Clinical Evidence and Mechanisms of High-Protein Diet-Induced Weight Loss

Common questions and misconceptions about protein supplementation: what does the scientific evidence really show?

Protein supplementation often refers to increasing the intake of this particular macronutrient through dietary supplements in the form of powders, ready-to-drink shakes, and bars. The primary purpose of protein supplementation is to augment dietary protein intake, aiding individuals in meeting their protein requirements, especially when it may be challenging to do so through regular food (i.e. chicken, beef, fish, pork, etc.) sources alone. A large body of evidence shows that protein has an important role in exercising and sedentary individuals. A PubMed search of "protein and exercise performance" reveals thousands of publications. Despite the considerable volume of evidence, it is somewhat surprising that several persistent questions and misconceptions about protein exist. The following are addressed: 1) Is protein harmful to your kidneys? 2) Does consuming "excess" protein increase fat mass? 3) Can dietary protein have a harmful effect on bone health? 4) Can vegans and vegetarians consume enough protein to support training adaptations? 5) Is cheese or peanut butter a good protein source? 6) Does consuming meat (i.e., animal protein) cause unfavorable health outcomes? 7) Do you need protein if you are not physically active? 8) Do you need to consume protein ≤ 1 hour following resistance training sessions to create an anabolic environment in skeletal muscle? 9) Do endurance athletes need additional protein? 10) Does one need protein supplements to meet the daily requirements of exercise-trained individuals? 11) Is there a limit to how much protein one can consume in a single meal? To address these questions, we have conducted a thorough scientific assessment of the literature concerning protein supplementation.

Milk protein concentrate supplementation improved appetite, metabolic parameters, adipocytokines, and body composition in dieting women with obesity: a randomized controlled trial

BACKGROUND

Dairy consumption is associated with many health benefits. However, to our knowledge, no clinical trials examined the effects of milk protein concentrate (MPC) on metabolic health in overweight and obese adults. This study investigated the effect of supplementation with MPC on glycaemic status, lipid profile, biomarkers of inflammation, and anthropometric measurements in women with obesity under a weight loss diet.

METHODS

This is a single-blind, open-labelled, parallel-group, randomized trial. Forty-four healthy women with obesity were randomized into a control (n = 22) or MPC (n = 22) group. Participants in the MPC group were supplemented with 30 g of MPC per day for 8 weeks. Both groups were on a calorie-restricted diet plan with 800 Kcal lower intakes than their needs. Blood samples, dietary intake, and body composition were assessed before and after the intervention.

RESULTS

MPC group had a significantly lower body mass index (P = 0.009), waist circumference (P = 0.013), fat mass (P = 0.021), appetite score (P = 0.002), fasting blood sugar (P < 0.001), insulin (P = 0.027), low-density lipoprotein cholesterol (P = 0.025), and leptin (P = 0.014) levels and higher high-density lipoprotein cholesterol (P = 0.001) and adiponectin (P = 0.032) compared to the control group after supplementation. Lean body mass, total cholesterol, and triglyceride did not differ significantly (P > 0.05).

CONCLUSION

Daily intake of 30 g of MPC for 8 weeks may improve several anthropometric and metabolic markers in women with obesity under a hypocaloric diet.

[Strategies for the prevention and non-pharmacological treatment of obesity. Models of care]

The prevalence of obesity has increased in recent years worldwide. In this context, strategies for management obesity in primary care are essential. The first step in the treatment of obesity are lifestyle intervention programs. The three pillars of these programs, ideally of high intensity (high frequency of visits), are dietary intervention, exercise and behavioral therapy. There is no universal model of care for patients with obesity, but it must take into account key aspects, such as facilitating the access and adherence of the patient and a multidisciplinary and coordinated care among professionals at different levels of healthcare. The components of the model of care and its format should be defined according to the resources available and the characteristics of the population to be treated.

Nutritional Considerations During Major Weight Loss Therapy: Focus on Optimal Protein and a Low-Carbohydrate Dietary Pattern

PURPOSE OF REVIEW

Considering the high prevalence of obesity and related metabolic impairments in the population, the unique role nutrition has in weight loss, reversing metabolic disorders, and maintaining health cannot be overstated. Normal weight and well-being are compatible with varying dietary patterns, but for the last half century there has been a strong emphasis on low-fat, low-saturated fat, high-carbohydrate based approaches. Whereas low-fat dietary patterns can be effective for a subset of individuals, we now have a population where the vast majority of adults have excess adiposity and some degree of metabolic impairment. We are also entering a new era with greater access to bariatric surgery and approval of anti-obesity medications (glucagon-like peptide-1 analogues) that produce substantial weight loss for many people, but there are concerns about disproportionate loss of lean mass and nutritional deficiencies.

RECENT FINDINGS

No matter the approach used to achieve major weight loss, careful attention to nutritional considerations is necessary. Here, we examine the recent findings regarding the importance of adequate protein to maintain lean mass, the rationale and evidence supporting low-carbohydrate and ketogenic dietary patterns, and the potential benefits of including exercise training in the context of major weight loss. While losing and sustaining weight loss has proven challenging, we are optimistic that application of emerging nutrition science, particularly personalized well-formulated low-carbohydrate dietary patterns that contain adequate protein (1.2 to 2.0 g per kilogram reference weight) and achieve the beneficial metabolic state of euketonemia (circulating ketones 0.5 to 5 mM), is a promising path for many individuals with excess adiposity.

Deciphering the complex interplay of obesity, epithelial barrier dysfunction, and tight junction remodeling: Unraveling potential therapeutic avenues

Obesity stands as a formidable global health challenge, predisposing individuals to a plethora of chronic illnesses such as cardiovascular disease, diabetes, and cancer. A confluence of genetic polymorphisms, suboptimal dietary choices, and sedentary lifestyles significantly contribute to the elevated incidence of obesity. This multifaceted health issue profoundly disrupts homeostatic equilibrium at both organismal and cellular levels, with marked alterations in gut permeability as a salient consequence. The intricate mechanisms underlying these alterations have yet to be fully elucidated. Still, evidence suggests that heightened inflammatory cytokine levels and the remodeling of tight junction (TJ) proteins, particularly claudins, play a pivotal role in the manifestation of epithelial barrier dysfunction in obesity. Strategic targeting of proteins implicated in these pathways and metabolites such as short-chain fatty acids presents a promising intervention for restoring barrier functionality among individuals with obesity. Nonetheless, recognizing the heterogeneity among affected individuals is paramount; personalized medical interventions or dietary regimens tailored to specific genetic backgrounds and allergy profiles may prove indispensable. This comprehensive review delves into the nexus of obesity, tight junction remodeling, and barrier dysfunction, offering a critical appraisal of potential therapeutic interventions.

A dairy-based, protein-rich breakfast enhances satiety and cognitive concentration before lunch in overweight to obese young females: A randomized controlled crossover study

The purpose of this study was to investigate if consumption of a high-protein, low-carbohydrate breakfast (PRO) leads to a lower subsequent ad libitum energy intake at lunch and the rest of the day compared with ingestion of an isocaloric low-protein, high-carbohydrate breakfast (CHO) or no breakfast (CON). The study was designed as a randomized controlled 3-period crossover study. Thirty young (18-30 yr) females with overweight to obesity (body mass index >25 kg/m2) in random order completed 3 separate experimental days where they consumed either a PRO, CHO, or CON breakfast test meal followed by an ad libitum lunch meal 3 h after breakfast. Participants were allocated to a sequence group by their inclusion number. The PRO and CHO breakfasts were matched in dietary fiber and fat content. Energy intake at lunch was calculated and dietary records were obtained for the rest of the day to calculate the total daily energy intake and macronutrient intake. Ratings of appetite sensations between meals and palatability of the test meals were assessed using visual analog scale sheets in intervals ranging from 10 to 30 min. In addition, blood samples were obtained at multiple time points separated by 10 to 60 min intervals between breakfast and lunch and were analyzed for appetite-regulating gut hormones, insulin, and glucose. Finally, performance in a cognitive concentration test was tested 150 min after breakfast. Compared with CHO and CON, the area under the curves for satiety, fullness, and satisfaction in the 3 h after breakfast were significantly higher after PRO, whereas the areas under the curve for hunger, desire to eat, and prospective eating were significantly lower after PRO. The appetite-regulating gut hormones cholecystokinin, glucagon-like peptide-1, and ghrelin in the hours after breakfast, energy intake during the ad libitum lunch meal, and the total daily energy intake did not differ significantly between PRO, CHO, and CON. However, the cognitive concentration test score was 3.5 percentage points higher for PRO, but not CHO, versus CON. A dairy-based high-protein, low-carbohydrate breakfast increased satiety sensation in the hours after breakfast but did not reduce total daily energy intake compared with an isocaloric low-protein, high-carbohydrate breakfast or omitting breakfast. However, performance in a cognitive concentration test before lunch was enhanced after the high-protein, low-carbohydrate breakfast, but not the low-protein, high-carbohydrate breakfast, compared with omitting breakfast.

A Narrative Review of the Significance of Popular Diets in Diabetes Mellitus Management

Diabetes mellitus is a collection of metabolic disorders marked by elevated levels of glucose in the blood due to irregularities in the generation or functioning of insulin. Medical nutrition therapy and weight loss are crucial elements in the management of diabetes and the prevention of complications. Several diets have become popular over time for the goal of achieving weight loss, but their popularity has declined due to a lack of reliable scientific evidence. This study classifies popular diets into three categories: diets that manage the composition of macronutrients, diets that restrict specific foods or food groups, and diets that manipulate meal timing. The review includes research studies that investigated the effects of popular diets on the prevention, management, and complications of diabetes. It is clear that different popular diets can have positive effects on both preventing and treating diabetes and preventing and treating complications related to diabetes. However, it is not practical to determine which diet is the most effective option for preventing or controlling diabetes. Thus, the main focus should be on common underlying factors that support well-being, such as decreasing the intake of refined grains and added sugar, choosing non-starchy vegetables, and giving priority to whole foods over processed foods whenever possible, until there is stronger evidence supporting the specific benefits of different dietary patterns.

High-protein high-konjac glucomannan diets changed glucose and lipid metabolism by modulating colonic microflora and bile acid profiles in healthy mouse models

High protein and fiber diets are becoming increasingly popular for weight loss; however, the benefits or risks of high protein and fiber diets with a normal calorie level for healthy individuals still need to be elucidated. In this study, we explored the role and mechanisms of long-term high protein and/or konjac glucomannan diets on the metabolic health of healthy mouse models. We found that high konjac glucomannan contents improved the glucose tolerance of mice and both high protein and high konjac glucomannan contents improved the serum lipid profile but increased the TNF-α levels. In the liver, high dietary protein contents reduced the expression of the FASN gene related to fatty acid synthesis. Interactions of dietary protein and fiber were shown in the signaling pathways related to lipid and glucose metabolism of the liver and the inflammatory status of the colon, wherein the high protein and high konjac glucomannan diet downregulated the expression of the SREBF1 and FXR genes in the liver and downregulated the expression of TNF-α genes in the colon compared to the high protein diet. High konjac glucomannan contents reduced the colonic secondary bile acid levels including DCA and LCA; this was largely associated with the changed microbiota profile and also contributed to improved lipid and glucose homeostasis. In conclusion, high protein diets improved lipid homeostasis and were not a risk to metabolic health, while high fiber diets improved glucose and lipid homeostasis by modulating colonic microbiota and bile acid profiles, and a high protein diet supplemented with konjac glucomannan might improve hepatic lipid homeostasis and colonic inflammation in healthy mouse models through long-term intervention.

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.

A systematic review of the effect of semaglutide on lean mass: insights from clinical trials

INTRODUCTION

Semaglutide, a glucagon-like peptide-1 receptor agonist, is associated with significant weight loss, yet its impact on lean body mass remains insufficiently understood. This review investigates the effect of semaglutide on lean mass in the context of obesity management.

METHODOLOGY

This study investigates through different databases (PubMed, Elsevier, and Google Scholar) from 2016 for randomized control trials (RCTs) or observational studies that assessed the use of semaglutide in overweight or obese patients, regardless of whether they have type 2 diabetes or not. The studies compared semaglutide to a placebo or alternative medications.

RESULTS

Six studies with 1,541 overweight or obese adults were included, and significant weight reductions were observed primarily due to fat mass loss. While the lean mass remained stable in some cases, notable reductions ranging from almost 0% to 40% of total weight reduction were observed in others. Noteworthy decreases in lean mass were particularly evident in larger trials, yet the proportion of lean mass relative to total body mass increased, suggesting a positive overall outcome.

CONCLUSION

Semaglutide displays potential for weight loss primarily through fat mass reduction. However, concerns arise from notable reductions in lean mass, especially in trials with a larger number of patients.

Associations between ultraprocessed and minimally processed snacks consumption and overweight/obesity among college students in South Florida

OBJECTIVE

Evaluate the association between ultraprocessed and minimally processed snack consumption and overweight/obesity among college students.

PARTICIPANTS

College students.

METHODS

Cross-sectional study. Participants completed an online survey with questions on socio-demographics, beverages and snacks consumption, and weight status. ANCOVA and logistic regression was used; analyses were adjusted for age, sex, race/ethnicity, physical activity, and sleep duration.

RESULTS

A total of 435 students completed all questions in the survey. Most students were female (73.3%), Hispanics (61.1%), had a mean age of 24.7-year old and 40% had overweight/obesity. Those with overweight/obesity also had higher odds of consuming soft drinks in higher frequency and quantity than those without overweight/obesity (p < .05). Never consuming unsweetened yogurt/cheese and lower frequency and consumption of fruits were associated with higher odds of overweight/obesity (p < .05).

CONCLUSION

Higher frequency and consumption of soft drinks while lower frequency and consumption of unsweetened yogurt/cottage cheese and fruits were associated with overweight/obesity.

Fried food consumption, genetic risk, and incident obesity: a prospective study

Background and aims: Genetic and dietary factors contribute to adiposity risk, but little evidence supports genetic personalization of fried food intake recommendations for the management of obesity. This study aimed to assess the associations between fried food consumption and adiposity incidence and whether the associations were modified by an individual's genotype. Methods: We included 27 427 participants who had dietary data assessed by a validated 24 h dietary recall and available anthropometric information from the UK Biobank study. The genetic risk score (GRS) was calculated using 940 BMI associated variants. Results: With an average of 8.1 years of follow-up, 1472 and 2893 participants were defined as having overall obesity and abdominal obesity, respectively. Individuals in the highest categories of fried food consumption were positively associated with the risk of obesity (HR = 1.31; 95% CI 1.10-1.56) and abdominal obesity (HR = 1.27; 95% CI 1.12-1.45) compared with the lowest categories. Moreover, fried food consumption had a significant interatction with obesity GRS for abdominal obesity risk (P interaction = 0.016). Fried food intake was associated with a higher abdominal obesity risk (HR = 1.59, 95% CI: 1.25-2.00) among participants with a lower genetic risk. Conclusions: Our findings indicated that fried food consumption had a higher abdominal obesity risk among individuals with a lower genetic risk, suggesting the restriction of fried food intake for this group of people.

What could be the reasons for not losing weight even after following a weight loss program?

INTRODUCTION

Approximately four million people worldwide die annually because of obesity. Weight loss is commonly recommended as a first-line therapy in overweight and obese patients. Although many individuals attempt to lose weight, not everyone achieves optimal success. Few studies point out that weight loss eventually slows down, stagnates or reverses in 85% of the cases.

RESEARCH QUESTION

What could be the reasons for not losing weight even after following a weight loss program?

METHODS

A scoping review of the literature was performed using weight loss-related search terms such as 'Obesity,' 'Overweight,' 'Lifestyle,' 'weight loss,' 'Basal Metabolism,' 'physical activity,' 'adherence,' 'energy balance,' 'Sleep' and 'adaptations. The search involved reference tracking and database and web searches (PUBMED, Science Direct, Elsevier, Web of Science and Google Scholar). Original articles and review papers on weight loss involving human participants and adults aged > 18 years were selected. Approximately 231 articles were reviewed, and 185 were included based on the inclusion criteria.

DESIGN

Scoping review.

RESULTS

In this review, the factors associated with not losing weight have broadly been divided into five categories. Studies highlighting each subfactor were critically reviewed and discussed. A wide degree of interindividual variability in weight loss is common in studies even after controlling for variables such as adherence, sex, physical activity and baseline weight. In addition to these variables, variations in factors such as previous weight loss attempts, sleep habits, meal timings and medications can play a crucial role in upregulating or downregulating the association between energy deficit and weight loss results.

CONCLUSION

This review identifies and clarifies the role of several factors that may hinder weight loss after the exploration of existing evidence. Judging the effectiveness of respective lifestyle interventions by simply observing the 'general behavior of the groups' is not always applicable in clinical practice. Each individual must be monitored and advised as per their requirements and challenges.

Microalgae: potential novel protein for sustainable human nutrition

To support a global population of ~10 billion people in 2050, dietary protein demand is forecast to increase 32-78% compared to 2017, requiring significantly higher planetary resources. Microalgae are an attractive sustainable protein source compared with current plant and animal sources. Benefits include mass scalability, low CO2 emissions, and significantly reduced land and freshwater use per unit protein. Microalgae are already used as food products and numerous species exhibit high total protein contents and well-balanced essential amino acid (EAA) compositions for human dietary requirements. Microalgae proteins are also bioavailable for human digestion, and downstream processing steps are likely to further enhance protein digestibility. Species, cultivation, and process/product optimisation are actively being developed to enhance their nutritional, social, and environmental benefits.

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Higher Imported Food Patterns Are Associated with Obesity and Severe Obesity in Tuvalu: A Latent Class Analysis

Background

Tuvalu is a Pacific Island country within the small island developing states that has observed a significant and alarming increase in obesity rates over the past 40 years, affecting ∼60 %-70 % of the current population.

Objectives

This study aimed to investigate the association between food patterns and the proportion of obesity in a Pacific Island country.

Methods

The 2022 COMmunity-based Behavior and Attitude survey in Tuvalu (COMBAT) included 985 adults with complete data on sociodemographic information and the frequency of consumption of 25 common foods. A latent class analysis determined 4 food patterns. Bayesian multilevel logistic and linear regression models estimated the association between food patterns and the proportion of obesity [body mass index (BMI) ≥30 kg/m2], severe obesity (BMI ≥40 kg/m2), and weight (kg), adjusting for potential confounders and accounting for clustering by region.

Results

The latent class analysis revealed 4 food patterns with an entropy of 0.94 and an average posterior probability of class assignment for each individual of 0.97, described as follows: 1) local: locally produced foods with moderate food diversity (proportion of individuals = 28 %); 2) diverse-local: local with greater food diversity (17 %); 3) restricted-imported: more imported with restricted diversity (29 %); and 4) imported: heavily imported with high diversity (26 %). Compared to those following the diverse-local pattern, the odds of having obesity were greater for those classified with the imported pattern [odds ratio (OR): 2.52; 95 % credible interval (CrI): 1.59, 3.99], restricted-imported pattern (OR: 1.89; 95 % CrI: 1.59, 3.99), and local pattern (OR: 1.54; 95 % CrI: 0.94, 2.50). Similar trends were observed for severe obesity while body weight was positively associated with both restricted-imported and imported food patterns.

Conclusions

The high consumption of imported foods, together with the low consumption of plant-based foods and protein-rich foods, could be a relevant modifiable lifestyle factor explaining the high levels of obesity and severe obesity in Tuvalu, a Pacific Island country.

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".

Anorexia Nervosa With Intermittent Fever Due to Diet-Induced Thermogenesis: A Case Report

Diet-induced thermogenesis, influenced primarily by protein intake, generates energy from food. Herein, we present the case of anorexia nervosa in a 30-year-old woman, who developed intermittent fever while transitioning from continuous to intermittent tube feeding, with an increase in protein intake. Extensive investigations ruled out infection- or drug-related causes, indicating that intermittent fever resulted from diet-induced thermogenesis due to high protein administration. Recognizing the potential for diet-induced thermogenesis in cases of fever during tube feeding is crucial to avoid unnecessary antibiotic use and prevent the discontinuation of essential medications.

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.

Protein - a scoping review for Nordic Nutrition Recommendations 2023

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body's needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

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.

Protein and amino acids in obesity: friends or foes?

PURPOSE OF REVIEW

Nutritional interventions using protein and amino acids in obesity are popular therapeutical strategies to limit obesity development. However, the effects of dietary protein intake and amino acid metabolic alterations involved in obesity pathophysiology have not been completely unravelled. Significant recent studies have brought to light new findings in these areas, which are the primary focus of this review.

RECENT FINDINGS

We describe the effects of protein intake on weight regain prevention, the influence on gut microbiota, the response to low-protein highly processed foods, and the contrasting impacts of a high-protein diet on adults and children. We also explore newly discovered correlations between amino acids, liver fat accumulation, and the dysregulation of the liver-pancreas axis due to alterations in amino acid levels in the context of obesity. Lastly, we consider branched-chain amino acids, along with glycine and tryptophan, as significant biomarkers during periods of positive or negative energy balance.

SUMMARY

Interventions using dietary protein in obesity may be useful, especially during energy restriction but also in sarcopenic obesity. Furthermore, metabolic profiles that encompass alterations in certain amino acids can provide valuable insights into the metabolic condition of patients with obesity, particularly in relation to insulin resistance and the risk of developing type 2 diabetes.

Exploring high-protein diets in the context of cardiac rehabilitation

The review aims to explore the potential benefit and risk of high-protein diets (HPD) regarding the comorbidity of sarcopoenia and CVD in the setting of cardiac rehabilitation (CR). CR is standard care for individuals who have experienced a cardiac event, but the current practice of predominantly aerobic exercise, a lower-fat diet and weight loss poorly addresses the issue of sarcopoenia. HPD, especially when combined with resistance exercise (RE), may be valuable adjuncts to current CR practice and benefit both muscle and cardiovascular health. Meta-analyses and randomised controlled trials of HPD and CVD risk show beneficial but variable effects regarding weight loss, the lipid profile, insulin resistance and lean body mass in those living with or high risk of CVD. Meta-analyses of prospective cohort studies on hard CVD endpoints favour lower- and plant-protein diets over higher animal protein, but the evidence is inconsistent. HPD augment the strength and muscle gaining benefits of RE in older populations, but there are no published data in those living with CVD providing promising opportunities for CR research. HPD raise concern regarding renal and bone health, the microbiome, branched chain amino acids and environmental sustainability and findings suggest that plant-based HPD may confer ecological and overall health advantages compared to animal-based HPD. However, incorporating RE with HPD might alleviate certain health risks. In conclusion, a largely plant-based HPD is deemed favourable for CR when combined with RE, but further research regarding efficacy and safety in CR populations is needed.

Benefits of Chronic Administration of a Carbohydrate-Free Diet on Biochemical and Morphometric Parameters in a Rat Model of Diet-Induced Metabolic Syndrome

Carbohydrate intake restriction positively affects markers related to metabolic syndrome (MS). However, the effects of long-term carbohydrate-free diets (CFD) have yet to be studied. The main objective of this study was to report the effects on biochemical and morphometric parameters in a rat model of MS. Male Wistar rats were initially divided into two groups: the standard diet group (SD, n = 20); and the MS group (n = 30) fed a high-glucose diet. Ten animals from each group were sacrificed after 20 weeks on their respective diets to verify MS development. The remaining MS animals were divided into two subgroups: one continued with the MS diet (n = 10); and the other transitioned to a carbohydrate-free diet (MS + CFD group, n = 10) for 20 more weeks. At week 40, parameters, including glucose, insulin, lipid profile, ketone bodies, C-reactive protein (CRP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, creatinine, liver and muscle glycogen, and serum, hepatic, renal, and pancreatic malondialdehyde (MDA) levels were assessed. Transitioning to CFD resulted in decreased caloric intake and body weight, with normalized parameters including MDA, insulin, lipid profile, ALT, liver glycogen, creatinine, and CRP levels. This shift effectively reversed the MS-induced alterations, except for glycemia and uremia, likely influenced by the diet's high protein content stimulating gluconeogenesis. This research underscores the potential benefits of long-term carbohydrate restriction in mitigating MS-related markers.

The Role of Artificial Intelligence in Deciphering Diet-Disease Relationships: Case Studies

Modernization of society from a rural, hunter-gatherer setting into an urban and industrial habitat, with the associated dietary changes, has led to an increased prevalence of cardiometabolic and additional noncommunicable diseases, such as cancer, inflammatory bowel disease, and neurodegenerative and autoimmune disorders. However, while dietary sciences have been rapidly evolving to meet these challenges, validation and translation of experimental results into clinical practice remain limited for multiple reasons, including inherent ethnic, gender, and cultural interindividual variability, among other methodological, dietary reporting-related, and analytical issues. Recently, large clinical cohorts with artificial intelligence analytics have introduced new precision and personalized nutrition concepts that enable one to successfully bridge these gaps in a real-life setting. In this review, we highlight selected examples of case studies at the intersection between diet-disease research and artificial intelligence. We discuss their potential and challenges and offer an outlook toward the transformation of dietary sciences into individualized clinical translation.

A Study on the Amelioration of Circadian Rhythm Disorders in Fat Mice Using High-Protein Diets

This innovative study investigates the effects of high-protein diets (milk protein) on the circadian rhythm of hepatic lipid metabolism. We aimed to understand how high-protein interventions regulate biological clock genes, maintain lipid metabolism balance, and affect the circadian rhythm of antioxidant levels in vivo. We divided 120 SPF-class C57BL/6J mice into the control, high-fat/low-protein (HF-LP), and high-fat/high-protein (HF-HP) groups. Mice were sacrificed during active (2 a.m. and 8 a.m.) and rest periods (2 p.m. and 8 p.m.). In the HF-LP group, hepatic lipid anabolic enzymes were consistently expressed at high levels, while key lipolytic enzymes slowly increased after feeding with no significant diurnal differences. This led to an abnormal elevation in blood lipid levels, a slow increase in and low levels of superoxide dismutase, and a rapid increase in malondialdehyde levels, deviating from the diurnal trend observed in the control group. However, high-protein interventions in the HF-HP group restored lipid synthase activity and the expression of key catabolic enzymes, exhibiting a precise circadian rhythm. It also improved the lipid-metabolism rhythm, which was disrupted by the high-fat diet. Overall, high-protein interventions restored the expression of key enzymes involved in lipid metabolism, improving the lipid-metabolism rhythm, which was disrupted by the high-fat diet.

Effects of 12 weeks of low molecular collagen peptide supplementation on body composition in overweight Korean adults aged 50 years and older.. [DOI: 10.21203/rs.3.rs-3016558/v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

After the age of 50, their muscle mass gradually declines each year, and the lost muscle is often replaced by fat mass. Insufficient protein intake after middle age further accelerates this process. Previous studies that have used collagen as a supplementation, which accounts for about 30% of the body's protein, have combined it with resistance exercise. This study investigated the effects of collagen supplementation on body composition in individuals over the age of 50 (23≤BMI≤32), while maintaining their daily activity levels constant. Participants were assigned to either the collagen group (n=42) or the placebo group(n=42). Collagen supplementation (15g of collagen) and placebo product (xanthan gum) were offered. Bioactive Collagen Peptides, which is a type of low molecular weight collagen extracted from porcine raw materials, was used. Body composition was measured by bioelectrical impedance analysis and dual-energy X-ray absorptiometry. Blood samples were taken for analysis. Physical activities and dietary intake were measured by international physical activity questionnaire and a 3-day food record, respectively. 74 participants in the collagen group (n=37) and placebo group (n=37) were used in the final analysis. Physical activity and dietary intake showed no significant difference between the two groups. The collagen group showed a significant reduction in total body fat mass compared to the placebo group, as evidenced by both BIA (P=0.021) and DEXA (P=0.041) measurements. There were no significant differences in blood measurements between the two groups. Therefore, the intake of collagen supplementation after middle age may be used for preventing age related fat mass accumulation.

The PCOS puzzle: putting the pieces together for optimal care

Polycystic ovary syndrome (PCOS) is a multifaceted hormonal disorder that has significant ramifications for both women's reproductive and metabolic well-being. This analysis aims to offer a thorough comprehension of PCOS by investigating the various contributing factors that are crucial for its effective management. We delve into the topic of hormonal imbalances, such as elevated androgens and disrupted estrogen-progesterone dynamics, and their effects on reproductive and metabolic health. Furthermore, we explore the intricate connection between insulin resistance, hyperinsulinemia, and PCOS, highlighting their pivotal role in metabolic dysfunction. Additionally, we examine fertility challenges, irregular menstrual patterns, and metabolic complications while also reviewing current treatment methodologies. Moreover, we address the latest research concerning genetic, environmental, and epigenetic influences on PCOS. By piecing together these essential elements, healthcare professionals can attain a comprehensive understanding of PCOS and deliver optimal care for those affected by the condition.

Obesity management in the Saudi population

Obesity is an alarming public health concern and needs to be addressed promptly in the Kingdom of Saudi Arabia. Sedentary lifestyle, changes in dietary intake and choice, culture, gender, climatic conditions and, lately, COVID-19 have contributed to obesity as a near epidemic in the Kingdom of Saudi Arabia. Interventions targeting obesity includes lifestyle management, pharmacotherapy, and surgery. Lifestyle interventions qualify as first-line therapies. Diets include a low-fat diet, low-calorie diet, low-carbohydrate diet, high-protein diet, and low-glycemic-index diet. Diet and exercise interventions can have a huge impact on weight loss. Pharmacotherapy is considered a treatment option at a later stage. Surgery is only for severely obese individuals. Above all, the government has to intervene and implement regulations and policies that can curb the incidence of obesity. This review aims to address obesity in the Kingdom of Saudi Arabia, interventions to curb it, and the impact of COVID-19 on obesity.

Effects of collagen supplementation on body composition and muscle strength in Korean adults aged 50 years and older.. [DOI: 10.21203/rs.3.rs-3016558/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

BACKGROUND: Insufficient protein intake can accelerate the loss of muscle mass as one ages. A decrease in muscle mass leads to an increase in fat mass, creating a vicious cycle that can result in sarcopenic obesity. Previous studies that have used collagen as a supplementation, which accounts for about 30% of the body's protein, have combined it with resistance exercise. OBJECTIVE: This study investigated the effects of collagen supplementation on body composition in individuals over the age of 50, while maintaining their daily activity levels constant. DESIGN: Double-blind randomized controlled trial PARTICIPANTS: Participants were assigned to either the collagen group (n=42) or the placebo group(n=42). MEASUREMENTS: Collagen supplementation (14g of collagen) and placebo product (xanthan gum) were offered to collagen group and placebo group respectively, once a day. Body composition was measured by bioelectrical impedance analysis and dual-energy X-ray absorptiometry. Participants were instructed to maintain their dietary intake and physical activity levels, which were evaluated through a 3-day food record analysis and an international physical activity questionnaire (IPAQ) analysis, respectively. RESULTS: 74 participants in the collagen group (n=37) and placebo group (n=37) completed the follow-up, and there was no significant difference between the two groups in terms of physical activity levels. The collagen group showed a significant reduction in total body fat mass compared to the placebo group, as evidenced by both BIA (P=0.021) and DEXA (P=0.041) measurements. However, there was no significant difference between the two groups in terms of muscle mass. Conclusion: From this study, the consumption of collagen supplementation is effective in reducing fat mass, which is significant in preventing sarcopenic obesity after middle age.

Effects of Animal and Vegetable Proteins on Gut Microbiota in Subjects with Overweight or Obesity

The gut microbiota plays a pivotal role in the balance between host health and obesity. The composition of the gut microbiota can be influenced by external factors, among which diet plays a key role. As the source of dietary protein is important to achieve weight loss and gut microbiota modulation, in the literature there is increasing evidence to suggest consuming more plant proteins than animal proteins. In this review, a literature search of clinical trials published until February 2023 was conducted to examine the effect of different macronutrients and dietary patterns on the gut microbiota in subjects with overweight and obesity. Several studies have shown that a higher intake of animal protein, as well as the Western diet, can lead to a decrease in beneficial gut bacteria and an increase in harmful ones typical of obesity. On the other hand, diets rich in plant proteins, such as the Mediterranean diet, lead to a significant increase in anti-inflammatory butyrate-producing bacteria, bacterial diversity and a reduction in pro-inflammatory bacteria. Therefore, since diets rich in fiber, plant protein, and an adequate amount of unsaturated fat may help to beneficially modulate the gut microbiota involved in weight loss, further studies are needed.

Soda intake influences phenotype, antioxidants and inflammatory status in high protein-fed wistar rats

An increasing population of people, especially young adults who exercise, consume high protein diets along with carbonated drinks. While there are numerous studies on the effect of high protein diets, there is a need to understand how protein diets in combination with carbonated drinks impact physiology. In order to assess these effects on wistar rats' phenotype, antioxidants and inflammatory profiles, 64 wistar rats were divided into dietary groups of 8 male and 8 female animals each. The animals were fed standard diet as control (chow), chow and carbonated soda, a high protein diet (48.1% energy from protein) and a high protein diet with carbonated soda according to their groups. Body measurements, blood glucose levels, serum insulin levels, lipid peroxidation, antioxidant activity, adipokines and inflammatory markers concentrations were all determined. At the end of the study, body measurements, inflammatory markers and adipokine concentration were increased in animals fed the high protein diet and high protein-soda diet. There was a decrease in antioxidant and lipid peroxidation levels in protein fed male and female animals but those fed protein in combination with soda had increased lipid peroxidation levels. In conclusion, high protein diet in combination with carbonated soda impacts physiology differently from a high protein diet alone, and may stimulate weight gain, oxidative stress and HPD-related inflammation in Wistar rats.

Activation of calcium-sensing receptors in the basolateral nucleus of the amygdala inhibits food intake and induces anxiety-depressive-like emotions via dopamine system

The calcium-sensing receptor (CaSR) is abundantly expressed in gastrointestinal mucosa and participates in the regulation of feeding by affecting hormone secretion. Studies have demonstrated that the CaSR is also expressed in feeding-related brain areas, such as the hypothalamus and limbic system, but the effect of the central CaSR on feeding has not been reported. Therefore, the aim of this study was to explore the effect of the CaSR in the basolateral amygdala (BLA) on feeding, and the potential mechanism was also studied. CaSR agonist R568 was microinjected into the BLA of male Kunming mice to investigate the effects of the CaSR on food intake and anxiety-depression-like behaviours. The enzyme-linked immunosorbent assay (ELISA) and fluorescence immunohistochemistry were used to explore the underlying mechanism. Our results showed that microinjection of R568 into the BLA could inhibit both standard and palatable food intake in mice for 0-2 h, induce anxiety-depression-like behaviours, increase glutamate levels in the BLA, and activate dynorphin and gamma-aminobutyric acid neurons through the N-methyl-D-aspartate receptor and thus reduce the content of dopamine in the arcuate nucleus of the hypothalamus (ARC) and ventral tegmental area (VTA), respectively. Our findings suggest that activation of the CaSR in the BLA inhibited food intake and caused anxiety-depression-like emotions. The reduced dopamine levels in the VTA and ARC via glutamatergic signals are involved in these functions of CaSR.

Associations between sheep meat intake frequency and blood plasma levels of metabolites and lipoproteins in healthy Uzbek adults

INTRODUCTION

Uzbekistan is one of the countries with the highest number of diet-related chronic diseases, which is believed to be associated with high animal fat intake. Sheep meat is high in fats (~ 5% in muscle), including saturated and monounsaturated fatty acids, and it contains nearly twice the higher amounts of n-3 polyunsaturated fatty acids and conjugated linoleic acids compared to beef. Nevertheless, sheep meat is considered health promoting by the locals in Uzbekistan and it accounts for around 1/3 of red meat intake in the country.

OBJECTIVES

The aim of this study was to apply a metabolomics approach to investigate if sheep meat intake frequency (SMIF) is associated with alterations in fasting blood plasma metabolites and lipoproteins in healthy Uzbek adults.

METHODS

The study included 263 subjects, 149 females and 114 males. For each subject a food intake questionnaire, including SMIF, was recorded and fasting blood plasma samples were collected for metabolomics. Blood plasma metabolites and lipoprotein concentrations were determined using ¹H NMR spectroscopy.

RESULTS AND CONCLUSION

The results showed that SMIF was confounded by nationality, sex, body mass index (BMI), age, intake frequency of total meat and fish in ascending order (p < 0.01). Multivariate and univariate data analyses showed differences in the levels of plasma metabolites and lipoproteins with respect to SMIF. The effect of SMIF after statistical adjustment by nationality, sex, BMI, age, intake frequency of total meat and fish decreased but remained significant. Pyruvic acid, phenylalanine, ornithine, and acetic acid remained significantly lower in the high SMIF group, whereas choline, asparagine, and dimethylglycine showed an increasing trend. Levels of cholesterol, apolipoprotein A1, as well as low- and high-density lipoprotein subfractions all displayed a decreasing trend with increased SMIF although the difference were not significant after FDR correction.

Gut microbiome and cancer implications: Potential opportunities for fermented foods

There is a critical opportunity to improve response to immunotherapies and overall cancer survivorship via dietary interventions targeted to modify the gut microbiome, and in turn, potentially enhance anti-cancer immunity. A promising dietary intervention is fermented foods, which may alter gut microbiome composition and, in turn, improve immunity. In this article, we summarize the state of the literature pertaining to the gut microbiome and response to immunotherapy and other cancer treatments, potential clinical implications of utilizing a fermented foods dietary approach to improve cancer treatment outcomes, and existing gaps in the literature regarding the implementation of fermented food interventions among individuals with cancer or with a history of cancer. This review synthesizes a compelling rationale across different disciplines to lay a roadmap for future fermented food dietary intervention research aimed at modulating the gut microbiome to reduce cancer burden.

Dietary cysteine drives body fat loss via FMRFamide signaling in Drosophila and mouse

Obesity imposes a global health threat and calls for safe and effective therapeutic options. Here, we found that protein-rich diet significantly reduced body fat storage in fruit flies, which was largely attributed to dietary cysteine intake. Mechanistically, dietary cysteine increased the production of a neuropeptide FMRFamide (FMRFa). Enhanced FMRFa activity simultaneously promoted energy expenditure and suppressed food intake through its cognate receptor (FMRFaR), both contributing to the fat loss effect. In the fat body, FMRFa signaling promoted lipolysis by increasing PKA and lipase activity. In sweet-sensing gustatory neurons, FMRFa signaling suppressed appetitive perception and hence food intake. We also demonstrated that dietary cysteine worked in a similar way in mice via neuropeptide FF (NPFF) signaling, a mammalian RFamide peptide. In addition, dietary cysteine or FMRFa/NPFF administration provided protective effect against metabolic stress in flies and mice without behavioral abnormalities. Therefore, our study reveals a novel target for the development of safe and effective therapies against obesity and related metabolic diseases.

Global Scientific Trends on Healthy Eating from 2002 to 2021: A Bibliometric and Visualized Analysis

Diet has been recognized as a vital risk factor for non-communicable diseases (NCDs), climate changes, and increasing population, which has been reflected by a rapidly growing body of the literature related to healthy eating. To reveal a panorama of the topics related to healthy eating, this study aimed to characterize and visualize the knowledge structure, hotspots, and trends in this field over the past two decades through bibliometric analyses. Publications related to healthy eating between 1 January 2002 and 31 December 2021 were retrieved and extracted from the Web of Science database. The characteristics of articles including publication years, journals, authors, institutions, countries/regions, references, and keywords were assessed. The analyses on co-authorship, co-occurrence, and co-citation were performed and network visualization maps were constructed by VOSviewer. Major subdomains identified by bibliometrics were further discussed and analyzed. A total of 12,442 articles on healthy eating were identified. Over the past two decades, the annual global publications increased from 71 to 1764, showing a nearly 25-fold growth. The journal Nutrients published the most articles and The American Journal of Clinical Nutrition possessed the highest citations. The United States, Harvard University, and Hu, Frank B. were identified as the most productive and influential country, institution, and author, respectively. The co-occurrence cluster analysis of the top 100 keywords formed four clusters: (1) the food insecurity environment for youths highlighting the necessity and significance of implementing healthy eating in early life; (2) sustainable advantages of the Mediterranean diet; (3) the importance of an overall healthy lifestyle optimization leveraged by eHealth; (4) the challenges during the course of healthy eating against obesity, which are prominent in reflecting the knowledge structure, hotspots, and trends. Moreover, COVID-19, orthorexia nervosa, sustainability, microbiota, food insecurity, and e-health are identified keywords that represented the latest high-frequency keywords and indicated the emerging frontiers of healthy eating. This study indicates that the number of publications on healthy eating will increase in the future and that healthy dietary patterns and clinical applications of healthy eating will be the next hotspots in this research field.

Effects of Poria cocos extract and protein powder mixture on glucolipid metabolism and rhythm changes in obese mice

Herein, we explored the effects of Poria cocos extract, protein powder mixture, and their combined intervention on weight loss in high-fat diet (HFD)-induced obese mice. Male C57BL/6J mice were selected and fed a HFD for 8 weeks; obese mice that were successfully modeled were divided into modeling and five intervention groups, and given the corresponding treatment for 10 weeks. Body weight, fat, and muscle tissue, blood glucose, lipids, inflammatory factors, and other glucose and lipid metabolism-related indicators were measured to evaluate the effect of P. cocos and protein powder intervention on weight loss in obese mice. The body weight of the intervention group was reduced compared with the HFD group. Fat content of mice in F3PM group decreased significantly (p < .05). Levels of blood glucose, lipids, adiponectin, leptin, and inflammatory factors, including interleukin-1 β and tumor necrosis factor- α showed improvement. Lipoprotein lipase (lower about 2.97 pg/ml, vs. HFD mice 10.65 mmoL/ml) and sterol regulatory element-binding transcription factor (lower about 1413.63 pg/ml, vs. HFD mice 3915.33 pg/ml) levels in liver tissue were decreased. The respiratory exchange rate (RER) of mice in the HFD and subject intervention groups had no circadian rhythm and was maintained at approximately 0.80. The protein powder mixture (PM) group had the lowest RER (p < .05), the P. cocos extract (FL) and F1PM groups had similar RER to the HFD group (p < .05), and the F2PM group had a higher RER than the HFD group (p < .05). And food intake and energy metabolism returned to circadian rhythm, with an increase in the dose of P. cocos extract, the feeding rhythms of F1PM, F2PM, and F3PM were closer to that of the normal diet (ND) group. Feeding intervention with P. cocos and protein powder improved fat distribution, glucolipid metabolism, and energy metabolism, with the combination of F3PM showing more diverse benefits.

Effect of the Implementation of a Structured Diet Management Plan on the Severity of Obstructive Sleep Apnea: A Systematic Review

PURPOSE OF REVIEW

The prevalence of obstructive sleep apnea (OSA) is increasing worldwide, in line with the increase in obesity prevalence. Taken into consideration the low compliance rates to continuous positive airway pressure (CPAP) treatment, and since obesity is a risk factor for OSA, these patients should receive additional counseling for weight loss through a diet plan. The aim of this review is to examine the role of a structured diet management plan on OSA severity, nocturnal oxygen indices, and subjective sleep parameters.

RECENT FINDINGS

Τhis systematic review of the literature resulted in four studies and demonstrated that severity of OSA, assessed by the apnea-hypopnea index, is reduced by a dietary management plan when delivered through an educational program. Moreover, nocturnal oxygenation is improved, as well as subjective sleep parameters, when initiating a diet on top of CPAP use. In summary, the present systematic review reports on the beneficial effects of a structured diet management plan in patients with OSA. Although CPAP remains the gold standard of OSA treatment, a specific dietary plan should be sought when managing patients with OSA. Nevertheless, still the evidence is low, and further research on this field is needed to reduce the burden of OSA.

Clinical Evidence of Low-Carbohydrate Diets against Obesity and Diabetes Mellitus

The popularity of low-carbohydrate diets (LCDs) in the last few decades has motivated several research studies on their role in a variety of metabolic and non-morbid conditions. The available data of the results of these studies are put under the research perspective of the present literature review of clinical studies in search of the effects of LCDs on Obesity and Diabetes Mellitus. The electronic literature search was performed in the databases PubMed, Cochrane, and Embase. The literature search found seven studies that met the review's inclusion and exclusion criteria out of a total of 2637 studies. The included studies involved randomized controlled trials of at least 12 weeks' duration, in subjects with BMI ≥ 25 kg/m², with dietary interventions. The results of the study on the effects of LCDs on obesity showed their effectiveness in reducing Body Mass Index and total body fat mass. In addition, LCDs appear to cause drops in blood pressure, low-density lipoprotein (LDL), and triglycerides, and seem to improve high-density lipoprotein (HDL) values. Regarding the effectiveness of LCDs in Diabetes Mellitus, their effect on reducing insulin resistance and fasting blood glucose and HbA1c values are supported. In conclusion, the results suggest the critical role of LCDs to improve the health of people affected by obesity or diabetes.

Physiologic and epigenetic effects of nutrients on disease pathways

BACKGROUND/OBJECTIVES

Epigenetic regulation by nutrients can influence the development of specific diseases. This study sought to examine the effect of individual nutrients and nutrient families in the context of preventing chronic metabolic diseases via epigenetic regulation. The inhibition of lipid accumulation and inflammation by nutrients including proteins, lipids, vitamins, and minerals were observed, and histone acetylation by histone acetyltransferase (HAT) was measured. Correlative analyses were also performed.

MATERIALS/METHODS

Nutrients were selected according to information from the Korean Ministry of Food and Drug Safety. Selected nutrient functionalities, including the attenuation of fatty acid-induced lipid accumulation and lipopolysaccharide-mediated acute inflammation were evaluated in mouse macrophage Raw264.7 and mouse hepatocyte AML-12 cells. Effects of the selected nutrients on in vitro HAT inhibition were also evaluated.

RESULTS

Nitric oxide (NO) production correlated with HAT activity, which was regulated by the amino acids group, suggesting that amino acids potentially contribute to the attenuation of NO production via the inhibition of HAT activity. Unsaturated fatty acids tended to attenuate inflammation by inhibiting NO production, which may be attributable to the inhibition of in vitro HAT activity. In contrast to water-soluble vitamins, the lipid-soluble vitamins significantly decreased NO production. Water- and lipid-soluble vitamins both exhibited significant inhibitory activities against HAT. In addition, calcium and manganese significantly inhibited lipid accumulation, NO production, and HAT activity.

CONCLUSIONS

Several candidate nutrients and their family members may have roles in the prevention of diseases, including hepatic steatosis and inflammation-related diseases (i.e., nonalcoholic steatohepatitis) via epigenetic regulation. Further studies are warranted to determine which specific amino acids, unsaturated fatty acids and lipid-soluble vitamins or specific minerals influence the development of steatosis and inflammatory-related diseases.

Health-Promoting Potential of Millet: A Review

Being a key source of animal food, millet production has been sharply increasing over the last few years in order to cope with the dietary requirements of the ever-increasing world population. It is a splendid source of essential nutrients such as protein, carbohydrates, fat, minerals, vitamins, and also some other bioactive compounds that eventually help through multiple biological activities, including antioxidant, anti-hyperglycemic, anti-cholesterol, anti-hypertensive, anthropometric effects and regulation of gut microbiota composition. These bioactive compounds, nutrients, and functions of cereal grains can be affected by processing techniques such as decortication, soaking, malting, milling, fermentation, etc. This study discusses the nutritional and functional properties of millet-incorporated foods and their impact on health, based on around 150 articles between 2015 and 2022 from the Web of Science, Google Scholar, Food and Agriculture Organization of the United Nations (FAO), Breeding Bid Survey (BBS), and FoodData Central (USDA) databases. Analyzing literature reviews, it is evident that the incorporation of millet and its constituents into foodstuffs could be useful against undernourishment and several other health diseases. Additionally, this review provides crucial information about the beneficial features of millet, which can serve as a benchmark of guidelines for industry, consumers, researchers, and nutritionists.

L-Theanine Mitigates the Harmful Effects of Excess High-Protein Diet in Rats by Regulating Protein Metabolism

SCOPE

l-Theanine (LTA) is a non-protein amino acid that contributes to the flavor of tea and can regulate protein metabolism of healthy organisms. However, it is unknown whether it regulates protein metabolism in individuals on high-protein diets (HPDs).

METHODS AND RESULTS

Here, Sprague-Dawley rats are fed HPDs with different protein supply ratios and administered a diverse dose of LTA for 40 days. Results show that HPDs with an energy supply ratio from protein >40% impair the liver and kidneys, elevate serum ammonia and urea nitrogen, induce amino acid (AA) catabolism, and promote fatty acid (FA) synthesis via FA-binding protein 5 (Fabp5) and acetyl-CoA carboxylase 1 (ACC1). LTA intervention alleviates HPD-induced hepatic and renal injury and improves serum biochemical indices. It increases hepatic free AA content and inhibits FA synthesis by downregulating Fabp5 and ACC1. It promotes protein synthesis by acting on the mammalian target of rapamycin (mTOR) pathway, thereby alleviating HPD-induced metabolic disorders.

CONCLUSIONS

This study demonstrates that LTA mitigates kidney and liver damage induced by long-term excess HPDs by regulating protein metabolism.

Identifying lifestyle factors associated to co-morbidity of obesity and psychiatric disorders, a pilot study

Obesity and psychiatric disorders are linked through a bidirectional association. Obesity rates have tripled globally in the past decades, and it is predicted that by 2025, one billion people will be affected by obesity, often with a co-morbidity such as depression. While this co-morbidity seems to be a global health issue, lifestyle factors associated to it differ between countries and are often attributed to more than one factor. Prior obesity studies were performed in Western populations; this is the first study that investigates lifestyle factors relating to obesity and mental health of the diverse population in Qatar, a country that has witnessed tremendous lifestyle change in a short time. In this pilot study, we surveyed 379 respondents to assess and compare the lifestyles of Qatar residents to the global population. However due to the high proportion of responses from the United Kingdom (UK) residents, we have made comparisons between Qatar residents and UK residents. We used chi-square analysis, spearman rank correlation and logistic regression to compare the lifestyle factors of individuals suffering from both increased BMI and mental health conditions. The types of food consumed, stress, exercise frequency and duration, alcohol and tobacco consumption, and sleep duration, were explored and results argue that different lifestyle factors can contribute to the same health condition, suggesting different mechanisms involved. We found that both groups reported similar sleep durations (p = 0.800), but that perception of sleep (p = 0.011), consumption of alcohol (p = 0.001), consumption of takeaway food (p = 0.007), and physical activity significantly varied between the groups (p = 0.0001). The study examined the predictors of comorbidity in Qatar as well as UK populations using multivariate logistic regression analysis. The result of the study showed no statistical association between comorbidity and the predictors drinking habit, smoking, physical activity, vegetable consumption, eat outs, and sleep perception for the Qatar population, and for the combined population. This study, however showed a significant association (p = 0.033) between sleep perception and comorbidity for the UK population. We conclude that further analysis is needed to understand the relationship between specific lifestyle factors and multimorbidity in each country.

Activation of Calcium-Sensing Receptor in the Area Postrema Inhibits Food Intake via Glutamatergic and GABAergic Signaling Pathways

SCOPE

A high-protein diet has become a popular way to lose weight. Calcium-sensing receptor (CaSR) is activated by amino acids in addition to calcium ions. CaSR shows dense expression in the area postrema (AP), which participates in feeding regulation. The effect of CaSR in the AP on food intake and the potential mechanism involved is investigated.

METHODS AND RESULTS

Male C57BL/6 mice are used to observe the effect of R568 (agonist of CaSR) on food intake. Enzyme-linked immunosorbent assay, immunofluorescence staining, and chemogenetics are used to explore the neural signaling involved. CaSR activation in the AP inhibited acute feeding; R568 increases the content of glutamate and γ-aminobutyric acid (GABA) in the AP, whereas only glutamatergic neurons mediate the effect of R568. GABA-A receptor and ionic glutamate receptor (N-methyl-D-aspartate receptor [NMDAR]) in the paraventricular nucleus of hypothalamus (PVN) are involved in the effect of R568. Promotion of oxytocin (OT) synthesis in the PVN also participates in the effect of R568, and this mechanism is mediated by NMDAR in the PVN.

CONCLUSION

CaSR activation in the AP suppresses feeding, and AP-PVN glutamatergic and GABAergic signaling pathways are involved.

Dietary protein and the glycemic index handle insulin resistance within a nutritional program for avoiding weight regain after energy-restricted induced weight loss

Background and aim

The role of dietary protein and glycemic index on insulin resistance (based on TyG index) within a nutritional program for weight loss and weight maintenance was examined.

Methods

This study analyzed 744 adults with overweight/obesity within the DIOGenes project. Patients who lost at least 8% of their initial weight (0–8 weeks) after a low-calorie diet (LCD) were randomly assigned to one of five ad libitum diets designed for weight maintenance (8–34 weeks): high/low protein (HP/LP) and high/low glycemic index (HGI/LGI), plus a control. The complete nutritional program (0–34 weeks) included both LCD plus the randomized diets intervention. The TyG index was tested as marker of body mass composition and insulin resistance.

Results

In comparison with the LP/HGI diet, the HP/LGI diet induced a greater BMI loss (p < 0.05). ∆TyG was positively associated with resistance to BMI loss (β = 0.343, p = 0.042) during the weight maintenance stage. In patients who followed the HP/LGI diet, TyG (after LCD) correlated with greater BMI loss in the 8–34 weeks period (r = −0.256; p < 0.05) and during the 0–34 weeks intervention (r = −0.222, p < 0.05) periods. ΔTyG₁ value was associated with ΔBMI₂ (β = 0.932; p = 0.045) concerning the HP/LGI diet.

Conclusions

A HP/LGI diet is beneficial not only for weight maintenance after a LCD, but is also related to IR amelioration as assessed by TyG index changes. Registration Clinical Trials NCT00390637.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00707-y.

The gut microbiome as possible mediator of the beneficial effects of very low calorie ketogenic diet on type 2 diabetes and obesity: a narrative review

Several studies have shown a strong correlation between the different types of diets and gut microbiota composition on glycemia and weight loss. In this direction, low-carbohydrate and ketogenic diets have gained popularity, despite studies published so far leading to controversial results on subjects with diabetes. In this narrative review, firstly, we aimed to analyze the role of very-low-calorie ketogenic diets (VLCKDs) in type 2 diabetes (T2DM) and obesity management. Secondly, in this context, we focused attention on gut microbiota as a function of VLCKD, particularly in T2DM and obesity treatment. Finally, we reported all this evidence to underline the importance of gut microbiota to exalt new nutritional strategies for "tailor-made" management, treatment, and rehabilitation in subjects with T2DM and obesity, even with diabetic complications. In conclusion, this narrative review outlined the beneficial impact of VLCKD on gut microbiota even in subjects with T2DM and obesity, and, despite inner VLCKD short-duration feature allowing no sound-enough provisions for long-term outcomes, witnessed in favor of the short-term safety of VLCKD in those patients.Level of evidence Level V: Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.