Appetite and gut peptide responses to exercise and calorie restriction. The effect of modest energy deficits

Impact of physical activity on caloric and macronutrient intake in children and adolescents: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Physical activity is widely promoted to maintain and improve health across all ages. Investigating how physical activity affects subsequent food intake provides insight into the factors that contribute to maintaining energy balance and effective weight management.

OBJECTIVE

This systematic review and meta-analysis summarizes the evidence on the effect of acute physical activity on subsequent food intake in children and adolescents.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) were applied. Randomized controlled trials (RCTs) objectively measuring post-exercise energy intake in children and adolescents aged 5 to 18 years were included. Studies with self-reported food intake were excluded. The databases PubMed, Web of Science and Cochrane Library were searched for RCTs, and the data were summarized at a qualitative and quantitative level. Version 2 of the Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. Changes in energy intake were examined with random effects meta-analysis. (PROSPERO: CRD42022324259).

RESULTS

Out of 9582 studies, 22 RCTs with cross-over design remained eligible for meta-analysis. The primary outcome was post-intervention energy intake up to the next 24 h. Heterogeneity of studies was moderate, with an I2 of 57%. The median (interquartile range, IQR) energy expended while exercising was 240 (158) kcal. Meta-analysis of 41 study arms (exercise n = 780 and control n = 478) showed no differences in total energy intake between the exercise and control group with a mean difference MD = 23.31 [-27.54, 74.15] kcal. No subgroup differences were found. Macronutrient intake and appetite sensations where not substantially affected.

CONCLUSION

Engaging in exercise is a suitable means of raising activity-induced energy expenditure, without causing any noticeable changes in food intake or hunger within a single day.

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women

PURPOSE

This study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women.

METHODS

Fourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m^-2) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump.

RESULTS

Significant reductions in FM were observed in PER and SER (Δ = - 1.7 ± 0.4 kg; P =  < 0.001; ES = - 0.39 and Δ = - 1.2 ± 0.6 kg; P = 0.002; ES = - 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no significant differences for this variable were found either in PER (Δ = - 0.3 ± 0.1; P = 0.071; ES = - 0.06) or in SER (Δ = - 0.2 ± 0.1; P = 0.578; ES = - 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables.

CONCLUSION

A PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.

Intermittent fasting and protein pacing are superior to caloric restriction for weight and visceral fat loss

OBJECTIVE

This study compared intermittent fasting and protein pacing (IF-P) versus a heart-healthy caloric restriction (CR) diet, matched for energy intake and physical activity energy expenditure, on body weight, total and visceral fat mass, and cardiometabolic health outcomes in adults with obesity.

METHODS

IF-P (n = 21) and CR (n = 20) were assessed pre- (week 0), mid- (week 5), and post- (week 9) intervention.

RESULTS

Both groups reduced (p < 0.05) weight, total and visceral fat mass, blood pressure and lipids, and desire to eat food and increased proportion of fat-free mass. IF-P resulted in greater (p < 0.05) reductions in weight (-9% vs. -5%), total (-16% vs. -9%) and visceral (-33% vs. -14%) fat mass, and desire to eat (-17% vs. 1%) and increased fat-free mass percent (6% vs. 3%) compared with CR. These improvements were despite similar weekly total energy intake (IF-P, 9470 ± 550 vs. CR, 9095 ± 608 kcal/wk; p = 0.90) and physical activity energy expenditure (IF-P, 300 ± 150 vs. CR, 350 ± 200 kcal/d; p = 0.79).

CONCLUSIONS

IF-P and CR optimize weight loss, body composition, cardiometabolic health, and hunger management, with IF-P providing greater benefits.

Does butyrylcholinesterase mediate exercise-induced and meal-induced suppression in acylated ghrelin?

Ample evidence supports the notion that an acute bout of aerobic exercise and meal consumption reduces acylated ghrelin concentration. However, the mechanisms by which this exercise- and meal-induced suppression of acylated ghrelin occurs in humans is unknown. This study aimed to examine the concentration of butyrylcholinesterase (BChE), an enzyme responsible for hydrolysing ghrelin and other appetite-related hormones in response to a single bout of running and a standardised meal in young, healthy men. Thirty-three men (aged 23 ± 2 years, mean ± standard deviation) underwent two (exercise and meal conditions) 2-h laboratory-based experiments. In the exercise condition, all participants ran for 30 min at 70% of the maximum oxygen uptake (0930-1000) and rested until 1130. In the meal condition, participants reported to the laboratory at 0930 and rested until 1000. Subsequently, they consumed a standardised meal (1000-1015) and rested until 1130. Blood samples were collected at baseline (0930), 1000, 1030, 1100 and 1130. BChE concentration was not altered in both the exercise and meal conditions (p > 0.05). However, acylated ghrelin was suppressed after exercise (p < 0.05) and meal consumption (p < 0.05). There was no association between the change in BChE concentration and the change in acylated ghrelin before and after exercise (p = 0.571). Although des-acylated ghrelin concentration did not change during exercise (p > 0.05), it decreased after meal consumption (p < 0.05). These findings suggest that BChE may not be involved in the suppression of acylated ghrelin after exercise and meal consumption.

Appetitive and Metabolic Responses to an Exercise versus Dietary Intervention in Adults with Obesity

Introduction/Purpose

Dietary restriction (DIET) and aerobic exercise (AEX) interventions may impact energy balance differently. Our aim was to describe the effects of weight loss interventions via DIET or AEX on measures of energy balance.

Methods

Adults with overweight or obesity were randomized to 12 weeks of DIET or AEX with similar calorie deficit goals. A study day was conducted before and after the intervention to assess subjective and hormonal (ghrelin, peptide-YY, glucagon-like peptide-1) appetite responses to a control meal, ad libitum energy intake (EI) at a single meal, and over three days of free-living conditions and eating behavior traits. Resting metabolic rate (RMR) was measured with indirect calorimetry and adjusted for body composition measured by dual X-ray absorptiometry. Non-exercise activity was measured using accelerometers.

Results

Forty-four individuals were included (age: 37 ± 9 years, body mass index: 30.6 ± 3.1 kg/m2). Both interventions resulted in weight and fat mass loss. The DIET group lost fat-free mass, although differences between groups were not significant (DIET: -1.2 ± 1.7 kg, p<0.001; AEX: 0.4 ± 1.5 kg, p=0.186; p=0.095 interaction). There were no differences in RMR after body composition adjustment. Both interventions were associated with an increase in dietary restraint (DIET: 4.9 ± 1.2, AEX: 2.8 ± 0.7; p<0.001 in both groups). Hunger decreased with DIET (-1.4 ± 0.5, p=0.003), and disinhibition decreased with AEX (-1.5 ± 0.5, p<0.001), although these changes were not different between groups (i.e., no group × time interaction). No other differences in appetite, EI, or non-exercise physical activity were observed within or between groups.

Conclusions

AEX did not result in compensatory alterations in appetite, ad libitum EI, or physical activity, despite assumed increased energy expenditure. Modest evidence also suggested that disinhibition and hunger may be differentially impacted by weight loss modality.

Intermittent fasting two days versus one day per week, matched for total energy intake and expenditure, increases weight loss in overweight/obese men and women

Background

Intermittent fasting (IF), consisting of either a one-day (IF1) or two consecutive days (IF2) per week, is commonly used for optimal body weight loss. Our laboratory has previously shown an IF1 diet combined with 6d/week of protein pacing (P; 4–5 meals/day evenly spaced, ~ 30% protein/day) significantly enhances weight loss, body composition, and cardiometabolic health in obese men and women. Whether an IF1-P or IF2-P, matched for weekly energy intake (EI) and expenditure (EE), is superior for weight loss, body composition, and cardiometabolic health is unknown.

Methods

This randomized control study directly compared an IF1-P (n = 10) versus an IF2-P (n = 10) diet on weight loss and body composition, cardiovascular (blood pressure and lipids), hormone, and hunger responses in 20 overweight men and women during a 4-week weight loss period. Participants received weekly dietary counseling and monitoring of compliance from a registered dietitian. All outcome variables were assessed pre (week 0) and post (week 5).

Results

Both groups significantly reduced body weight, waist circumference, percent body fat, fat mass, hunger, blood pressure, lipids, glucose, and increased percent fat-free mass (p < 0.05). However, IF2-P resulted in significantly greater reductions in body weight (-29%) and waist circumference (-38%) compared to IF1-P (p < 0.05), and showed a strong tendency for greater reductions in fat mass, glucose, and hunger levels (p < 0.10) despite similar weekly total EI (IF1-P, 9058 ± 692 vs. IF2-P, 8389 ± 438 kcals/week; p = 0.90), EE (~ 300 kcals/day; p = 0.79), and hormone responses (p > 0.10).

Conclusions

These findings support short-term IF1-P and IF2-P to optimize weight loss and improve body composition, cardiometabolic health, and hunger management, with IF2-P providing enhanced benefits in overweight women and men.

Trial registration

This trial was registered March 03, 2020 at www.clinicaltrials.gov as NCT04327141.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-022-00790-0.

The Comparison of the Effects between Continuous and Intermittent Energy Restriction in Short-Term Bodyweight Loss for Sedentary Population: A Randomized, Double-Blind, Controlled Trial

Objective: To compare the effects of continuous energy restriction (CER) and intermittent energy restriction (IER) in bodyweight loss plan in sedentary individuals with normal bodyweight and explore the influence factors of effect and individual retention. Methods: 26 participants were recruited in this randomized controlled and double-blinded trial and allocated to CER and IER groups. Bodyweight (BW), body mass index (BMI), and resting metabolic rate (RMR) would be collected before and after a 4-week (28 days) plan which included energy restriction (CER or IER) and moderate-intensity exercise. Daily intake of three major nutrients (protein, carbohydrate, fat) and calories were recorded. Results: A significant decrease in BW and BMI were reported within each group. No statistically significant difference in the change of RMR in CERG. No statistically significant difference was reported in the effect between groups, neither as well the intake of total calories, three major nutrients, and individual plan retention. The influence factors of IER and CER are different. Conclusion: Both CER and IER are effective and safe energy restriction strategies in the short term. Daily energy intake and physical exercise are important to both IER and CER.

Metabolic and Molecular Subacute Effects of a Single Moderate-Intensity Exercise Bout, Performed in the Fasted State, in Obese Male Rats

Introduction and objectives: Obesity represents a major global public health problem. Its etiology is multifactorial and includes poor dietary habits, such as hypercaloric and hyperlipidic diets (HFDs), physical inactivity, and genetic factors. Regular exercise is, per se, a tool for the treatment and prevention of obesity, and recent studies suggest that the beneficial effects of exercise can be potentiated by the fasting state, thus potentially promoting additional effects. Despite the significant number of studies showing results that corroborate such hypothesis, very few have evaluated the effects of fasted-state exercise in overweight/obese populations. Therefore, the aim of this study was to evaluate the subacute effects (12 h after conclusion) of a single moderate-intensity exercise bout, performed in either a fed or an 8 h fasted state, on serum profile, substrate-content and heat shock pathway–related muscle protein immunocontent in obese male rats. Methods: Male Wistar rats received a modified high-fat diet for 12 weeks to induce obesity and insulin resistance. The animals were allocated to four groups: fed rest (FER), fed exercise (FEE), fasted rest (FAR) and fasted exercise (FAE). The exercise protocol was a 30 min session on a treadmill, with an intensity of 60% of VO₂max. The duration of the fasting period was 8 h prior to the exercise session. After a 12 h recovery, the animals were killed and metabolic parameters of blood, liver, heart, gastrocnemius and soleus muscles were evaluated, as well as SIRT1 and HSP70 immunocontent in the muscles. Results: HFD induced obesity and insulin resistance. Soleus glycogen concentration decreased in the fasted groups and hepatic glycogen decreased in the fed exercise group. The combination of exercise and fasting promoted a decreased concentration of serum total cholesterol and triglycerides. In the heart, combination fasting plus exercise was able to decrease triglycerides to control levels. In the soleus muscle, both fasting and fasting plus exercise were able to decrease triglyceride concentrations. In addition, heat shock protein 70 and sirtuin 1 immunocontent increased after exercise in the gastrocnemius and soleus muscles. Conclusions: An acute bout of moderate intensity aerobic exercise, when realized in fasting, may induce, in obese rats with metabolic dysfunctions, beneficial adaptations to their health, such as better biochemical and molecular adaptations that last for at least 12 h. Considering the fact that overweight/obese populations present an increased risk of cardiovascular events/diseases, significant reductions in such plasma markers of lipid metabolism are an important achievement for these populations.

Gastrointestinal pathophysiology during endurance exercise: endocrine, microbiome, and nutritional influences

Gastrointestinal symptoms are abundant among athletes engaging in endurance exercise, particularly when exercising in increased environmental temperatures, at higher intensities, or over extremely long distances. It is currently thought that prolonged ischemia, mechanical damage to the epithelial lining, and loss of epithelial barrier integrity are likely contributors of gastrointestinal (GI) distress during bouts of endurance exercise, but due to the many potential causes and sporadic nature of symptoms this phenomenon has proven difficult to study. In this review, we cover known factors that contribute to GI distress symptoms in athletes during exercise, while further attempting to identify novel avenues of future research to help elucidate mechanisms leading to symptomology. We explore the link between the intestinal microbiome, the integrity of the gut epithelia, and add detail on gut hormone and peptide secretion that could potentially contribute to GI distress symptoms in athletes. The influence of nutrition and dietary supplementation strategies are also detailed, where much research has opened up new ideas and potential mechanisms for understanding gut pathophysiology during exercise. The etiology of gastrointestinal symptoms during endurance exercise is multi-factorial with neuroendocrine, microbial, and nutritional factors likely contributing to specific, individualized symptoms. Recent work in previously unexplored areas of both microbiome and gut peptide secretion are pertinent areas for future work, and the numerous supplementation strategies explored to date have provided insight into physiological mechanisms that may be targetable to reduce the incidence and severity of gastrointestinal symptoms in athletes.

Diet-induced prediabetes: effects of exercise treatment on risk factors for cardiovascular complications

BACKGROUND

An animal model of prediabetes that has been developed in our laboratory using a high fat high carbohydrate diet and lack of physical activity displays risk factors for cardiovascular complications. The effect of exercise against these risk factors in this animal model remains unknown. Therefore, we evaluated the effect of intermittent and regular exercise treatment on the risk factors for cardiovascular complications in this animal model of prediabetes.

METHODS

Following prediabetes induction, animals were randomly assigned to the following groups (n = 6): non-diabetic, prediabetic, intermittently exercising prediabetic and regularly exercising prediabetic. Exercise exposure was 7 weeks long. Body weight changes, caloric intake, blood glucose, total cholesterol, and triglyceride concentration was measured after 20 and 29 weeks while blood pressure was only measured after 29 weeks. Plasma endothelial nitric oxide synthase, malonaldehyde, glutathione peroxidase, tumour necrosis factor-alpha and C-reactive protein concentration from the heart were measured 2 weeks post-exercise termination (week 30).

RESULTS

We found increased body weight, caloric intake and mean arterial pressure in the prediabetic group by comparison to the non-prediabetic group. The same trend was observed in blood glucose and triglyceride concentrations. However, all of these parameters were reduced in the intermittently exercising prediabetic and regularly exercising prediabetic groups. This reduction was further accompanied by a decrease in the endothelial nitric oxide synthase, tumour necrosis factor-alpha and C-reactive protein concentration with improved oxidative stress biomarkers.

CONCLUSIONS

The progression of pre-diabetes to diabetes is slowed or possibly stopped by exercise (regular or intermittent). Additionally, biomarker profiles indicative of cardiovascular disease in pre-diabetics are improved by exercise.

Energy Balance Dynamics: Exercise, Appetite, Diet, and Weight Control

Individuals seeking to achieve weight loss are encouraged to achieve a negative energy balance, essentially eat less and move more. The complex relationship between energy expenditure and intake is often overlooked, leaving individuals and practitioners underwhelmed by the results of weight loss efforts. Independently, physical activity and diet interventions can yield modest weight loss and when combined have synergistic effects that promote sustained weight loss. Although physical activity benefits appetite suppression, reduces food rewards, and can be considered a gateway to healthy eating, high levels of daily activity are needed to induce weight loss. Diet is an important component to achieving weight loss, and high-protein diets have the potential for supporting weight loss as well. This column will be focused on the benefits of physical activity in reducing body weight, more specifically, the interdependent relationship between dietary intake and physical activity in achieving weight reduction.

Effect of Fasting-Mimicking Diet or Continuous Energy Restriction on Weight Loss, Body Composition, and Appetite-Regulating Hormones Among Metabolically Healthy Women with Obesity: a Randomized Controlled, Parallel Trial

BACKGROUND

Fasting-mimicking diet (FMD) has been recently promoted to achieve similar metabolic changes of fasting. The purpose of our study was to compare the effect of FMD versus continuous energy restriction (CER) on anthropometric measurements, body composition, glucose metabolism, and serum levels of leptin, neuropeptide Y (NPY), and total ghrelin.

METHODS

A randomized controlled trial (RCT) was conducted on 60 women with obesity aged 18-55 years. Subjects received either a 5-day FMD (low in energy, sugars, and proteins, but high in unsaturated fats) or a CER (an average daily energy deficit of 500 kcal) for 2 months. Anthropometric and biochemical factors were measured at baseline and the end of the study. Serum levels of leptin, total ghrelin, and NPY were tested with an ELISA kit. Physical activity and dietary intakes were also recorded.

RESULTS

There was no significant difference in weight loss between the two groups: mean weight change for CER was - 2.29 (standard deviation [SD], 1.95) kg compared to - 1.13 (2.27) kg for FMD (p = 0.06). There was more reduction in the basal metabolic rate (BMR) in the CER group (p = 0.045). Favorable effects on fat mass and muscle mass were only seen in the FMD group. Although insulin resistance was reduced in the FMD group compared to the CER group, results were not significant after adjustment. After controlling for potential confounders, there was a significant increase in serum levels of total ghrelin (p = 0.048) and NPY (p = 0.041) following CER; however, results for circulating leptin were not statistically significant (p = 0.48).

CONCLUSIONS

There was no significant difference in weight loss following FMD and CER. However, FMD was more effective at reducing insulin resistance and regulating appetite-regulating hormones as well as preserving muscle mass and BMR.

TRIAL REGISTRATION

This trial was registered at the Iranian Clinical Trial Registry ( https://www.irct.ir/trial/40881 ) with the IRCT identification number IRCT20190717044244N1.

Short-term interval exercise suppresses acylated ghrelin and hunger during caloric restriction in women with obesity

Caloric restriction is suggested to increase hunger, in part, through complex interactions of hormones and behavior that contribute to challenges in long-term weight loss. Although intense exercise may attenuate appetite, no data exist testing the effects of interval exercise (INT) during a low-calorie diet (LCD) on appetite regulation. We hypothesized that LCD+INT would favorably influence satiety when compared with an energy-deficit matched LCD in women with obesity. Twenty-six women with obesity (47.3±2.4 yrs; 37.3 ± 1.2 kg/m2) were randomized to either LCD (n = 13; mixed meals of ~1200 kcal/d) or LCD+INT (n = 13; 60 min/d of supervised interval exercise at 90% HRpeak for 3 min and 50% HRpeak for 3 min) for 2 weeks. An additional 350kcal (shake) was provided to LCD+INT individuals post-exercise to equate energy availability between groups. Total PYY, acylated ghrelin and des-ghrelin were measured at 0, 30 and 60 min of a 75g OGTT before and after the intervention. Visual analog scales were also administered at 0 and 120 min of the OGTT to assess appetite perception. Food logs were recorded prior to and during the intervention to ensure caloric intake compliance. Compared with pre-intervention conditions, both interventions decreased food intake (P = 0.001) and body fat (P < 0.01). There was no effect on fasting PYY, but both LCD and LCD+INT increased post-prandial PYY iAUC (P < 0.001) relative to pre-intervention. LCD+INT maintained fasting acylated ghrelin (P = 0.06) and suppressed post-prandial acylated ghrelin iAUC (P = 0.04) compared to LCD. Neither intervention impacted circulating des- ghrelin before or following the OGTT. Interestingly, LCD+INT attenuated fasting hunger and maintained fullness compared with LCD (P = 0.05 and P = 0.06, respectively). Taken together, interval exercise favors acylated ghrelin suppression and perception of hunger during a LCD in women with obesity.

Influence of postexercise fasting on hunger and satiety in adults

Research demonstrates that exercise acutely reduces appetite by stimulating the secretion of gut-derived satiety hormones. Currently there is a paucity of research examining the impact of postexercise nutrient intake on appetite regulation. The objective of this study was to examine how postexercise fasting versus feeding impacts the postexercise appetite response. In a randomized crossover intervention, 14 participants (body mass index: 26.9 ± 3.5 kg·m^-2; age: 26.8 ± 6.7 years) received 1 of 2 recovery beverages: (i) water control (FAST) or (ii) sweetened-milk (FED) after completing a 45-min (65%-70% peak oxygen uptake) evening exercise session (∼1900 h). Energy intake was assessed through a fasted ad libitum breakfast meal and 3-day food diaries. Perceived appetite was assessed using visual analogue scales. Appetite-regulating hormones glucagon-like peptide-1 (GLP-1), peptide tyrosine-tyrosine (PYY), and acyl-ghrelin were assessed pre-exercise, 1 h after exercise, and the morning following exercise. FAST increased subjective hunger compared with FED (P < 0.05). PYY and GLP-1 after exercise were decreased and acyl-ghrelin was increased in FAST, with these differences disappearing the day after exercise (P < 0.05). Ad libitum energy intake at breakfast the following morning did not differ between trials. Overall, in the absence of postexercise macronutrient consumption, there was a pronounced increase in objective and subjective appetite after exercise. The orexigenic effects of postexercise fasting, however, were not observed the morning following exercise. Novelty Postexercise fasting leads to reduced GLP-1 and PYY and increased hunger. Reduced GLP-1 and PYY after exercise is blunted by postexercise nutrient intake. Energy intake the day after exercise is not influenced by postexercise fasting.

Daily running exercise may induce incomplete energy intake compensation: a 7-day crossover trial

Understanding daily exercise effects on energy balance is important. This study examined the effects of 7 days of imposed exercise (EX) and no exercise (N-EX) on free-living energy intake (EI) and physical activity energy expenditure (PAEE) in 9 men. Free-living EI was higher in EX compared with N-EX. Total and vigorous PAEE were higher, with PAEE in sedentary activities lower, during EX compared with N-EX. Daily running (for 7 days) induced EI compensation of ∼60% exercise-induced EE. Novelty Daily running for 7 days induced incomplete EI compensation accounting for ∼60% of the exercise-induced EE.

Exploration of associations between the FTO rs9939609 genotype, fasting and postprandial appetite-related hormones and perceived appetite in healthy men and women

BACKGROUND

The fat mass and obesity-associated gene (FTO) rs9939609 A-allele has been associated with obesity risk. Although the exact mechanisms involved remain unknown, the FTO rs9939609 A-allele has been associated with an impaired postprandial suppression of appetite.

OBJECTIVES

To explore the influence of FTO rs9939609 genotype on fasting and postprandial appetite-related hormones and perceived appetite in a heterogeneous sample of men and women.

DESIGN

112 healthy men and women aged 18-50-years-old completed three laboratory visits for the assessment of FTO rs9939609 genotype, body composition, aerobic fitness, resting metabolic rate, visceral adipose tissue, liver fat, fasting leptin, and fasting and postprandial acylated ghrelin, total PYY, insulin, glucose and perceived appetite. Participants wore accelerometers for seven consecutive days for the assessment of physical activity and sedentary behaviour. Multivariable general linear models quantified differences between FTO rs9939609 groups for fasting and postprandial appetite outcomes, with and without the addition of a priori selected physiological and behavioural covariates. Sex-specific univariable Pearson's correlation coefficients were quantified between the appetite-related outcomes and individual characteristics.

RESULTS

95% confidence intervals for mean differences between FTO rs9939609 groups overlapped zero in unadjusted and adjusted general linear models for all fasting (P ≥ 0.28) and postprandial (P ≥ 0.19) appetite-related outcomes. Eta² values for explained variance attributable to FTO rs9939609 were <5% for all outcomes. An exploratory correlation matrix indicated that associations between fasting and postprandial acylated ghrelin, total PYY and general or abdominal adiposity were also small (r = -0.23 to 0.15, P ≥ 0.09). Fasting leptin, glucose and insulin and postprandial insulin concentrations were associated with adiposity outcomes (r = 0.29 to 0.81, P ≤ 0.033).

CONCLUSIONS

Associations between the FTO rs9939609 genotype and fasting or postprandial appetite-related outcomes were weak in healthy men and women.

The influence of exercise training dose on fasting acylated ghrelin concentration in older women

This study investigated if exercise dose affected acylated ghrelin response to exercise training, and how body weight or fat mass changes might affect the responses. Non-obese older women (n = 49) were randomly assigned to 4-month moderate-intensity aerobic exercise of one of two doses (8 or 14 kcal kg-1 body weight weekly). Following exercise training, fasting acylated ghrelin concentrations changed differently between the two groups (p for group × time interaction = 0.050). It decreased in the moderate-dose (Cohen's d = 0.52, p = 0.019), but did not change in the low-dose exercise group. Adjustment for weight or fat changes did not affect these results. Therefore, exercise training dose can have specific effects on acylated ghrelin that are not dependent on weight or fat loss. However, whether the different acylated ghrelin changes are associated with differing degree of subsequent weight maintenance worth further investigation.

Measurement, Determinants, and Implications of Energy Intake in Athletes

Appropriate energy intake is important for the health and performance of athletes. When an athlete's energy intake is not concordant with energy expenditure, short- and long-term performance can be compromised and negative health effects may arise. The energy intake patterns of athletes are subject to numerous effectors, including exercise response, time, and availability of food. To assess different determinants of energy intake in athletes, we reviewed recent literature regarding the response of appetite-regulating hormones to exercise, appetite perceptions following exercise, chronic exercise-induced adaptations regarding appetite, and social factors regarding energy intake. Additionally, we discussed consequences of aberrant energy intake. The purpose of this review is to clarify understanding about energy intake in athletes and provide insights into methods toward maintaining proper energy intake.

A single day of mixed-macronutrient overfeeding does not elicit compensatory appetite or energy intake responses but exaggerates postprandial lipaemia during the next day in healthy young men

Discrete episodes of overconsumption may induce a positive energy balance and impair metabolic control. However, the effects of an ecologically relevant, single day of balanced macronutrient overfeeding are unknown. Twelve healthy men (of age 22 (sd 2) years, BMI 26·1 (sd 4·2) kg/m2) completed two 28 h, single-blind experimental trials. In a counterbalanced repeated measures design, participants either consumed their calculated daily energy requirements (energy balance trial (EB): 10 755 (sd 593) kJ) or were overfed by 50 % (overfeed trial (OF): 16 132 (sd 889) kJ) under laboratory supervision. Participants returned to the laboratory the next day, after an overnight fast, to complete a mixed-meal tolerance test (MTT). Appetite was not different between trials during day 1 (P&gt;0·211) or during the MTT in the fasted or postprandial state (P&gt;0·507). Accordingly, plasma acylated ghrelin, total glucagon-like peptide-1 and total peptide YY concentrations did not differ between trials during the MTT (all P&gt;0·335). Ad libitum energy intake, assessed upon completion of the MTT, did not differ between trials (EB 6081 (sd 2260) kJ; OF 6182 (sd 1960) kJ; P=0·781). Plasma glucose and insulin concentrations were not different between trials (P&gt;0·715). Fasted NEFA concentrations were lower in OF compared with EB (P=0·005), and TAG concentrations increased to a greater extent on OF than on EB during the MTT (P=0·009). The absence of compensatory changes in appetite-related variables after 1 d of mixed macronutrient overfeeding highlights the limited physiological response to defend against excess energy intake. This supports the concept that repeated discrete episodes of overconsumption may promote weight gain, while elevations in postprandial lipaemia may increase CVD risk.

The Unexplored Crossroads of the Female Athlete Triad and Iron Deficiency: A Narrative Review

Despite the severity and prevalence of iron deficiency in exercising women, few published reports have explored how iron deficiency interacts with another prevalent and severe condition in exercising women: the 'female athlete triad.' This review aims to describe how iron deficiency may interact with each component of the female athlete triad, that is, energy status, reproductive function, and bone health. The effects of iron deficiency on energy status are discussed in regards to thyroid function, metabolic fuel availability, eating behaviors, and energy expenditure. The interactions between iron deficiency and reproductive function are explored by discussing the potentially impaired fertility and hyperprolactinemia due to iron deficiency and the alterations in iron metabolism due to menstrual blood loss and estrogen exposure. The interaction of iron deficiency with bone health may occur via dysregulation of the growth hormone/insulin-like growth factor-1 axis, hypoxia, and hypothyroidism. Based on these discussions, several future directions for research are presented.

Structured, aerobic exercise reduces fat mass and is partially compensated through energy intake but not energy expenditure in women

BACKGROUND

Exercise-induced weight loss is often less than expected and highly variable in men and women. Behavioural compensation for the exercise-induced energy deficit could be through energy intake (EI), non-exercise physical activity (NEPA) or sedentary behaviour (SB). We investigated this issue in women.

METHODS

Twenty-four overweight [body mass index (BMI) M = 27.9 kg/m², SD = 2.7] women [age M = 33.1 years, SD = 11.7] completed 12-weeks of supervised exercise (5×500kcal per week) in a non-randomised, pre-post intervention study. Body mass (BM), waist circumference (WC), body composition, resting metabolic rate (RMR), total daily EI, individual meals, appetite sensations and appetite-related peptides were measured at baseline (week 0) and post-intervention (week 12). Free-living physical activity (PA) and SB were measured (SenseWear) at baseline, week 1 and 10 of the exercise intervention, and at post-intervention (week 13).

RESULTS

Following the 12-week exercise intervention BM [p = .04], BMI [p = .035], WC [p < .001] and fat mass (FM) [p = .003] were significantly reduced, and fat-free mass (FFM) significantly increased [p = .003]. Total [p = .028], ad libitum [p = .03] and snack box EI [p = .048] were significantly increased and this was accompanied by an increase in hunger [p = .01] and a decrease in fullness [p = .03] before meals. The peptides did not explain changes in appetite [p > .05]. There was no compensatory reduction in NEPA [p > .05] and no increase in SB, rather there was a decrease in SB during the exercise intervention [p = .03].

CONCLUSIONS

Twelve-weeks of supervised aerobic exercise resulted in a significant reduction in FM and an increase in FFM. Exercise increased hunger and EI which only partially compensated for the increase in energy expenditure. There was no evidence for a compensatory reduction in NEPA or an increase in SB. Dietary intervention, as an adjunct to exercise, may offset the compensatory increase in EI and result in a greater reduction in BM.

TRIAL REGISTRATION

Our trial was retrospectively registered on the International Standard Randomised Controlled Trials Registry (ISRCTN78021668, 27th September 2016) and can be found here: https://doi.org/10.1186/ISRCTN78021668.

Appetite, food intake and gut hormone responses to intense aerobic exercise of different duration

The purpose of the study is to investigate the effect of acute bouts of high-intensity aerobic exercise of differing durations on subjective appetite, food intake and appetite-associated hormones in endurance-trained males. Twelve endurance-trained males (age = 21 ± 2 years; BMI = 21.0 ± 1.6 kg/m²; VO_2max = 61.6 ± 6.0 mL/kg/min) completed four trials, within a maximum 28 day period, in a counterbalanced order: resting (REST); 15 min exercise bout (15-min); 30 min exercise bout (30-min) and 45 min exercise bout (45-min). All exercise was completed on a cycle ergometer at an intensity of ~76% VO_2max Sixty minutes post exercise, participants consumed an ad libitum meal. Measures of subjective appetite and blood samples were obtained throughout the morning, with plasma analyzed for acylated ghrelin, total polypeptide tyrosine-tyrosine (PYY) and total glucagon-like peptide 1 (GLP-1) concentrations. The following results were obtained: Neither subjective appetite nor absolute food intake differed between trials. Relative energy intake (intake - expenditure) was significantly greater after REST (2641 ± 1616 kJ) compared with both 30-min (1039 ± 1520 kJ) and 45-min (260 ± 1731 kJ), and significantly greater after 15-min (2699 ± 1239 kJ) compared with 45-min (condition main effect, P < 0.001). GLP-1 concentration increased immediately post exercise in 30-min and 45-min, respectively (condition × time interaction, P < 0.001). Acylated ghrelin was transiently suppressed in all exercise trials (condition × time interaction, P = 0.011); the greatest, most enduring suppression, was observed in 45-min. PYY concentration was unchanged with exercise. In conclusion, high-intensity aerobic cycling lasting up to 45 min did not suppress subjective appetite or affect absolute food intake, but did reduce relative energy intake, in well-trained endurance athletes. Findings question the role of appetite hormones in regulating subjective appetite in the acute post-exercise period.

Perceived Exertion during Exercise Is Associated with Children's Energy Intake

PURPOSE

To examine the individual-level factors that predict energy intake (EI) after imposed exercise (EX) and sedentary time (SED) in children.

METHODS

Healthy-weight children ages 9-12 yr (n = 20) reported to the laboratory for one baseline and two experimental visits (EX and SED) each separated by 1 wk in a randomized crossover design. Percent body fat, weight (kg), and height (m) were used to calculate fat-mass index (FM index) and fat-free mass index (FFM index; kg·m). On the EX day, children exercised at 70% estimated V˙O2peak for 30 min on a cycle ergometer, whereas cardiovascular responses and RPE were measured. Objective EI (kcal) was measured at identical meals (breakfast, lunch, snack, and dinner) on the EX and SED days.

RESULTS

Total EI was not statistically different between the EX and SED days (t = 1.8, P = 0.09). FFM index was positively associated with EI on the EX day (r = 0.54, P < 0.05). RPE was also positively associated with EI on the EX day (r = 0.82, P < 0.001). Together, FFM index and RPE explained 77% of the variability in EX day EI (F(2,17) = 26.4, P < 0.001). For each unit increase in RPE, children consumed approximately 270 more calories on the EX day. A similar pattern of associations was observed on the SED day.

CONCLUSIONS

FFM index was positively associated with EI on the EX day. Despite experiencing the same 70% relative exercise intensity, increased perceived difficulty predicted greater EI on both the EX and SED day. These findings demonstrate a role for both FFM and RPE in explaining EI variability in children.

Acute effects of exercise on appetite, ad libitum energy intake and appetite-regulatory hormones in lean and overweight/obese men and women

BACKGROUND

Acute exercise does not elicit compensatory changes in appetite parameters in lean individuals; however, less is known about responses in overweight individuals. This study compared the acute effects of moderate-intensity exercise on appetite, energy intake and appetite-regulatory hormones in lean and overweight/obese individuals.

METHODS

Forty-seven healthy lean (n=22, 11 females; mean (s.d.) 37.5 (15.2) years; 22.4 (1.5) kg m^-2) and overweight/obese (n=25, 11 females; 45.0 (12.4) years, 29.2 (2.9) kg m^-2) individuals completed two, 8 h trials (exercise and control). In the exercise trial, participants completed 60 min treadmill exercise (59 (4)% peak oxygen uptake) at 0-1 h and rested thereafter while participants rested throughout the control trial. Appetite ratings and concentrations of acylated ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured at predetermined intervals. Standardised meals were consumed at 1.5 and 4 h and an ad libitum buffet meal was provided at 7 h.

RESULTS

Exercise suppressed appetite (95% confidence interval (CI) -3.1 to -0.5 mm, P=0.01), and elevated delta PYY (95% CI 10 to 17 pg ml^-1, P<0.001) and GLP-1 (95% CI 7 to 10 pmol l^-1, P<0.001) concentrations. Delta acylated ghrelin concentrations (95% CI -5 to 3 pg ml^-1, P=0.76) and ad libitum energy intake (95% CI -391 to 346 kJ, P=0.90) were similar between trials. Subjective and hormonal appetite parameters and ad libitum energy intake were similar between lean and overweight/obese individuals (P⩾0.27). The exercise-induced elevation in delta GLP-1 was greater in overweight/obese individuals (trial-by-group interaction P=0.01), whereas lean individuals exhibited a greater exercise-induced increase in delta PYY (trial-by-group interaction P<0.001).

CONCLUSIONS

Acute moderate-intensity exercise transiently suppressed appetite and increased PYY and GLP-1 in the hours after exercise without stimulating compensatory changes in appetite in lean or overweight/obese individuals. These findings underscore the ability of exercise to induce a short-term energy deficit without any compensatory effects on appetite regardless of weight status.

Potential involvement of lactate and interleukin-6 in the appetite-regulatory hormonal response to an acute exercise bout

This study examines the involvement of two potential mechanisms (lactate and IL-6) that may explain the intensity-dependent effects of acute exercise on appetite-related parameters. Our findings support a clear intensity-dependent paradigm for appetite-regulation following exercise, as highlighted by the change in acylated ghrelin and the suppression of appetite and energy intake after vigorous exercise (continuous and intermittent). Further, our findings extend previous work in animal/cell models by providing evidence for the potential role of lactate and IL-6 in mediating changes in appetite-related parameters following exercise in humans.

High-intensity exercise suppresses appetite partly through changes in peripheral appetite-regulating hormones. Lactate and IL-6 mediate the release of these hormones in animal/cell models and may provide a mechanistic link between exercise intensity and appetite regulation. The current study examined changes in appetite-regulating hormones, lactate, and IL-6 after different intensities of running. Eight males completed four experimental sessions: 1) moderate-intensity continuous training (MICT; 65% V̇o_2max); 2) vigorous-intensity continuous training (VICT; 85% V̇o_2max); 3) sprint interval training (SIT; repeated “all-out” sprints); and 4) Control (CTRL; no exercise). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), total peptide YY (PYY), lactate, IL-6, and appetite perceptions were measured pre-, immediately postexercise, 30 min postexercise, and 90 min postexercise. Energy intake was recorded over 3 days. VICT and SIT suppressed ghrelin (P < 0.001), although SIT elicited a greater (P = 0.016 vs. MICT) and more prolonged (P < 0.001 vs. all sessions) response. GLP-1 increased immediately after MICT (P < 0.001) and 30 min after VICT (P < 0.001) and SIT (P < 0.002), while VICT elicited a greater postexercise increase in PYY vs. MICT (P = 0.027). Postexercise changes in blood lactate and IL-6 correlated with the area under the curve values for ghrelin (r = −0.60, P < 0.001) and GLP-1 (r = 0.42, P = 0.017), respectively. Appetite was suppressed after exercise (P < 0.001), although more so after VICT (P < 0.027) and SIT (P < 0.001) vs. MICT, and energy intake was reduced on the day after VICT (P < 0.017 vs. MICT and CTRL) and SIT (P = 0.049 vs. MICT). These findings support an intensity-dependent paradigm for appetite regulation following exercise and highlight the potential involvement of lactate and IL-6.

NEW & NOTEWORTHY This study examines the involvement of two potential mechanisms (lactate and IL-6) that may explain the intensity-dependent effects of acute exercise on appetite-related parameters. Our findings support a clear intensity-dependent paradigm for appetite regulation following exercise, as highlighted by the change in acylated ghrelin and the suppression of appetite and energy intake after vigorous exercise (continuous and intermittent). Further, our findings extend previous work in animal/cell models by providing evidence for the potential role of lactate and IL-6 in mediating changes in appetite-related parameters following exercise in humans.

Very Low Volume Sprint Interval Exercise Suppresses Subjective Appetite, Lowers Acylated Ghrelin, and Elevates GLP-1 in Overweight Individuals: A Pilot Study

High-intensity exercise has been shown to elicit a transient suppression of appetite and create a more anorexigenic profile of appetite-associated hormones. It is yet to be fully elucidated whether such a response is observed following very low-volume, intermittent exercise at supramaximal intensity in those who are overweight. Eight overweight individuals (BMI 27.7 ± 1.7 kg·m²) completed resting (REST) and exercise (EX) trials in a counterbalanced order. EX consisted of 4 × 30 s “flat-out” cycling on an ergometer (adapted Wingate test). Two hours post-exercise (or REST), participants were presented with an ad libitum meal. Subjective appetite measures and blood samples were obtained throughout. Subjective appetite, measured using VAS, was significantly lower immediately after exercise compared with REST (38.0 ± 28.5 mm vs. 75.1 ± 26.2 mm, p = 0.018, d = 1.09). This difference remained significant 30 min post-exercise. Acylated ghrelin concentration was suppressed in EX compared with REST immediately post-exercise (113.4 ± 43.0 pg·mL⁻¹ vs. 189.2 ± 91.8 pg·mL⁻¹, p = 0.03, d = 1.07) and remained lower until the ad libitum test-meal. Area-under-the-curve for GLP-1 concentration was significantly greater for EX, versus REST. There was no difference in absolute adlibitum intake or relative energy intake. As little as 4 × 30 s of “flat-out” cycling was sufficient to elicit a transient suppression of appetite and an enduring suppression of plasma acylated ghrelin. Nonetheless, food intake 2-h post-exercise was unaffected.

The role of leptin and ghrelin in appetite regulation in the Australian Spinifex hopping mouse, Notomys alexis, during long-term water deprivation

Water deprivation of the Spinifex hopping mouse, Notomys alexis, induced a biphasic pattern of food intake with an initial hypophagia that was followed by an increased, and then sustained food intake. The mice lost approximately 20% of their body mass and there was a loss of white adipose tissue. Stomach ghrelin mRNA was significantly higher at day 2 of water deprivation but then returned to the same levels as water-replete (day 0) mice for the duration of the experiment. Plasma ghrelin was unaffected by water deprivation except at day 10 where it was significantly increased. Plasma leptin levels decreased at day 2 and day 5 of water deprivation, and then increased significantly by the end of the water deprivation period. Water deprivation caused a significant decrease in skeletal muscle leptin mRNA expression at days 2 and 5, but then it returned to day 0 levels by day 29. In the hypothalamus, water deprivation caused a significant up-regulation in both ghrelin and neuropeptide Y mRNA expression, respectively. In contrast, hypothalamic GHSR1a mRNA expression was significantly down-regulated. A significant increase in LepRb mRNA expression was observed at days 17 and 29 of water deprivation. This study demonstrated that the sustained food intake in N. alexis during water deprivation was uncoupled from peripheral appetite-regulating signals, and that the hypothalamus appears to play an important role in regulating food intake; this may contribute to the maintenance of fluid balance in the absence of free water.

Acute effect of exercise intensity and duration on acylated ghrelin and hunger in men

Acute exercise transiently suppresses the orexigenic gut hormone acylated ghrelin, but the extent to which exercise intensity and duration determine this response is not fully understood. The effects of manipulating exercise intensity and duration on acylated ghrelin concentrations and hunger were examined in two experiments. In experiment one, nine healthy males completed three, 4-h conditions (control, moderate-intensity running (MOD) and vigorous-intensity running (VIG)), with an energy expenditure of ~2.5 MJ induced in both MOD (55-min running at 52% peak oxygen uptake (V.O_2peak)) and VIG (36-min running at 75% V.O_2peak). In experiment two, nine healthy males completed three, 9-h conditions (control, 45-min running (EX45) and 90-min running (EX90)). Exercise was performed at 70% V.O_2peak In both experiments, participants consumed standardised meals, and acylated ghrelin concentrations and hunger were quantified at predetermined intervals. In experiment one, delta acylated ghrelin concentrations were lower than control in MOD (ES = 0.44, P = 0.01) and VIG (ES = 0.98, P < 0.001); VIG was lower than MOD (ES = 0.54, P = 0.003). Hunger ratings were similar across the conditions (P = 0.35). In experiment two, delta acylated ghrelin concentrations were lower than control in EX45 (ES = 0.77, P < 0.001) and EX90 (ES = 0.68, P < 0.001); EX45 and EX90 were similar (ES = 0.09, P = 0.55). Hunger ratings were lower than control in EX45 (ES = 0.20, P = 0.01) and EX90 (ES = 0.27, P = 0.001); EX45 and EX90 were similar (ES = 0.07, P = 0.34). Hunger and delta acylated ghrelin concentrations remained suppressed at 1.5 h in EX90 but not EX45. In conclusion, exercise intensity, and to a lesser extent duration, are determinants of the acylated ghrelin response to acute exercise.

Appetite and Energy Intake Responses to Acute Energy Deficits in Females versus Males

Purpose

To explore whether compensatory responses to acute energy deficits induced by exercise or diet differ by sex.

Methods

In experiment one, 12 healthy women completed three 9-h trials (control, exercise-induced (Ex-Def) and food restriction–induced energy deficit (Food-Def)) with identical energy deficits being imposed in the Ex-Def (90-min run, ∼70% of V˙O_2max) and Food-Def trials. In experiment two, 10 men and 10 women completed two 7-h trials (control and exercise). Sixty minutes of running (∼70% of V˙O_2max) was performed at the beginning of the exercise trial. The participants rested throughout the remainder of the exercise trial and during the control trial. Appetite ratings, plasma concentrations of gut hormones, and ad libitum energy intake were assessed during main trials.

Results

In experiment one, an energy deficit of approximately 3500 kJ induced via food restriction increased appetite and food intake. These changes corresponded with heightened concentrations of plasma acylated ghrelin and lower peptide YY_3–36. None of these compensatory responses were apparent when an equivalent energy deficit was induced by exercise. In experiment two, appetite ratings and plasma acylated ghrelin concentrations were lower in exercise than in control, but energy intake did not differ between trials. The appetite, acylated ghrelin, and energy intake response to exercise did not differ between men and women.

Conclusions

Women exhibit compensatory appetite, gut hormone, and food intake responses to acute energy restriction but not in response to an acute bout of exercise. Additionally, men and women seem to exhibit similar acylated ghrelin and PYY_3–36 responses to exercise-induced energy deficits. These findings advance understanding regarding the interaction between exercise and energy homeostasis in women.

Total PYY and GLP-1 responses to submaximal continuous and supramaximal sprint interval cycling in men

Exercise-induced changes in appetite-regulating hormones may be intensity-dependent, however a clear dose-response relationship has not been established. The purpose of this study was to examine changes in anorexigenic markers (total PYY and GLP-1) in response to rest or exercise at submaximal and supramaximal intensities. Ten active males completed four experimental sessions in randomized order: 1) Moderate intensity continuous training (MICT; 30 min cycling at 65% VO_2max); 2) High intensity continuous training (HICT; 30 min cycling at 85% VO_2max); 3) Sprint interval training (SIT; 6 × 30 s "all-out" cycling bouts with 4 min recovery periods); 4) Control (CTRL; no exercise). Blood samples were obtained immediately pre- and post-exercise, as well as 90-min post-exercise for the measurement of total PYY and GLP-1. Subjective hunger was assessed using a visual analog scale pre-breakfast and at the three blood sampling time-points. Total PYY concentrations increased immediately post-exercise following both HICT (P = 0.006) and SIT (P < 0.001) versus CTRL, while SIT was also greater (P = 0.005) compared to MICT. Total GLP-1 concentrations changed similarly across time-points (P < 0.001), with no differences between sessions (P = 0.280). Perceptions of hunger also changed similarly across time-points (P < 0.001) with no differences between trials (P = 0.085). These findings suggest that total PYY increases only after high-intensity exercise and exhibits a greater responsiveness to SIT compared to moderate-intensity exercise. Compensatory increases in hunger do not seem to occur at any exercise intensity. These findings support a dose-response relationship between exercise intensity and total PYY, though the effects on total GLP-1 and hunger perceptions seem unclear.

A functional variant of TLR10 modifies the activity of NFkB and may help predict a worse prognosis in patients with rheumatoid arthritis

Background

Toll-like receptor (TLR) family members are key players in inflammation. TLR10 has been poorly studied in chronic inflammatory disorders, and its clinical relevance in rheumatoid arthritis (RA) is as yet unknown. We aimed at identifying TLR10 variants within all coding regions of the gene in patients with RA as well as studying their functional and clinical significance.

Methods

TLR10 gene variants were studied by performing sequencing of 66 patients with RA and 30 control subjects. A selected variant, I473T, was then analyzed in 1654 patients and 1702 healthy control subjects. The capacity of this TLR10 variant to modify the transcriptional activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) was determined by using a luciferase reporter assay and analyzing the expression of NFkB target genes by quantitative polymerase chain reaction. Differences between groups were analyzed by using the Mann-Whitney U test and the unpaired two-tailed Student’s t test.

Results

We detected ten missense variants in the TLR10 gene and focused on the I473T substitution based on allele frequencies and the predicted functional impact. I473T variant is not associated with susceptibility to RA, but it significantly correlates with erosive disease in patients seropositive for antibodies to citrullinated protein antigens (p = 0.017 in the total cohort and p = 0.0049 in female patients) and with a lower response to infliximab treatment as measured by the change in Disease Activity Score in 28 joints (p = 0.012) and by the European League Against Rheumatism criteria (p = 0.049). Functional studies showed that TLR10 reduced activation of the NFkB inflammatory pathway in hematopoietic cells, whereas the I473T variant lacked this inhibitory capacity. Consistently, after exposure to infliximab, cells expressing the I437T variant showed higher NFkB activity than cells carrying wild-type TLR10.

Conclusions

A TLR10 allelic variant, I473T, has impaired NFkB inhibitory activity and is highly associated with disease severity and low response to infliximab in patients with RA.

Test-meal palatability is associated with overconsumption but better represents preceding changes in appetite in non-obese males

Single-course, ad libitum meals are recommended for the assessment of energy intake within appetite research. This study represents the first investigation of the comparative sensitivity of two single-course, ad libitum meals designed to differ in palatability. We conducted two experiments using a preload study design. All protocols were identical except for the energy content of the preloads (Expt 1: 579 and 1776 kJ; Expt 2: 828 and 4188 kJ). During each experiment, ten healthy men completed four experimental trials constituting a low- or high-energy preload beverage, a 60-min intermeal interval and consumption of a pasta-based or a porridge-based, ad libitum meal. Appetite ratings were measured throughout each trial, and palatability was assessed after food consumption. Preload manipulation did not influence appetite (P=0·791) or energy intake (P=0·561) in Expt 1. Palatability and energy intake were higher for the pasta meal than for the porridge meal in both experiments (palatability P≤0·002; energy intake P≤0·001). In Expt 2, consumption of the high-energy preload decreased appetite (P=0·051) and energy intake (P=0·002). Energy compensation was not significantly different between pasta and porridge meals (P=0·172), but was more strongly correlated with preceding changes in appetite at the pasta meal (r -0·758; P=0·011) than the porridge meal (r -0·498; P=0·143). The provision of a highly palatable, pasta-based meal produced energy intakes that were more representative of preceding appetite ratings, but the moderately palatable, porridge-based meal produced more ecologically valid energy intakes. Ad libitum meal selection and design may require a compromise between sensitivity and ecological validity.

Energy homeostasis and appetite regulating hormones as predictors of weight loss in men and women

Sex differences in weight loss are often seen despite using the same weight loss program. There has been relatively little investigation of physiological influences on weight loss success in males and females, such as energy homeostasis and appetite regulating hormones. The aims were to 1) characterise baseline plasma leptin, ghrelin and adiponectin concentrations in overweight and obese males and females, and 2) determine whether baseline concentrations of these hormones predict weight loss in males and females. Subjects were overweight or obese (BMI 25-40 kg/m(2)) adults aged 18-60 years. Weight was measured at baseline, and after three and six months participation in a weight loss program. Baseline concentrations of leptin, adiponectin and ghrelin were determined by enzyme-linked immunosorbent assay (ELISA). An independent t-test or non-parametric equivalent was used to determine any differences between sex. Linear regression determined whether baseline hormone concentrations were predictors of six-month weight change. Females had significantly higher baseline concentrations of leptin, adiponectin and unacylated ghrelin as well as ratios of leptin:adiponectin and leptin:ghrelin. The ratio of acylated:unacylated ghrelin was significantly higher in males. In males and females, a higher baseline concentration of unacylated ghrelin predicted greater weight loss at six months. Additionally in females, higher baseline total ghrelin predicted greater weight loss and a higher ratio of leptin:ghrelin predicted weight gain at six months. A higher pre-weight-loss plasma concentration of unacylated ghrelin is a modest predictor of weight loss success in males and females, while a higher leptin:ghrelin ratio is a predictor of weight loss failure in females. Further investigation is required into what combinations and concentrations of these hormones are optimal for weight loss success.

Diet-induced changes in maternal gut microbiota and metabolomic profiles influence programming of offspring obesity risk in rats

Maternal obesity and overnutrition during pregnancy and lactation can program an increased risk of obesity in offspring. In this context, improving maternal metabolism may help reduce the intergenerational transmission of obesity. Here we show that, in Sprague-Dawley rats, selectively altering obese maternal gut microbial composition with prebiotic treatment reduces maternal energy intake, decreases gestational weight gain, and prevents increased adiposity in dams and their offspring. Maternal serum metabolomics analysis, along with satiety hormone and gut microbiota analysis, identified maternal metabolic signatures that could be implicated in programming offspring obesity risk and highlighted the potential influence of maternal gut microbiota on maternal and offspring metabolism. In particular, the metabolomic signature of insulin resistance in obese rats normalized when dams consumed the prebiotic. In summary, prebiotic intake during pregnancy and lactation improves maternal metabolism in diet-induced obese rats in a manner that attenuates the detrimental nutritional programming of offspring associated with maternal obesity. Overall, these findings contribute to our understanding of the maternal mechanisms influencing the developmental programming of offspring obesity and provide compelling pre-clinical evidence for a potential strategy to improve maternal and offspring metabolic outcomes in human pregnancy.

Altered gut and adipose tissue hormones in overweight and obese individuals: cause or consequence?

The aim of this article is to review the research into the main peripheral appetite signals altered in human obesity, together with their modifications after body weight loss with diet and exercise and after bariatric surgery, which may be relevant to strategies for obesity treatment. Body weight homeostasis involves the gut–brain axis, a complex and highly coordinated system of peripheral appetite hormones and centrally mediated neuronal regulation. The list of peripheral anorexigenic and orexigenic physiological factors in both animals and humans is intimidating and expanding, but anorexigenic glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY) and orexigenic ghrelin from the gastrointestinal tract, pancreatic polypeptide (PP) from the pancreas and anorexigenic leptin from adiposites remain the most widely studied hormones. Homeostatic control of food intake occurs in humans, although its relative importance for eating behaviour is uncertain, compared with social and environmental influences. There are perturbations in the gut–brain axis in obese compared with lean individuals, as well as in weight-reduced obese individuals. Fasting and postprandial levels of gut hormones change when obese individuals lose weight, either with surgical or with dietary and/or exercise interventions. Diet-induced weight loss results in long-term changes in appetite gut hormones, postulated to favour increased appetite and weight regain while exercise programmes modify responses in a direction expected to enhance satiety and permit weight loss and/or maintenance. Sustained weight loss achieved by bariatric surgery may in part be mediated via favourable changes to gut hormones. Future work will be necessary to fully elucidate the role of each element of the axis, and whether modifying these signals can reduce the risk of obesity.

Persimmon vinegar ripening with the mountain-cultivated ginseng ingestion reduces blood lipids and lowers inflammatory cytokines in obese adolescents

[Purpose]

This study investigated the effect of the vinegar, which is made of 4-year-old mountain-cultivated ginseng ripened into 4-year-matured persimmon vinegar, on the blood lipids level and inflammatory cytokines concentration in obese female adolescents.

[Methods]

Subjects ingested the vinegar, so-called 'mountain-cultivated ginseng persimmon vinegar (MPV)', without meals every day for 6 weeks with activities control. Subjects were grouped into control (CON), persimmon vinegar (PV), and MPV with 10 people in each group. Blood lipids, triglyceride (TG), total-cholesterol (TC), and high density lipoprotein-cholesterol (HDL-C) were analyzed. Also, glutamic oxaloacetic transaminase (GOT) and glutamate pyruvate transaminase (GPT) were analyzed for the hepatotoxicity. Blood cytokines, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) were analyzed.

[Results]

Subjects showed a high reduction in body weight and body fat. Their blood lipid level was effectively improved, and the secretion of inflammatory cytokine was suppressed as well, except for TNF-α. However, the change ratio of the cytokines was high in PV and MPV. Such results were similar to those from research subjects who took persimmon vinegar only (PV), but the effect of the vinegar (MPV) was more remarkable. Besides, this mixture was found to have no effect on the hepatotoxicity.

[Conclusion]

The significance of this study is that all the experiments were conducted without controlling research subjects' daily lives, and it is suggested that the vinegar may be recommended as a kind of health supplement food to suppress obesity. Especially, since these two products are traditional foods of Korean people, which have been taken for ages, it is expected that the fusing of two foods may be better applied to ordinary people who are concerned about obesity.