Adherence and Dietary Composition during Intermittent vs. Continuous Calorie Restriction: Follow-Up Data from a Randomized Controlled Trial in Adults with Overweight or Obesity

Although intermittent calorie restriction (ICR) has become popular as an alternative weight loss strategy to continuous calorie restriction (CCR), there is insufficient evidence on diet quality during ICR and on its feasibility over longer time periods. Thus, we compared dietary composition and adherence between ICR and CCR in a follow-up analysis of a randomized trial. A total of 98 participants with overweight or obesity [BMI (kg/m2) 25–39.9, 35–65 years, 49% females] were randomly assigned to ICR, operationalized as a “5:2 diet” (energy intake: ~100% on five non-restricted (NR) days, ~25% on two restricted (R) days), or CCR (daily energy intake: ~80%). The trial included a 12-week (wk) intervention phase, and follow-up assessments at wk24, wk50 and wk102. Apart from a higher proportion of energy intake from protein with ICR vs. CCR during the intervention (wk2: p < 0.001; wk12: p = 0.002), there were no significant differences with respect to changes in dietary composition over time between the groups, while overall adherence to the interventions appeared to be good. No significant difference between ICR and CCR regarding weight change at wk102 was observed (p = 0.63). However, self-reported adherence was worse for ICR than CCR, with 71.1% vs. 32.5% of the participants reporting not to or only rarely have followed the regimen to which they were assigned between wk50 and wk102. These results indicate that within a weight management setting, ICR and CCR were equivalent in achieving modest weight loss over two years while affecting dietary composition in a comparable manner.

Rapid Weight Loss Habits before a Competition in Sambo Athletes

Background: Like other combat sports, sambo has competition rules that divide athletes into categories based on gender, age and weight. Athletes in combat sports often resort to rapid weight loss (RWL) methods to be more competitive in lower weight categories and gain an advantage against lighter, smaller and weaker competitors. The aim of this study was to examine the methodology implemented by two different sambo age categories, junior and senior athletes, in order to attain RWL. Methods: The sample consisted of 103 male sambo elite athletes (seniors/juniors: age 28.5 ± 4.3/18.9 ± 0.8; height (m): 1.7 ± 0.1/1.8 ± 0.1; weight (kg): 76.3 ± 17.8/74.4 ± 16.3; BMI (kg/m2): 25.0 ± 3.8/23.7 ± 3.9) who completed a survey on RWL. Results: Athletes reported losing a mean of 5 kg starting approximately 12 days before a competition. The most common methodology reported by senior and junior sambo athletes was gradually increasing dieting, followed by sauna and plastic suit training. Less common methods adopted were laxatives, diuretics, the use of diet pills and vomiting. There were significant group differences for sauna and diet pill ingestion. Coaches and parents are influential people in the lives of athletes concerning the weight loss strategy to be adopted. Conclusions: This study’s results unequivocally confirm the prevalent practice of RWL in both senior and junior sambo athletes. Although athletes prevalently chose “less harmful” methods, there is a need to inform parents and coaches of the risks and benefits of RWL.

CARDIAC SYMPATHETIC MODULATION INCREASE AFTER WEIGHT LOSS IN COMBAT SPORTS ATHLETES

ABSTRACT Introduction: Although the rapid weight loss process is undertaken by combat sports athletes very often, the impact of this practice on cardiovascular health is not fully understood. Objective: To verify the effects of the rapid weight loss process undertaken by combat sports athletes on hemodynamic parameters, cardiovascular autonomic modulation and mood state. Methods: Eight male fighters (21.62±1.49 years, 71.25±3.54 kg, 1.74±0.03 cm) were assessed in the city of São Paulo. The subjects had 5.37±0.77 years of practice and were training 5.75±0.45 days per week, for 3.05±0.69 hours per day. The athletes were assessed on 2 occasions: 14 days before and 1 day before official weigh-in. Weight, height and bioimpedance were used for body composition analysis. Mood state was assessed using the Brums Mood Scale. Blood pressure was measured at rest with a digital meter. Cardiovascular autonomic modulation was obtained through an analysis of heart rate variability recorded for 25 minutes at rest. The Student's t-test for dependent samples was used for comparison between time points. Values of p<0.05 were considered significant. Results: No differences in body composition were observed between the time points evaluated. After the weight loss strategy, increases in mood state parameters related to anger, vigor and fatigue categories were observed. Blood pressure did not change between the time points evaluated. However, an increase in heart rate associated with greater sympathetic modulation was observed after the weight loss strategy. There were no differences in autonomic modulation parameters representing parasympathetic activity. Conclusions: The study provided evidence of a higher cardiovascular risk in athletes as a result of this rapid weight loss practice, which is very concerning since combat sports athletes repeat this process several times during their lives. Level of Evidence IV; Study type: Case series.

Microbial enterotypes in personalized nutrition and obesity management

Human gut microbiota has been suggested to play an important role in nutrition and obesity. However, formulating meaningful and clinically relevant dietary advice based on knowledge about gut microbiota remains a key challenge. A number of recent studies have found evidence that stratification of individuals according to 2 microbial enterotypes (dominance of either Prevotella or Bacteroides) may be useful in predicting responses to diets and drugs. Here, we review enterotypes in a nutritional context and discuss how enterotype stratification may be used in personalized nutrition in obesity management. Enterotypes are characterized by distinct digestive functions with preference for specific dietary substrate, resulting in short-chain fatty acids that may influence energy balance in the host. Consequently, the enterotype potentially affects the individual's ability to lose weight when following a specific diet. In short, a high-fiber diet seems to optimize weight loss among Prevotella-enterotype subjects but not among Bacteroides-enterotype subjects. In contrast, increasing bifidobacteria in the gut among Bacteroides-enterotype subjects improves metabolic parameters, suggesting that this approach can be used as an alternative weight loss strategy. Thus, enterotypes, as a pretreatment gut microbiota biomarker, have the potential to become an important tool in personalized nutrition and obesity management, although further interventions assessing their applicability are warranted.

The Role of Choice in Weight Loss Strategies: A Systematic Review and Meta-Analysis

Effective strategies to achieve weight loss and long-term weight loss maintenance have proved to be elusive. This systematic review and meta-analysis aims to explore whether the choice of weight loss strategy is associated with greater weight loss. An electronic search was conducted using the MEDLINE (Medical Literature Analysis and Retrieval System Online, or MEDLARS Online), EMBASE (Excerpta Medica database), CINAHL (Cumulative Index to Nursing and Allied Health Literature), and PsycINFO (Database of Abstracts of Literature in the Field of Psychology, produced by the American Psychological Association and distributed on the association’s APA PsycNET) databases for clinical trials and randomized controlled trials, investigating the role of choice in weight loss strategies. A total of nine studies were identified as meeting the pre-specified criteria. All of the studies included a ‘Choice’ or preference arm and a ‘No Choice’ arm or group who did not receive their preference as a control. A total of 1804 subjects were enrolled in these studies, with weight loss observed in both experimental and control groups of all studies, irrespective of dietary intervention, study duration, or follow-up length. Twelve interventions in nine trials were used for the meta-analysis, with results indicating a greater weight loss in the control groups, 1.09 ± 0.28 (overall mean difference in weight loss between groups ± standard error; p = 0). There was no significant effect of duration or attrition. In this meta-analysis, the choice of weight loss strategy did not confer a weight loss benefit.

Effects of the Dietary Protein and Carbohydrate Ratio on Gut Microbiomes in Dogs of Different Body Conditions

ABSTRACT Obesity has become a health epidemic in both humans and pets. A dysbiotic gut microbiota has been associated with obesity and other metabolic disorders. High-protein, low-carbohydrate (HPLC) diets have been recommended for body weight loss, but little is known about their effects on the canine gut microbiome. Sixty-three obese and lean Labrador retrievers and Beagles (mean age, 5.72 years) were fed a common baseline diet for 4 weeks in phase 1, followed by 4 weeks of a treatment diet, specifically, the HPLC diet (49.4% protein, 10.9% carbohydrate) or a low-protein, high-carbohydrate (LPHC) diet (25.5% protein, 38.8% carbohydrate) in phase 2. 16S rRNA gene profiling revealed that dietary protein and carbohydrate ratios have significant impacts on gut microbial compositions. This effect appeared to be more evident in obese dogs than in lean dogs but was independent of breed. Consumption of either diet increased the bacterial evenness, but not the richness, of the gut compared to that after consumption of the baseline diet. Macronutrient composition affected taxon abundances, mainly within the predominant phyla, Firmicutes and Bacteroidetes. The LPHC diet appeared to favor the growth of Bacteroides uniformis and Clostridium butyricum, while the HPLC diet increased the abundances of Clostridium hiranonis, Clostridium perfringens, and Ruminococcus gnavus and enriched microbial gene networks associated with weight maintenance. In addition, we observed a decrease in the Bacteroidetes to Firmicutes ratio and an increase in the Bacteroides to Prevotella ratio in the HPLC diet-fed dogs compared to these ratios in dogs fed other diets. Finally, analysis of the effect of diet on the predicted microbial gene network was performed using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). IMPORTANCE More than 50% of dogs are either overweight or obese in the United States. A dysbiotic gut microbiota is associated with obesity and other metabolic problems in humans. HPLC diets have been promoted as an effective weight loss strategy for many years, and potential effects were reported for both humans and dogs. In this study, we explored the influence of the protein and carbohydrate ratio on the gut microbiome in dogs with different body conditions. We demonstrated significant dietary effects on the gut microbiome, with greater changes in obese dogs than in lean dogs. The HPLC diet-fed dogs showed greater abundances of Firmicutes but fewer numbers of Bacteroidetes than other dogs. This knowledge will enable us to use prebiotics, probiotics, and other nutritional interventions to modulate the gut microbiota and to provide an alternative therapy for canine obesity. IMPORTANCE More than 50% of dogs are either overweight or obese in the United States. A dysbiotic gut microbiota is associated with obesity and other metabolic problems in humans. HPLC diets have been promoted as an effective weight loss strategy for many years, and potential effects were reported for both humans and dogs. In this study, we explored the influence of the protein and carbohydrate ratio on the gut microbiome in dogs with different body conditions. We demonstrated significant dietary effects on the gut microbiome, with greater changes in obese dogs than in lean dogs. The HPLC diet-fed dogs showed greater abundances of Firmicutes but fewer numbers of Bacteroidetes than other dogs. This knowledge will enable us to use prebiotics, probiotics, and other nutritional interventions to modulate the gut microbiota and to provide an alternative therapy for canine obesity.

Experiences of Daily Weighing Among Successful Weight Loss Individuals During a 12-Month Weight Loss Study

The purpose of the study was to describe participants’ experience of daily weighing and to explore factors influencing adherence to daily weighing among individuals who were successful in losing weight during a behavioral weight loss intervention. Participants completed a 12-month weight loss intervention study that included daily self-weighing using a Wi-Fi scale. Individuals were eligible to participate regardless of their frequency of self-weighing. The sample ( N = 30) was predominantly female (83.3%) and White (83.3%) with a mean age of 52.9 ± 8.0 years and mean body mass index of 33.8 ± 4.7 kg/m2. Five main themes emerged: reasons for daily weighing (e.g., feel motivated, being in control), reasons for not weighing daily (e.g., interruption of routine), factors that facilitated weighing, recommendations for others about daily weighing, and suggestions for future weight loss programs. Our results identified several positive aspects to daily self-weighing, which can be used to promote adherence to this important weight loss strategy.