, selected countermeasures to combat loss of FFM and skeletal muscle, namely resistance exercise training and increased protein intake, are presented. Collectively, these considerations may allow for enhanced clarity when conceptualizing, discussing, and seeking to influence body composition changes experienced during weight loss.

Nutrition Practices of Lithuanian Elite International and National-level Male Bodybuilders in the Pre-competition Period

OBJECTIVES

To compare the pre-competition nutrition practices of Lithuanian elite international-level (IL) and national-level (NL) bodybuilders.

METHODS

Sixteen male bodybuilders (n=8 per group) were enrolled. The IL group comprised individuals achieving 1st to 4th place in the World and European Championships organized by the IFBB, whereas the NL group ranked between 1st and 6th place in the national championships. Body mass and diet data were obtained via a questionnaire. A repeated-measures ANOVA was performed using time as a within factor and group as a between factor.

RESULTS

Both groups experienced a reduction in body mass during the pre-competition phase (p<0.001), which was slower in the IL than in the NL group (p=0.048). Both groups exhibited a reduction in caloric (p<0.001), carbohydrate (p<0.001), and fat (p=0.006) intake relative to body mass, but not in protein intake. Nevertheless, the IL group had a higher intake of calories (p=0.015), protein (p<0.001), but not carbohydrates relative to body mass vs. the NL group.

CONCLUSIONS

The Lithuanian IL and NL bodybuilders both reduced calories by cutting fat and carbohydrates during pre-competition. The IL group maintained higher calorie and protein intake, resulting in similar body mass loss but at a slower rate than the NL group.

Changes in lean body mass with glucagon-like peptide-1-based therapies and mitigation strategies

Weight loss induced by glucagon-like peptide-1 receptor agonists (GLP-1RAs) and dual glucagon-like peptide-1 receptor (GLP-1R)/glucose-dependent insulinotropic polypeptide receptor agonists is coming closer to the magnitudes achieved with surgery. However, with greater weight loss there is concern about potential side effects on muscle quantity (mass), health and function. There is heterogeneity in the reported effects of GLP-1-based therapies on lean mass changes in clinical trials: in some studies, reductions in lean mass range between 40% and 60% as a proportion of total weight lost, while other studies show lean mass reductions of approximately 15% or less of total weight lost. There are several potential reasons underlying this heterogeneity, including population, drug-specific/molecular, and comorbidity effects. Furthermore, changes in lean mass may not always reflect changes in muscle mass as the former measure includes not only muscle but also organs, bone, fluids, and water in fat tissue. Based on contemporary evidence with the addition of magnetic resonance imaging-based studies, skeletal muscle changes with GLP-1RA treatments appear to be adaptive: reductions in muscle volume seem to be commensurate with what is expected given ageing, disease status, and weight loss achieved, and the improvement in insulin sensitivity and muscle fat infiltration likely contributes to an adaptive process with improved muscle quality, lowering the probability for loss in strength and function. Nevertheless, factors such as older age and severity of disease may influence the selection of appropriate candidates for these therapies due to risk of sarcopenia. To further improve muscle health during weight loss, several pharmacological treatments to maintain or improve muscle mass designed in combination with GLP-1-based therapies are under development. Future research on GLP-1-based and other therapies designed for weight loss should focus on more accurate and meaningful assessments of muscle mass, composition, as well as function, mobility or strength, to better define their impact on muscle health for the substantial number of patients who will likely be taking these medications well into the future.

Medical weight loss in older persons with obesity

The prevalence of individuals with obesity or overweight has steadily increased over the past decades both worldwide, and in the United States. This trend is also evident in the older adult population, which has experienced a continuous rise in the number of individuals with overweight or obesity. This is relevant due to the impact of obesity in older adults' quality of life, physical function, morbidity, and healthcare costs. This review aims to provide practical guidance and currently available approaches for healthcare professionals in managing this population. Both non-pharmacological methods such as intensive behavioural therapy, nutritional interventions, and physical activity, as well as anti-obesity medications, are discussed, with a focus on their potential positive and negative effects in older adults. Additionally, bariatric therapy is evaluated, including current procedures available and the associated results and risks in the older population.

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn's disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the 'gut-muscle axis' hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition.

Quantification and interpretation of postprandial whole-body protein metabolism using stable isotope methodology: a narrative review

Stable isotopes are routinely applied to determine the impact of factors such as aging, disease, exercise, and feeding on whole-body protein metabolism. The most common approaches to quantify whole-body protein synthesis, breakdown, and oxidation rates and net protein balance are based on the quantification of plasma amino acid kinetics. In the postabsorptive state, plasma amino acid kinetics can easily be assessed using a constant infusion of one or more stable isotope labeled amino acid tracers. In the postprandial state, there is an exogenous, dietary protein-derived amino acid flux that needs to be accounted for. To accurately quantify both endogenous as well as exogenous (protein-derived) amino acid release in the circulation, the continuous tracer infusion method should be accompanied by the ingestion of intrinsically labeled protein. However, the production of labeled protein is too expensive and labor intensive for use in more routine research studies. Alternative approaches have either assumed that 100% of exogenous amino acids are released in the circulation or applied an estimated percentage based on protein digestibility. However, such estimations can introduce large artifacts in the assessment of whole-body protein metabolism. The preferred estimation approach is based on the extrapolation of intrinsically labeled protein-derived plasma bioavailability data obtained in a similar experimental design setting. Here, we provide reference data on exogenous plasma amino acid release that can be applied to allow a more accurate routine assessment of postprandial protein metabolism. More work in this area is needed to provide a more extensive reference data set.

Impact of increased protein intake in older adults: a 12-week double-blind randomised controlled trial

BACKGROUND

Emerging evidence suggests health-promoting properties of increased protein intake. There is increased interest in plant protein but a dearth of information in relation to its impact on muscle function. The objective of the present work was to examine the impact of intake of different types of proteins on muscle functional parameters including handgrip strength, biomarkers of metabolic health, sleep quality and quality of life in a group of older adults.

METHODS

Healthy men and women aged 50 years and older entered a double-blinded, randomised, controlled nutritional intervention study with three parallel arms: high plant protein, high dairy protein and low protein. Participants consumed once daily a ready-to-mix shake (containing 20 g of protein in high protein groups) for 12 weeks. Changes in handgrip and leg strength, body composition, metabolic health, quality of life and sleep quality were analysed by linear mixed models in an intention-to-treat approach.

RESULTS

Eligible participants (n = 171) were randomly assigned to the groups (plant: n = 60, dairy: n = 56, low protein: n = 55) and 141 completed the study. Handgrip strength increased after the intervention (Ptime = 0.038), with no significant difference between the groups. There was no significant difference between groups for any other health outcomes.

CONCLUSIONS

In a population of older adults, increasing protein intake by 20 g daily for 12 weeks (whether plant-based or dairy-based) did not result in significant differences in muscle function, body composition, metabolic health, sleep quality or quality of life, compared with the low protein group.

Obesity pharmacotherapy in older adults: a narrative review of evidence

The prevalence of obesity in older adults (people aged >60 years) is increasing in line with the demographic shift in global populations. Despite knowledge of obesity-related complications in younger adults (increased risk of type 2 diabetes, liver and cardiovascular disease and malignancy), these considerations may be outweighed, in older adults, by concerns regarding weight-loss induced reduction in skeletal muscle and bone mass, and the awareness of the 'obesity paradox'. Obesity in the elderly contributes to various obesity-related complications from cardiometabolic disease and cancer, to functional decline, worsening cognition, and quality of life, that will have already suffered an age-related decline. Lifestyle interventions remain the cornerstone of obesity management in older adults, with emphasis on resistance training for muscle strength and bone mineral density preservation. However, in older adults with obesity refractory to lifestyle strategies, pharmacotherapy, using anti-obesity medicines (AOMs), can be a useful adjunct. Recent evidence suggests that intentional weight loss in older adults with overweight and obesity is effective and safe, hence a diminishing reluctance to use AOMs in this more vulnerable population. Despite nine AOMs being currently approved for the treatment of obesity, limited clinical trial evidence in older adults predominantly focuses on incretin therapy with glucagon-like peptide-1 receptor agonists (liraglutide, semaglutide, and tirzepatide). AOMs enhance weight loss and reduce cardiometabolic events, while maintaining muscle mass. Future randomised controlled trials should specifically evaluate the effectiveness of novel AOMs for long-term weight management in older adults with obesity, carefully considering the impact on body composition and functional ability, as well as health economics.

Nutritional Habits of Hungarian Older Adults

There are many nutritional changes that come with aging, mostly as consequences of health regression. Malnutrition and overweight often start with inadequate food consumption, followed by alterations in biochemical indices and body composition. In our study, we aimed to analyze the feeding habits and energy and nutrient intake of a Hungarian elderly population, focusing on macronutrient, water, fruit, and vegetable consumption while searching for possible nutritional factors leading to NCD and many other chronic diseases in this population. Two questionnaires were used. These were the Mini Nutritional Assessment (MNA) and one asking about nutritional habits, and a 3-day feeding diary was also filled. Subjects (n = 179, 111; females (F), 68 males (M), older than 50 years were recruited. Based on MNA results, 78 adults (43.57% of the studied population) were malnourished or at risk of malnutrition, although, according to BMI categories, 69% were overweight and 7.3% were obese among M, while 42.3% were overweight among F. The average daily meal number was diverse. The amount of people consuming fruit (11.7%) and vegetables (8.93%) several times a day was extremely low (15.3% of F and 4.4% of M). Daily fruit consumption in the whole sample was 79.3%. Overall, 36.3% consumed 1 L of liquid and 0.5 L of consumption was found in 15.1% of participants. A significant gender difference was found in water consumption, with F drinking more than M (p ≤ 0.01). In our sample, 27.93% of the respondents took dietary supplements. Further analysis and research are needed to explore the specific health implications of and reasons behind these findings.

Daily Dietary Protein Distribution Does Not Influence Changes in Body Composition During Weight Loss in Women of Reproductive Years with Overweight or Obesity: A Randomized Controlled Trial

BACKGROUND

Preservation of fat-free mass (FFM) during intentional weight loss is challenging yet important to maintain a resting metabolic rate. A balanced protein distribution of 25-30 g per meal improves 24-h muscle protein synthesis, which may promote FFM maintenance and greater reductions in fat mass (FM) during weight loss in women.

OBJECTIVES

We aimed to determine whether the daily dietary protein distribution pattern during energy restriction influences changes in body composition in women of reproductive age. We hypothesized that evenly distributing protein across meals compared with the usual intake pattern of consuming most of the protein at the dinner meal would be superior in preserving FFM while reducing FM during weight loss.

METHODS

Healthy women (n = 43) aged 20-44 y with a BMI of 28-45 kg/m2 completed a randomized parallel feeding study testing 2 patterns of daily protein intake (even distribution across all meals compared with a skewed distribution with most protein consumed at the evening meal). Participants completed an 8-wk controlled 20% energy restriction (all foods provided), followed by an 8-wk self-choice phase in which participants were asked to maintain a similar diet and dietary pattern when purchasing and consuming their own foods. Body composition was measured at baseline, week 8, and week 16. Data were analyzed using mixed models. Statistical significance was set at P < 0.05. Data are presented as differences in least squares means ± SE.

RESULTS

No significant main effects of group or group-by-time interactions were observed. All measures exhibited the main effect of time (P < 0.001). Overall, body weight, FFM, FM, and body fat percentage decreased 5.6 ± 0.4, 1.0 ± 0.2, 4.6 ± 0.4 kg, and 2.3 ± 0.2%, respectively, during this 16-wk study.

CONCLUSION

Daily dietary protein distribution at a fixed protein level does not appear to influence changes in body composition during weight loss in women of reproductive age.

CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE WHERE IT WAS OBTAINED

NCT03202069 https://classic.

CLINICALTRIALS

gov/ct2/show/NCT03202069.

The effects of protein intake higher than the recommended value on body composition changes after bariatric surgery: A meta-analysis of randomized controlled trials

BACKGROUND & AIMS

There is a lack of a meta-analysis to comprehensively assess the effectiveness of higher protein intake in addition to the recommended value on body composition post-bariatric surgery. We aimed to perform a meta-analysis of randomized controlled trials to determine the effects of protein intake higher than the recommended value on body composition changes after bariatric surgery.

METHODS

Electronic databases, including Scopus, PubMed/Medline, and Web of Sciences, were searched until July 2023. Studies that assessed the effect of protein intake higher than the recommended value on postoperative body composition, i.e., weight, body mass index (BMI), fat mass (FM), fat-free mass (FFM), percent fat mass (PFM), and percent total weight loss (%TWL), were eligible. For each outcome, the mean and standard deviation (for changes from baseline) were used to synthesize the data.

RESULTS

Eight trials were included in the current study. The results of the meta-analysis indicated protein intake higher than the recommended value after bariatric surgery led to more weight loss by 4.95 kg (95 % CI: -9.41 to -0.49) and FM loss by 7.64 kg (95 % CI: -14.01 to -1.28) compared with the control group. However, it had no significant effects on postoperative changes in BMI, FFM, PFM, or %TWL. There were no significant differences in body composition between protein sources obtained from diet and supplementation. When data was stratified based on the amount of added protein, we found a significant reduction in weight (MD: -7.80 kg; 95 % CI: -14.50 to -1.10) in patients who consumed protein ≥ 40 g/d in addition to the recommended value. Besides, protein intake higher than the recommended value declined FFM loss in patients who underwent laparoscopic sleeve gastrectomy (LSG) (MD: 6.52 kg; 95 % CI: 0.99 to 12.02).

CONCLUSION

The results of the current meta-analysis indicated that protein intake higher than the recommended value might cause greater weight and FM loss after bariatric surgery than a normal protein diet. However, our findings did not support the role of additional protein in the preservation of FFM, except in patients with LSG.

Protein intake and body weight, fat mass and waist circumference: an umbrella review of systematic reviews for the evidence-based guideline on protein intake of the German Nutrition Society

PURPOSE

This umbrella review aimed to assess whether dietary protein intake with regard to quantitative (higher vs. lower dietary protein intake) and qualitative considerations (total, plant-based or animal-based protein intake) affects body weight (BW), fat mass (FM) and waist circumference (WC).

METHODS

A systematic literature search was conducted in PubMed, Embase and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with and without meta-analyses of prospective studies published between 04 October 2007 and 04 January 2022. Methodological quality and outcome-specific certainty of evidence of the retrieved SRs were assessed by using AMSTAR 2 and NutriGrade, respectively, in order to rate the overall certainty of evidence using predefined criteria.

RESULTS

Thirty-three SRs were included in this umbrella review; 29 were based on randomised controlled trials, a few included cohort studies. In studies without energy restriction, a high-protein diet did not modulate BW, FM and WC in adults in general (all "possible" evidence); for older adults, overall certainty of evidence was "insufficient" for all parameters. Under hypoenergetic diets, a high-protein diet mostly decreased BW and FM, but evidence was "insufficient" due to low methodological quality. Evidence regarding an influence of the protein type on BW, FM and WC was "insufficient".

CONCLUSION

"Possible" evidence exists that the amount of protein does not affect BW, FM and WC in adults under isoenergetic conditions. Its impact on the reduction in BW and FM under hypoenergetic conditions remains unclear; evidence for an influence of protein type on BW, FM and WC is "insufficient".

Pathophysiological-Based Nutritional Interventions in Cirrhotic Patients with Sarcopenic Obesity: A State-of-the-Art Narrative Review

In recent decades, following the spread of obesity, metabolic dysfunction has come to represent the leading cause of liver disease. The classical clinical presentation of the cirrhotic patient has, therefore, greatly changed, with a dramatic increase in subjects who appear overweight or obese. Due to an obesogenic lifestyle (lack of physical activity and overall malnutrition, with an excess of caloric intake together with a deficit of proteins and micronutrients), these patients frequently develop a complex clinical condition defined as sarcopenic obesity (SO). The interplay between cirrhosis and SO lies in the sharing of multiple pathogenetic mechanisms, including malnutrition/malabsorption, chronic inflammation, hyperammonemia and insulin resistance. The presence of SO worsens the outcome of cirrhotic patients, affecting overall morbidity and mortality. International nutrition and liver diseases societies strongly agree on recommending the use of food as an integral part of the healing process in the comprehensive management of these patients, including a reduction in caloric intake, protein and micronutrient supplementation and sodium restriction. Based on the pathophysiological paths shared by cirrhosis and SO, this narrative review aims to highlight the nutritional interventions currently advocated by international guidelines, as well as to provide hints on the possible role of micronutrients and nutraceuticals in the treatment of this multifaceted clinical condition.

8. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Nutritional strategies to optimise musculoskeletal health for fall and fracture prevention: Looking beyond calcium, vitamin D and protein

Falls and osteoporotic fractures are a major public health problem, particularly among older adults. A third of individuals aged 65 years and over fall at least once each year, with up to 20 % of these resulting in serious injury, including fracture. In conjunction with regular exercise, the importance of diet for musculoskeletal health has largely focused upon calcium, vitamin D, and protein, particularly in the context of preventing falls and fractures. Whilst there is evidence for the benefits of these nutrients for musculoskeletal health, other aspects of the diet remain largely underexplored. For example, vegetables are rich sources of macro- and micronutrients that are essential for muscle function and bone health, which are key factors in the prevention of falls and fractures. Recent work has highlighted the importance of nutrients such as vegetable-derived nitrate and vitamin K1 in optimising muscle strength, physical function, and bone quality. In the context of dietary patterns, vegan/plant-based diets have recently gained popularity due to perceived health benefits, animal welfare, or to tackle climate change. The elimination and/or substitution of animal-based products for plant foods (without careful planning and/or expert dietary guidance) could, however, have long-term negative musculoskeletal consequences; a trend uncovered by recent evidence. Within the overarching theme of nutrition for fall and fracture prevention in older populations, the aim of this review is to (i) summarise the current evidence for calcium, vitamin D and protein; (ii) describe the importance of vegetables and selected nutrients, such as nitrate and vitamin K1, for muscle function and bone structural integrity; and (iii) highlight current evidence around different dietary patterns (e.g., plant-based, diet quality, data driven approaches) and their impact on musculoskeletal health.

Do macronutrient intakes affect obesity indices in Jordanian adults?

OBJECTIVE

To determine whether macronutrient intake is associated with novel obesity indices, including the conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), and weight-adjusted-waist index (WWI).

METHODOLOGY

A cross-sectional survey was conducted with 491 adults (344 males and 147 females) working at different universities in Jordan (July-December 2019). Daily intake of energy (kcal), carbohydrates (g), protein (g), and fat (g) was obtained using 24-h recalls collected over 2 days. Additionally, obesity indices were calculated.

RESULTS

Regardless of sex, energy, and carbohydrate intakes had a moderately significant positive association, whereas protein and fat intakes had a weakly significant association with BAI, AVI, and BRI. CI and WWI showed a weakly significant association with all macronutrients in males, a moderate correlation with energy and carbohydrate intake, and a weak association with fat and protein intake in females. Male participants had significant increases in the CI (T1 = 1.29 ± 0.01 vs. T3 = 1.36 ± 0.01, p = .018), AVI (T1 = 17.96 ± 0.52 vs. T3 = 22.81 ± 0.57, p = .011), and WWI (T1 = 10.72 ± 0.11 vs. T3 = 11.29 ± 0.09, p = .047) indices scores through the carbohydrate intake tertiles. Additionally, there was a significant increase in scores of AVI (T1 = 18.60 ± 0.56 vs. T3 = 21.42 ± 0.46, p = .048) and an almost significant increase in CI (T1 = 1.30 ± 0.01vs. T3 = 1.33 ± 0.01, p = .056) through the tertiles of protein intake.

CONCLUSION

Macronutrients were significantly associated with all indices. The effect of macronutrients on obesity indices is sex-based. Among men, CI, AVI, and WWI were the indices most affected by carbohydrate and protein intakes. Future studies should further investigate food sources and macronutrient quality.

Considerations on the Weight Loss-Associated Glucagon-like Peptide-1 Receptor Agonists for Older People

Obesity rates for older people have increased around the world1 with rates tripling over the past four decades.² While previously considered a phenomenon of developed countries, the increased prevalence of obesity is now established in developing countries as well.³ Factors stimulating this epidemic include modifications in the global food supply chain, rise in consumption and availability of energy-dense, low-nutrient foods, sedentary occupations, expanding urbanization, changes in transportation means, as well as environmental components.³ The increasing prevalence of obesity in older people in the United States over time has been well documented by federal agencies. Over the time periods 1999-2002, 2003-2006, and 2007-2010, a linear increase in the prevalence of obesity among older men in all age groups was observed. The obesity prevalence among men 65 to 74 years of age increased from about 31.6% in 1999-2002 to 41.5% in 2007-2010. In men older than 74 years of age, obesity prevalence increased from 17.7% in 1999-2002 to 26.5% in 2007-2010. Of interest is that, in women, the change over the same time period was not statistically significant for the older age groups (40.3% obesity in 65- to 74-year-old women and 28.7% in women older than 74 years of age in the 2007-2010 analysis period).⁴.

Chronic Thermogenic Dietary Supplement Consumption: Effects on Body Composition, Anthropometrics, and Metabolism

Multi-ingredient thermogenic supplements can acutely increase resting energy expenditure (REE) and subjective energy. However, less is understood about the effects of chronic consumption on body composition, metabolism, and subjective variables such as mood, sleep quality, and eating behaviors. Fifty-two healthy, exercise-trained participants (50% female; mean ± SD age: 23.5 ± 3.0 years; body fat percentage: 27.3 ± 8.0%) were randomized 2:2:1 to take a whey protein supplement alone (PRO; n = 20), in combination with a thermogenic supplement (PRO + FB; n = 19), or no supplement at all (CON; n = 13) for four weeks. Body composition, anthropometric, metabolic, hemodynamic, and subjective outcomes were collected before and after the intervention. Greater changes in REE occurred in PRO + FB as compared to CON (111.2 kcal/d, 95% CI 2.4 to 219.9 kcal/d, p = 0.04), without significant differences between PRO and CON (42.7 kcal/d, 95% CI -65.0 to 150.3 kcal/d, p = 0.61) or between PRO + FB and PRO (68.5 kcal/d, 95% CI -28.3, 165.3, p = 0.21). No changes in hemodynamic outcomes (blood pressure and heart rate) were observed. In exercising adults, four weeks of supplementation with protein and a multi-ingredient thermogenic product maintained fasted REE as compared to no supplementation, for which a decrease in REE was observed, without differential effects on body composition, anthropometrics, or subjective variables.

Dose-Response of Myofibrillar Protein Synthesis To Ingested Whey Protein During Energy Restriction in Overweight Postmenopausal Women: A Randomized, Controlled Trial

BACKGROUND

Diet-induced weight loss is associated with a decline in lean body mass, as mediated by an impaired response of muscle protein synthesis (MPS). The dose-response of MPS to ingested protein, with or without resistance exercise, is well characterized during energy balance but limited data exist under conditions of energy restriction in clinical populations.

OBJECTIVE

To determine the dose-response of MPS to ingested whey protein following short-term diet-induced energy restriction in overweight, postmenopausal, women at rest and postexercise.

DESIGN

Forty middle-aged (58.6±0.4 y), overweight (BMI: 28.6±0.4), postmenopausal women were randomly assigned to 1 of 4 groups: Three groups underwent 5 d of energy restriction (∼800 kcal/d). On day 6, participants performed a unilateral leg resistance exercise bout before ingesting either a bolus of 15g (ERW15, n = 10), 35g (ERW35, n = 10) or 60g (ERW60, n = 10) of whey protein. The fourth group (n = 10) ingested a 35g whey protein bolus after 5 d of an energy balanced diet (EBW35, n = 10). Myofibrillar fractional synthetic rate (FSR) was calculated under basal, fed (FED) and postexercise (FED-EX) conditions by combining an L-[ring-13C6] phenylalanine tracer infusion with the collection of bilateral muscle biopsies.

RESULTS

Myofibrillar FSR was greater in ERW35 (0.043±0.003%/h, P = 0.013) and ERW60 (0.042±0.003%/h, P = 0.026) than ERW15 (0.032 ± 0.003%/h), with no differences between ERW35 and ERW60 (P = 1.000). Myofibrillar FSR was greater in FED (0.044 ± 0.003%/h, P < 0.001) and FED-EX (0.048 ± 0.003%/h, P < 0.001) than BASAL (0.027 ± 0.003%/h), but no differences were detected between FED and FED-EX (P = 0.732) conditions. No differences in myofibrillar FSR were observed between EBW35 (0.042 ± 0.003%/h) and ERW35 (0.043 ± 0.003%/h, P = 0.744).

CONCLUSION

A 35 g dose of whey protein, ingested with or without resistance exercise, is sufficient to stimulate a maximal acute response of MPS following short-term energy restriction in overweight, postmenopausal women, and thus may provide a per serving protein recommendation to mitigate muscle loss during a weight loss program.

TRIAL REGISTRY

clinicaltrials.gov (ID: NCT03326284).

Impact of Geroscience on Therapeutic Strategies for Older Adults With Cardiovascular Disease: JACC Scientific Statement

Geroscience posits that cardiovascular disease (CVD) and other chronic diseases result from progressive erosion of the effectiveness of homeostatic mechanisms that oppose age-related accumulation of molecular damage. This hypothetical common root to chronic diseases explains why patients with CVD are often affected by multimorbidity and frailty and why older age negatively affects CVD prognosis and treatment response. Gerotherapeutics enhance resilience mechanisms that counter age-related molecular damage to prevent chronic diseases, frailty, and disability, thereby extending healthspan. Here, we describe the main resilience mechanisms of mammalian aging, with a focus on how they can affect CVD pathophysiology. We next present novel gerotherapeutic approaches, some of which are already used in management of CVD, and explore their potential to transform care and management of CVD. The geroscience paradigm is gaining traction broadly in medical specialties, with potential to mitigate premature aging, reduce health care disparities, and improve population healthspan.

Poultry Consumption and Human Cardiometabolic Health-Related Outcomes: A Narrative Review

Poultry meats, in particular chicken, have high rates of consumption globally. Poultry is the most consumed type of meat in the United States (US), with chicken being the most common type of poultry consumed. The amounts of chicken and total poultry consumed in the US have more than tripled over the last six decades. This narrative review describes nutritional profiles of commonly consumed chicken/poultry products, consumption trends, and dietary recommendations in the US. Overviews of the scientific literature pertaining to associations between, and effects of consuming chicken/poultry on, body weight and body composition, cardiovascular disease (CVD), and type II diabetes mellitus (T2DM) are provided. Limited evidence from randomized controlled trials indicates the consumption of lean unprocessed chicken as a primary dietary protein source has either beneficial or neutral effects on body weight and body composition and risk factors for CVD and T2DM. Apparently, zero randomized controlled feeding trials have specifically assessed the effects of consuming processed chicken/poultry on these health outcomes. Evidence from observational studies is less consistent, likely due to confounding factors such as a lack of a description of and distinctions among types of chicken/poultry products, amounts consumed, and cooking and preservation methods. New experimental and observational research on the impacts of consuming chicken/poultry, especially processed versions, on cardiometabolic health is sorely needed.

Effects of intermittent fasting on cognitive health and Alzheimer's disease

OBJECTIVE

Caloric restriction by intermittent fasting produces several metabolic changes, such as increased insulin sensitivity and use of ketone bodies as energy sources. In humans, intermittent fasting has been studied in hypertension, diabetes, and related conditions, but, to date, not as a strategy to reduce the risk of emergent dementia. In this scoping review, the relevance of intermittent fasting as a potential preventive intervention for Alzheimer's dementia is explored.

BACKGROUND

The beneficial effects of calorie restriction have been documented in animals and humans. Decreased oxidative stress damage and attenuated inflammatory responses are associated with intermittent fasting. These changes have a favorable impact on the vascular endothelium and stress-induced cellular adaptation.

RESULTS

Physiological alterations associated with fasting have profound implications for pathological mechanisms associated with dementias, particularly Alzheimer's disease. Compared with ad libitum feeding, caloric restriction in animals was associated with a reduction in β-amyloid accumulation, which is the cardinal pathological marker of Alzheimer's disease. Animal studies have demonstrated synaptic adaptations in the hippocampus and enhanced cognitive function after fasting, consistent with these theoretical frameworks. Furthermore, vascular dysfunction plays a crucial role in Alzheimer's disease pathology, and intermittent fasting promotes vascular health.

CONCLUSIONS

These observations lead to a hypothesis that intermittent fasting over the years will potentially reverse or delay the pathological process in Alzheimer's disease.

Association of Macronutrients Intake with Body Composition and Sarcopenic Obesity in Children and Adolescents: A Population-Based Analysis of the National Health and Nutrition Examination Survey (NHANES) 2011-2018

The association of macronutrients intake with body composition and sarcopenic obesity remains uncertain in children and adolescents. We aimed to explore the association between macronutrients intake and body composition, especially sarcopenic obesity, in children and adolescents residing in the United States. The study utilized data from 5412 participants aged 6-17 years who attended NHANES between 2011 and 2018. Body composition was assessed using DXA, and nutrient intake was based on 24-h recall. Multivariable linear regression and multinomial logistic regression were used. The unweighted prevalence of sarcopenic obesity was 15.6%. A higher percentage of energy (5 %E) from fat was inversely associated with muscle mass but positively associated with fat mass and sarcopenic obesity. Substituting carbohydrate (5 %E) with fat decreased muscle mass by 0.03 (95% CI 0.01 to 0.06) but increased fat mass by 0.03 (95% CI 0.01 to 0.06) and increased the prevalence of sarcopenic obesity by 254% (95% CI 15% to 487%). Replacing protein intake with fat intake also increased the OR of sarcopenic obesity (OR, 2.36 [95% CI 1.18 to 3.18]). In conclusion, a high-fat diet, coupled with low carbohydrate/protein intake, is associated with sarcopenic obesity among children and adolescents. The change in children's diet towards a healthy diet with low fat composition may help prevent sarcopenic obesity. However, randomized clinical trials or longitudinal studies are needed to further validate our findings.

Nutrition and exercise interventions to improve body composition for persons with overweight or obesity near retirement age: A systematic review and network meta-analysis of randomised controlled trials

The retirement phase is an opportunity to integrate healthy (nutrition/exercise) habits into daily life. We conducted this systematic review to assess which nutrition and exercise interventions most effectively improve body composition (fat/muscle mass), body mass index (BMI) and waist circumference (WC) in persons with obesity/overweight near retirement age (ages 55-70). We conducted a systematic review and network-meta-analysis (NMA) of randomised controlled trials, searching four databases from their inception up to 12 July 2022. The NMA was based on a random effects model, pooled mean differences, standardised mean differences, their 95% confidence intervals, and correlations with multi-arm studies. Subgroup and sensitivity analyses were also conducted. 92 studies were included, 66 of which with 4957 participants could be used for the NMA. Identified interventions were clustered into 12 groups: no intervention, energy restriction (i.e. 500-1000 kcal), energy restriction plus high protein (HP) intake (1.1-1.7 g/kg/body weight), intermittent fasting, mixed exercise (aerobic and resistance), resistance training (RT), aerobic training (AT), HP plus RT, energy restriction plus HP plus exercise, energy restriction plus RT, energy restriction plus AT, and energy restriction plus mixed exercise (ME). Intervention durations ranged from 8 weeks to 6 months. Body fat was reduced with energy restriction plus any exercise or plus HP intake. Energy restriction alone was less effective and tended to decrease muscle mass. Muscle mass was only significantly increased with ME. All other interventions including exercise effectively preserved muscle mass. A BMI and/or WC decrease was achieved with all interventions except AT/RT alone or RT plus HP. Overall, the most effective strategy for nearly all outcomes was combining energy restriction with RT or ME and HP. Healthcare professionals involved in the management of persons with obesity need to be aware that an energy-restricted diet alone may contribute to sarcopenic obesity in persons near retirement age. This network meta-analysis is registered at https://www.crd.york.ac.uk/prospero/as CRD42021276465.

Benefits of Whey Proteins on Type 2 Diabetes Mellitus Parameters and Prevention of Cardiovascular Diseases

Type 2 diabetes mellitus (T2DM) is a major cause of morbidity and mortality, and it is a major risk factor for the early onset of cardiovascular diseases (CVDs). More than genetics, food, physical activity, walkability, and air pollution are lifestyle factors, which have the greatest impact on T2DM. Certain diets have been shown to be associated with lower T2DM and cardiovascular risk. Diminishing added sugar and processed fats and increasing antioxidant-rich vegetable and fruit intake has often been highlighted, as in the Mediterranean diet. However, less is known about the interest of proteins in low-fat dairy and whey in particular, which have great potential to improve T2DM and could be used safely as a part of a multi-target strategy. This review discusses all the biochemical and clinical aspects of the benefits of high-quality whey, which is now considered a functional food, for prevention and improvement of T2DM and CVDs by insulin- and non-insulin-dependent mechanisms.

Distinct dietary risk factors for incident osteoporotic fractures in early and late postmenopausal phase women

INTRODUCTION

Available evidence on favorable nutritional factors for preventing osteoporosis remains controversial. Considering the recent increases in life expectancy, we investigated the relationship between incident osteoporotic fractures and dietary habits in early and late postmenopausal phase women.

MATERIALS AND METHODS

Subjects were Japanese postmenopausal outpatients recruited at a primary care institution in Nagano Prefecture (Nagano Cohort Study). Patients with critical or acute illness or secondary osteoporosis were not included in this study. In total, 1,071 participants were prospectively followed for a mean of 5.8 years. The cohort was divided into early (≤ 70 years) and late (> 70 years) postmenopausal phases based on median age. Dietary nutrient intake was estimated by the food frequency questionnaire method. According to baseline nutrient intake characteristics, we focused on protein/energy and Ca/NaCl intake ratios, which were also divided by the median values.

RESULTS

Kaplan-Meier plots revealed a significantly higher occurrence of fractures for the high protein/energy intake group in early postmenopausal subjects (P = 0.009), whereas the low Ca/NaCl intake group in late postmenopausal subjects exhibited a significantly earlier occurrence of fractures (P = 0.002). Multivariate Cox regression uncovered significant independent risks of higher protein/energy (HR 1.35; 95% CI 1.04-1.74) and lower Ca/NaCl (HR 0.79; 95% CI 0.63-0.99) intake ratios for incident osteoporotic fractures in the early and late postmenopausal cohorts, respectively.

CONCLUSION

Distinct dietary risk factors for osteoporotic fractures were identified in early and late postmenopausal phase women. Appropriate nutritional guidance according to patient age will be important for maintaining bone health and quality of life.

Weight cycling based on altered immune microenvironment as a result of metaflammation

As a result of the obesity epidemic, more people are concerned about losing weight; however, weight regain is common, leading to repeated weight loss and weight cycling. The health benefits of early weight loss are nullified by weight regain after weight cycling, which has much more severe metabolic consequences. Weight cycling alters body composition, resulting in faster fat recovery and slower muscle reconstruction. This evident fat accumulation, muscle loss, and ectopic fat deposition destroy the intestinal barrier, increase the permeability of the small intestinal epithelium, and cause the lipotoxicity of lipid metabolites and toxins to leak into extraintestinal tissues and circulation. It causes oxidative stress and hypoxia in local tissues and immune cell infiltration in various tissues, all contributing to the adaptation to this metabolic change. Immune cells transmit inflammatory responses in adipose and skeletal muscle tissue by secreting cytokines and adipokines, which mediate immune cell pathways and cause metaflammation and inefficient metabolic degradation. In this review, we focus on the regulatory function of the immunological microenvironment in the final metabolic outcome, with a particular emphasis on the cellular and molecular processes of local and systemic metaflammation induced by weight cycling-induced changes in body composition. Metaflammation in adipose and muscle tissues that is difficult to relieve may cause weight cycling. As this chronic low-grade inflammation spreads throughout the body, metabolic complications associated with weight cycling are triggered. Inhibiting the onset and progression of metabolic inflammation and enhancing the immune microenvironment of adipose and muscle tissues may be the first step in addressing weight cycling.

Supplementation with Whey Protein, but Not Pea Protein, Reduces Muscle Damage Following Long-Distance Walking in Older Adults

Background: Adequate animal-based protein intake can attenuate exercise induced-muscle damage (EIMD) in young adults. We examined the effects of 13 days plant-based (pea) protein supplementation compared to whey protein and placebo on EIMD in active older adults. Methods: 47 Physically active older adults (60+ years) were randomly allocated to the following groups: (I) whey protein (25 g/day), (II) pea protein (25 g/day) or (III) iso-caloric placebo. Blood concentrations of creatine kinase (CK) and lactate dehydrogenase (LDH), and skeletal muscle mass, muscle strength and muscle soreness were measured prior to and 24 h, 48 h and 72 h after a long-distance walking bout (20−30 km). Results: Participants walked 20−30 km and 2 dropped out, leaving n = 15 per subgroup. The whey group showed a significant attenuation of the increase in EIMD at 24 h post-exercise compared to the pea and placebo group (CK concentration: 175 ± 90 versus 300 ± 309 versus 330 ± 165, p = p < 0.001). No differences in LDH levels, muscle strength, skeletal muscle mass and muscle soreness were observed across groups (all p-values > 0.05). Conclusions: Thirteen days of pea protein supplementation (25 g/day) does not attenuate EIMD in older adults following a single bout of prolonged walking exercise, whereas the whey protein supplementation group showed significantly lower post-exercise CK concentrations.

Early Time-Restricted Eating Reduces Weight and Improves Glycemic Response in Young Adults: A Pre-Post Single-Arm Intervention Study

INTRODUCTION

Time-restricted eating (TRE) has cardiometabolic health benefits by optimizing circadian rhythms. However, limited data are available on the effect of early TRE in young adults. The objective of this pre-post single-arm trial was to test the effect of TRE on body composition and cardiometabolic risk factors and to evaluate changes in meal and sleep timing by TRE among young adults with typically late bedtime.

METHODS

This 4-week intervention was conducted in healthy young adults aged 18-39 years. Dietary records with time logs were collected before and during the intervention, and nutrient intake and meal timing were evaluated. Snack packages containing 20 g of protein per day were provided weekly. Body composition was measured weekly using bioelectrical impedance analysis. Blood samples were collected before and after the intervention, and cardiometabolic parameters were evaluated.

RESULTS

Of the 36 screened participants, 34 completed the study (completion rate 94.4%). The average age was 23.4 ± 2.9 years with 64.7% female. The mean wake-up time and bedtime were 09:16 ± 01:26 and 01:51 ± 01:39 with average sleep duration of 7.4 ± 1.4 h. Body weight and fat mass, excluding muscle mass, were significantly reduced over 4 weeks compared to baseline only in the early TRE group starting before noon. The early TRE group also showed significantly reduced fasting glucose, fasting insulin, and serum triglyceride (TG) levels after 4 weeks. However, the late TRE group starting after noon showed no significant changes except a reduced TG level. The meal timing was changed by TRE, where the first meal was delayed and the last meal was shifted. Neither sleep duration nor timing was significantly changed by TRE. Energy intakes were not different, but protein intake increased from 19.2% to 22.6% due to snack packages during intervention. However, no significant correlation between nutrient intakes and body composition changes was found. There were no adverse events related to study participation.

CONCLUSIONS

An early TRE regimen may be a feasible and effective strategy to manage body composition and cardiometabolic risk factors in young adults without altering the sleep-wake cycle.

Adaptation and validation of a protein intake screening tool for a UK adult population

Adequate dietary protein intake is important in human subjects for maintaining muscle turnover, determining the protein content of tissues and thus the preservation of muscle mass and function as we age. A screening tool to assess if an older individual is likely to have a lower dietary protein intake (predicted probability of protein intake ≤1⋅0 g/kg per d), has been developed for a Netherlands dietary profile, but this has not been validated in a UK population. This study aimed to adapt and then validate the protein screening tool for use in a UK population. Amendment of the tool was undertaken using data from UK BioBank and the UK National Diet and Nutrition Survey to reflect protein sources in the UK diet. Validation of the amended version of the protein screener screening tool was conducted using protein intake derived from a food frequency questionnaire (FFQ) in a sample of UK adults (n = 184) (age range 18-91 years) as the reference standard. Using the FFQ, 40 % of respondents (n = 74) reported a protein intake of ≤1⋅0 g per kg body mass. The discriminative accuracy of the amended screener was tested using receiver operating characteristic (ROC) curves. The area under the curve for the ROC was 0⋅731 (95 % CI 0⋅657, 0⋅805), indicating that the amended screener may be a valid tool to screen for individuals consuming ≤1⋅0 g/kg adjusted BM/d in an adult UK population. This protein screener tool is a potential method to screen individuals with a likelihood of habitually consuming protein intakes of ≤1⋅0 g/kg per d. Further validation is needed using a more robust dietary intake methodology and for specific groups, such as older adults. The screener may be applicable across healthcare, clinical and research applications.

Effects of Whey Protein or Its Hydrolysate Supplements Combined with an Energy-Restricted Diet on Weight Loss: A Randomized Controlled Trial in Older Women

An energy-restricted weight-loss approach has limitations when it used in the elderly, especially because of muscle loss. We aimed to assess the effects of whey protein (WP) or WP hydrolysate (WPH) combined with an energy-restricted diet (ERD) on weight reduction and muscle preservation in older women with overweight and obesity. A total of 60 women were randomized to the control (ERD), WP (ERD + 20 g/d WP) or WPH (ERD + 20 g/d WPH) group, using a 1:1:1 allocation ratio. After an 8-week intervention, body composition, gut microbiota, and serum metabolomics changes were compared among the three groups. The reductions in body weight (−1.11 ± 1.11 vs. −2.34 ± 1.35, p < 0.05), BMI (−0.46 ± 0.45 vs. −0.97 ± 0.54, p < 0.05), and body fat (−0.70 ± 0.92 vs. −2.45 ± 1.65, p < 0.01) were higher in the WPH group than in the control group. Body fat (%) was significantly decreased in the two protein groups. Fat-free mass did not significantly change among the three groups. Serum metabolomics showed that the tricarboxylic acid cycle pathway was upregulated in the WPH group. No significant changes in microbiota were observed among the groups. In conclusion, WP or WPH supplementation combined with an energy-restricted diet benefits older women during weight loss. WPH was more effective, possibly due to increased energy metabolism.

Lifestyle Strategies for the Management of Obesity in Older Adults: From Controversies to Alternative Interventions

Improvements in infection control, management of chronic diseases and impressive advancements in modern medicine have all contributed to increases in life expectancy [...].

Ultra-processed food consumption is associated with increase in fat mass and decrease in lean mass in Brazilian women: A cohort study

Objective

To investigate the association between ultra-processed food consumption at 23–25 years of age and measurements of body composition–fat mass, fat mass distribution and lean mass at 37–39 years of age in Brazilian adults.

Methods

1978/1979 birth cohort study conducted with healthy adults from Ribeirão Preto, São Paulo, Brazil. A total of 1,021 individuals participated in the fat mass analysis (measured by air displacement plethysmography) and 815 in the lean mass analysis and fat mass distribution (assessed by dual energy X-ray absorptiometry). Food consumption was evaluated by a food frequency questionnaire. Food items were grouped according to the level of processing as per the NOVA classification. Ultra-processed food consumption was expressed as a percentage of total daily intake (g/day). Linear regression models were used to estimate the effect of ultra-processed food consumption (g/day) on body mass index, body fat percentage, fat mass index, android fat, gynoid fat, android-gynoid fat ratio, lean mass percentage, lean mass index and appendicular lean mass index. Marginal plots were produced to visualize interactions.

Results

The mean daily ultra-processed food consumption in grams was 35.8% (813.3 g). There was an association between ultra-processed food consumption and increase in body mass index, body fat percentage, fat mass index, android fat and gynoid fat and decrease in lean mass percentage, only in women.

Conclusion

A high ultra-processed food consumption is associated with a long-term increase in fat mass and a decrease in lean mass in adult women.

The role of protein intake in the relationship between egg consumption and body composition in young adults. A mediation analysis

BACKGROUND & AIMS

To date, the literature examining the effects of whole-egg consumption on health outcomes focuses primarily on cardiovascular health markers; however, a significant gap exists in the literature about how egg consumption may influence body composition indicators. The aim of this study was to estimate the association between egg consumption and body composition indicators and to examine whether this relationship is mediated by protein intake in young adults.

METHODS

A cross-sectional study was conducted involving 355 first-year university students (aged 18-30 years) from a Spanish public university. Body composition was measured using bioimpedance and dual-energy X-ray absorptiometry (DXA) and fitness components were determined using the course-navette test. Egg consumption and protein intake (both in g/day/kg of body weight) were determined using a 137-item Food-Frequency Questionnaire. ANCOVA models were used to test the mean differences in body composition indicators (body mass index [BMI], ratio waist circumference/height [WC/height], body fat mass percentage, and body lean mass percentage) by egg consumption categories (<1 egg/week, 1-4 eggs/week, ≥5 eggs/week). Hayes's PROCESS macro was used for mediation analyses.

RESULTS

Participants reporting high egg consumption (≥5 eggs/week) showed significantly lower BMI, WC/height and body fat mass percentage values and higher body lean mass percentage values than those reporting low egg consumption (<1 egg/week) (p < 0.05). However, these relationships were not maintained after adjusting for protein intake. Protein intake acted as a full mediator of the relationships of egg consumption with BMI (indirect effect [IE] = -1.19; 95% CI [-3.33; -0.36]), WC/height (IE = -0.01; 95% CI [-0.04; -0.01]) and body lean mass percentage (IE = 2.99; 95% CI [1.26; 5.73]) as a partial mediator of the relationship be-tween egg consumption and body fat mass percentage (IE = -2.19; 95% CI [-4.92; -0.46]).

CONCLUSIONS

The association between egg consumption and body composition is mediated by protein intake. This finding is important from a public health perspective, suggesting that higher egg consumption (≥5 eggs/week) may lead to a healthier body composition, especially due to higher protein intake.

Higher protein intake during caloric restriction improves diet quality and attenuates loss of lean body mass

OBJECTIVE

Higher protein intake during weight loss is associated with better health outcomes, but whether this is because of improved diet quality is not known. The purpose of this study was to examine how the change in self-selected protein intake during caloric restriction (CR) alters diet quality and lean body mass (LBM).

METHODS

In this analysis of pooled data from multiple weight loss trials, 207 adults with overweight or obesity were examined before and during 6 months of CR (approximately 10 food records/person). Body composition was measured by dual-energy x-ray absorptiometry. Diet quality was assessed using the Healthy Eating Index in 2 groups: lower (LP) and higher (HP) protein intake.

RESULTS

Participants (mean [SD], 54 [11] years; 29 [4] kg/m² ) lost 5.0% (5.4%) of weight. Protein intake was 79 (9) g/d (1.0 [0.2] g/kg/d) and 58 (6) g/d (0.8 [0.1] g/kg/d) in the HP and LP groups, respectively (p < 0.05), and there was an attenuated LBM (kilograms) loss in the HP (-0.6% [1.5%]) compared with the LP (-1.2% [1.4%]) group (p < 0.01). The increased Healthy Eating Index score in the HP compared with the LP group was attributed to greater total protein and green vegetable intake and reduced refined grain and added-sugar intake (p < 0.05).

CONCLUSIONS

Increasing dietary protein during CR improves diet quality and may be another reason for reduced LBM, but it requires further study.

Ketogenic diets, physical activity and body composition: a review

Obesity remains a serious relevant public health concern throughout the world despite related countermeasures being well understood (i.e. mainly physical activity and an adjusted diet). Among different nutritional approaches, there is a growing interest in ketogenic diets (KD) to manipulate body mass (BM) and to enhance fat mass loss. KD reduce the daily amount of carbohydrate intake drastically. This results in increased fatty acid utilisation, leading to an increase in blood ketone bodies (acetoacetate, 3-β-hydroxybutyrate and acetone) and therefore metabolic ketosis. For many years, nutritional intervention studies have focused on reducing dietary fat with little or conflicting positive results over the long term. Moreover, current nutritional guidelines for athletes propose carbohydrate-based diets to augment muscular adaptations. This review discusses the physiological basis of KD and their effects on BM reduction and body composition improvements in sedentary individuals combined with different types of exercise (resistance training or endurance training) in individuals with obesity and athletes. Ultimately, we discuss the strengths and the weaknesses of these nutritional interventions together with precautionary measures that should be observed in both individuals with obesity and athletic populations. A literature search from 1921 to April 2021 using Medline, Google Scholar, PubMed, Web of Science, Scopus and Sportdiscus Databases was used to identify relevant studies. In summary, based on the current evidence, KD are an efficient method to reduce BM and body fat in both individuals with obesity and athletes. However, these positive impacts are mainly because of the appetite suppressive effects of KD, which can decrease daily energy intake. Therefore, KD do not have any superior benefits to non-KD in BM and body fat loss in individuals with obesity and athletic populations in an isoenergetic situation. In sedentary individuals with obesity, it seems that fat-free mass (FFM) changes appear to be as great, if not greater, than decreases following a low-fat diet. In terms of lean mass, it seems that following a KD can cause FFM loss in resistance-trained individuals. In contrast, the FFM-preserving effects of KD are more efficient in endurance-trained compared with resistance-trained individuals.

Effects of the ketogenic diet on performance and body composition in athletes and trained adults: a systematic review and Bayesian multivariate multilevel meta-analysis and meta-regression

This systematic review with meta-analysis aimed to determine the effects of the ketogenic diet (KD) against carbohydrate (CHO)-rich diets on physical performance and body composition in trained individuals. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and The Cochrane Library were searched. Randomized and non-randomized controlled trials in athletes/trained adults were included. Meta-analytic models were carried out using Bayesian multilevel models. Eighteen studies were included providing estimates on cyclic exercise modes and strength one-maximum repetition (1-RM) performances and for total, fat, and free-fat masses. There were more favorable effects for CHO-rich than KD on time-trial performance (mode [95% credible interval]; -3.3% [-8.5%, 1.7%]), 1-RM (-5.7% [-14.9%, 2.6%]), and free-fat mass (-0.8 [-3.4, 1.9] kg); effects were more favorable to KD on total (-2.4 [-6.2, 1.8] kg) and fat mass losses (-2.4 [-5.4, 0.2] kg). Likely modifying effects on cyclic performance were the subject's sex and VO2max, intervention and performance durations, and mode of exercise. The intervention duration and subjects' sex were likely to modify effects on total body mass. KD can be a useful strategy for total and fat body losses, but a small negative effect on free-fat mass was observed. KD was not suitable for enhancing strength 1-RM or high-intensity cyclic performances.

Postmenopausal women with high TNF-α concentrations presented less reduction in fat and blood lipids

Aims: evaluate the effects of a high-protein diet associated with physical exercise on inflammatory markers and body composition. Methods: the study is a 12-week clinical trial of 26 postmenopausal women who received an individualized high-protein food plan and participated in three multicomponent training sessions each week. Food intake was monitored through eight 24-hour food recalls, and the habitual food intake was estimated. At the beginning and end of the study, anthropometric variables were measured; fat content and lean mass were estimated using formulas, and blood was collected for C-reactive protein (CRP) quantification, including TNF-α, IL-6, IL-10, and IL-18. One-way ANOVA was performed.Results: it was identified that 13 participants had a high-protein (HP) diet and 13 had a standard-protein (SP) diet. The HP group lost weight (p = 0.032); however, there were no changes in the fat content, the lean mass content, or the inflammatory markers. Only women who started the program with lower TNF-α values showed significant loss of total fat (p = 0.049), visceral fat (p = 0.037), triglycerides (p = 0.031), and LDL cholesterol (p = 0.003). Conclusion: postmenopausal women with high concentrations of inflammatory markers are less responsive to strategies for modifying body composition. 

Changes in 24-h energy expenditure, substrate oxidation, and body composition following resistance exercise and a high protein diet via whey protein supplementation in healthy older men

PURPOSE

To investigate changes in 24-h energy expenditure (EE), substrate oxidation, and body composition following resistance exercise (RE) and a high protein diet via whey protein supplementation (alone and combined) in healthy older men.

METHODS

In a pooled groups analysis, 33 healthy older men [(mean ± SE) age: 67 ± 1 years; BMI: 25.4 ± 0.4 kg/m2] were randomized to either RE (2×/week; n = 17) or non-exercise (n = 16) and either a high protein diet via whey protein supplementation (PRO, 2 × 25 g whey protein isolate/d; n = 17) or control (CON, 2 × 23.75 g maltodextrin/d; n = 16). An exploratory sub-analysis was also conducted between RE+CON (n = 8) and RE+PRO (n = 9). At baseline and 12 weeks, participants resided in respiration chambers for measurement of 24-h EE and substrate oxidation and wore an accelerometer for 7 days for estimation of free-living EE.

RESULTS

Resistance exercise resulted in greater increases in fat-free mass (1.0 ± 0.3 kg), resting metabolic rate [(RMR) 36 ± 14 kcal/d], sedentary EE (60 ± 33 kcal/d), and sleeping metabolic rate [(SMR) 45 ± 7 kcal/d] compared to non-exercise (p < 0.05); however, RE decreased activity energy expenditure in free-living (-90 ± 25 kcal/d; p = 0.049) and non-exercise activity inside the respiration chamber (-1.9 ± 1.1%; p = 0.049). PRO decreased fat mass [(FM) -0.5 ± 0.3 kg], increased overnight protein oxidation (30 ± 6 g/d), and decreased 24-h protein balance (-20 ± 4 g/d) greater than CON (p < 0.05). RE+PRO decreased FM (-1.0 ± 0.5 kg) greater than RE+CON (p = 0.04).

CONCLUSION

Resistance exercise significantly increased RMR, SMR, and sedentary EE in healthy older men, but not total EE. PRO alone and combined with RE decreased FM and aided body weight maintenance. This study was registered at clinicaltrials.gov as NCT03299972.

Effect of Dietary Weight Loss and Macronutrient Intake on Body Composition and Physical Function in Adults with Knee Osteoarthritis: A Systematic Review

Overweight and obesity increase the risk of development and progression of knee osteoarthritis (OA), with higher levels of fat mass and lower levels of lean mass associated with poorer functional status. The aim was to assess changes in weight, body composition and physical function following weight loss or weight maintenance interventions in knee OA. A comprehensive search of four databases was conducted. The risk of bias was assessed using the Quality Criteria Checklist for primary research. Primary outcomes included weight, body composition and physical function; secondary outcomes were lipids, inflammatory biomarkers and muscle strength. Eleven studies were included utilizing diet and exercise (n = 4) or diet-only (n = 7) interventions, two of which were weight maintenance studies. Most studies (n = 10) reported improvements in physical function with significant weight loss, while the change in strength reported in three studies was variable. The diet and exercise studies reported an average reduction in weight of 6.7% and lean mass of 1.6 kg, with greater improvements in physical function. The diet-only studies, including weight maintenance interventions, reported greater average weight loss (7.8%) and reduction in LM (2.0 kg). Overall, better retention of lean mass and muscle strength was observed in participants with higher protein intake (≥37% of energy) and subsequently improved physical function.

Do gluten peptides stimulate weight gain in humans?

Observations from animal and in vitro laboratory research, and anecdotal evidence, have led to the suggestion that gluten consumption stimulates weight gain by the presence of peptides expressing opioid activity. Another proposed mechanism is that gluten peptides decrease resting energy expenditure resulting in a positive energy balance. In order to induce such effects in vivo, intact food peptides must be absorbed in sufficient quantities, remain intact in the blood for sufficient time to have long-lasting biological activity and bind to receptors involved in appetite, satiety and energy regulation. However, although peptides from food may pass from the intestine into the blood in extremely low quantities, they are generally rapidly degraded by plasma and vasculum-bound aminopeptidases, resulting in very short half-lives and loss of bioactivity. At present, gluten peptide sequences that influence regulators of energy metabolism have not been identified. Furthermore, data on the quantitative absorption of gluten peptides in the blood stream, their stability and lasting bioactivity are also lacking. Therefore, there is no evidence for proposed effects on driving appetite by the brain, nor on energy expenditure and weight gain. Furthermore, the level of overweight observed in various countries appears to be independent of the level of wheat consumption, and abundant observational evidence in humans shows that the levels of gluten consumption are neither related to daily calorie intake nor to BMI. This narrative review therefore discusses the proposed effects of gluten on bodyweight (BW) and putative biological mechanisms in the light of the current evidence.

Effects of Dietary Protein Source and Quantity on Bone Morphology and Body Composition Following a High-Protein Weight-Loss Diet in a Rat Model for Postmenopausal Obesity

Higher protein (>30% of total energy, HP)-energy restriction (HP-ER) diets are an effective means to improve body composition and metabolic health. However, weight loss (WL) is associated with bone loss, and the impact of HP-ER diets on bone is mixed and controversial. Recent evidence suggests conflicting outcomes may stem from differences in age, hormonal status, and the predominant source of dietary protein consumed. Therefore, this study investigated the effect of four 12-week energy restriction (ER) diets varying in predominate protein source (beef, milk, soy, casein) and protein quantity (normal protein, NP 15% vs. high, 35%) on bone and body composition outcomes in 32-week-old obese, ovariectomized female rats. Overall, ER decreased body weight, bone quantity (aBMD, aBMC), bone microarchitecture, and body composition parameters. WL was greater with the NP vs. HP-beef and HP-soy diets, and muscle area decreased only with the NP diet. The HP-beef diet exacerbated WL-induced bone loss (increased trabecular separation and endocortical bone formation rates, lower bone retention and trabecular BMC, and more rod-like trabeculae) compared to the HP-soy diet. The HP-milk diet did not augment WL-induced bone loss. Results suggest that specific protein source recommendations may be needed to attenuate the adverse alterations in bone quality following an HP-ER diet in a model of postmenopausal obesity.

Associations of physical activity with sarcopenia and sarcopenic obesity in middle-aged and older adults: the Louisiana osteoporosis study

BACKGROUND

This study examined the associations between physical activity, obesity, and sarcopenia in middle-aged and older adults.

METHODS

We analyzed the data of 8, 919 study participants aged between 45 to 97 (mean age = 57.2 ± 8.8) from a Southern state in the United States. Self-reported physical activity was classified to regular exercise ≥ 3 times/week, < 3 times/week, and no regular exercise. Associations between physical activity, obesity and sarcopenia were explored with generalized linear models and ordinal logistic regressions stratified by age (middle-aged and older adults) and gender adjusting for covariates.

RESULTS

In middle-aged and older adults, all examined obesity related traits (e.g., body mass index, waist circumference) were inversely associated with physical activity levels (p < 0.01) in both genders. Exercising ≥ 3 times/week was negatively associated with lean mass indicators (e.g., appendicular lean mass) in middle-aged and older females (p < 0.01), while the negative associations become positive after adjusting for weight. Positive associations between physical activity and grip strength were only found in middle-aged males (p < 0.05). Ordinal logistic regression revealed that those exercising ≥ 3 times/week were less likely to have obesity, sarcopenia, and sarcopenia obesity in all groups (p < 0.01), except for sarcopenia in older males and females (p > 0.05). Positive associations of exercising < 3 times/week with sarcopenia and sarcopenia obesity were only found in middled adults.

CONCLUSION

The associations of exercise frequency with obesity and sarcopenia vary considerably across gender and age groups. Exercise programs need to be individualized to optimize health benefits. Future research exploring physical activity strategies to balance weight reduction and lean mass maintaining is warranted in middle-aged and especially older adults.

Moderate and Higher Protein Intakes Promote Superior Body Recomposition in Older Women Performing Resistance Training

PURPOSE

Resistance training (RT) combined with appropriate dietary intake can promote a concomitant increase in skeletal muscle mass (SMM) and reduction in fat mass, a condition termed body recomposition. This study's primary purpose was to explore the effects of protein ingestion on body recomposition after 24 wk of RT in older women.

METHODS

Data from 130 untrained older women (68.7 ± 5.6 yr, 66.5 ± 11.5 kg, 155.5 ± 6.0 cm, and 27.4 ± 4.0 kg·m-2) across six studies were retrospectively analyzed. The participants were divided into tertiles according to their customary protein intake (g·kg-1·d-1): lower (LP; n = 45), moderate (MP; n = 42), and higher (HP; n = 43) protein intake. Participants performed a whole-body RT program carried out over 24 wk (eight exercises, three sets, 8-15 repetitions, three sessions a week). SMM and fat mass were determined by dual-energy x-ray absorptiometry.

RESULTS

All groups increased SMM from baseline (P < 0.05), with the HP and MP groups showing greater increases than the LP group (LP, 2.3%; MP, 5.4%; and HP, 5.1%; P < 0.05). Reductions in fat mass were similar for all three groups (LP, 1.7%; MP, 3.7%; and HP, 3.1%; P > 0.05). The composite z-score of the percentage changes from pretraining to posttraining indicated greater positive body recomposition values for HP and MP compared with LP (P < 0.05).

CONCLUSIONS

Results suggest that protein intake is a moderating variable for body recomposition in older women undergoing RT, with a low protein intake having a less favorable effect on body recomposition.

Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults

We performed a systematic review, meta-analysis, and meta-regression to determine if increasing daily protein ingestion contributes to gaining lean body mass (LBM), muscle strength, and physical/functional test performance in healthy subjects. A protocol for the present study was registered (PROSPERO, CRD42020159001), and a systematic search of Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Only randomized controlled trials (RCT) where participants increased their daily protein intake and were healthy and non-obese adults were included. Research questions focused on the main effects on the outcomes of interest and subgroup analysis, splitting the studies by participation in a resistance exercise (RE), age (<65 or ≥65 years old), and levels of daily protein ingestion. Three-level random-effects meta-analyses and meta-regressions were conducted on data from 74 RCT. Most of the selected studies tested the effects of additional protein ingestion during RE training. The evidence suggests that increasing daily protein ingestion may enhance gains in LBM in studies enrolling subjects in RE (SMD [standardized mean difference] = 0.22, 95% CI [95% confidence interval] 0.14:0.30, P < 0.01, 62 studies, moderate level of evidence). The effect on LBM was significant in subjects ≥65 years old ingesting 1.2-1.59 g of protein/kg/day and for younger subjects (<65 years old) ingesting ≥1.6 g of protein/kg/day submitted to RE. Lower-body strength gain was slightly higher by additional protein ingestion at ≥1.6 g of protein/kg/day during RE training (SMD = 0.40, 95% CI 0.09:0.35, P < 0.01, 19 studies, low level of evidence). Bench press strength is slightly increased by ingesting more protein in <65 years old subjects during RE training (SMD = 0.18, 95% CI 0.03:0.33, P = 0.01, 32 studies, low level of evidence). The effects of ingesting more protein are unclear when assessing handgrip strength and only marginal for performance in physical function tests. In conclusion, increasing daily protein ingestion results in small additional gains in LBM and lower body muscle strength gains in healthy adults enrolled in resistance exercise training. There is a slight effect on bench press strength and minimal effect performance in physical function tests. The effect on handgrip strength is unclear.