Ghrelin is an orexigenic hormone secreted from endocrine cells in the stomach and other tissues. Acylation of ghrelin is essential for appetite regulation. Vigorous exercise induces appetite suppression, but this does not appear to be related to suppressed concentrations of total ghrelin. This study examined the effect of exercise and feeding on plasma acylated ghrelin and appetite. Nine male subjects aged 19-25 yr participated in two, 9-h trials (exercise and control) in a random crossover design. Trials began at 0800 in the morning after an overnight fast. In the exercise trial, subjects ran for 60 min at 72% of maximum oxygen uptake between 0800 and 0900. After this, they rested for 8 h and consumed a test meal at 1100. In the control trial, subjects rested for 9 h and consumed a test meal at 1100. Area under the curve values for plasma acylated ghrelin concentration (assessed from venous blood samples) were lower over the first 3 h and the full 9 h of the exercise trial compared with the control trial: 317+/-135 vs. 510+/-186 pg.ml(-1).3 h and 917+/-342 vs. 1,401+/-521 pg.ml(-1).9 h (means+/-SE) respectively (P<0.05). Area under the curve values for hunger (assessed using a visual scale) were lower over the first 3 h of the exercise trial compared with the control trial (P=0.013). These findings demonstrate that plasma acylated ghrelin concentration and hunger are suppressed during running.

Broom DR, Batterham RL, King JA, Stensel DJ. Influence of resistance and aerobic exercise on hunger, circulating levels of acylated ghrelin and peptide YY in healthy males. Am J Physiol Regul Integr Comp Physiol 296: R29 -R35, 2009. First published November 5, 2008 doi:10.1152/ajpregu.90706.2008.-Resistance (muscle strengthening) exercise is a key component of exercise recommendations for weight control, yet very little is known about the effects of resistance exercise on appetite. We investigated the effects of resistance and aerobic exercise on hunger and circulating levels of the gut hormones acylated ghrelin and peptide YY (PYY). Eleven healthy male students: age 21.1 Ϯ 0.3 yr, body mass index 23.1 Ϯ 0.4 kg/m 2 , maximum oxygen uptake 62.1 Ϯ 1.8 ml⅐kg Ϫ1 ⅐min Ϫ1 (means Ϯ SE) undertook three, 8-h trials, 1) resistance exercise: a 90-min free weight lifting session followed by a 6.5-h rest period, 2) aerobic exercise: a 60-min run followed by a 7-h rest period, 3) control: an 8-h rest, in a randomized crossover design. Meals were provided 2 and 5 h into each trial. Hunger ratings and plasma concentrations of acylated ghrelin and PYY were measured throughout. Two-way ANOVA revealed significant (P Ͻ 0.05) interaction effects for hunger, acylated ghrelin, and PYY, indicating suppressed hunger and acylated ghrelin during aerobic and resistance exercise and increased PYY during aerobic exercise. A significant trial effect was observed for PYY, indicating higher concentrations on the aerobic exercise trial than the other trials (8 h area under the curve: control 1,411 Ϯ 110, resistance 1,381 Ϯ 97, aerobic 1,750 Ϯ 170 pg/ml 8 h). These findings suggest ghrelin and PYY may regulate appetite during and after exercise, but further research is required to establish whether exerciseinduced changes in ghrelin and PYY influence subsequent food intake.appetite; obesity; physical activity; weight control BODY WEIGHT IS REGULATED BY a balance between food intake and energy expenditure (19). Exercise is an effective method of increasing energy expenditure (2), and it may, paradoxically, lead to a short-term hunger suppression (6,7,24,28,29). This relationship between exercise and hunger has led investigators to study the role of gut hormones in mediating exerciseinduced hunger changes. The majority of studies have focused on aerobic (cardiovascular) exercise (31), with only three studies examining the effects of resistance (muscle strengthening) exercise, and these have reported contradictory effects (21,33,47). Resistance exercise is a key component of exercise recommendations for weight control (2) and public health (23, 42); thus, it is important to clarify the effects of resistance exercise on hunger and gut hormones.The effect of acute exercise bouts on total plasma ghrelin concentrations is controversial, with studies reporting no changes either during or postexercise (10,15,26,27,32,39,43,45,47), as well as increases (14,17,25,44) and decreases (21,33,48,50). Acylation of ghrelin is thought to be essential for appetite...

Identifying the difference in the barriers and motivators between middle-aged and older adults could contribute toward the development of age-specific health promotion interventions. The aim of this review was to synthesize the literature on the barriers and motivators for physical activity in middle-aged (50–64 years) and older (65–70 years) adults. This review examined qualitative and quantitative studies using the theoretical domain framework as the guiding theory. The search generated 9,400 results from seven databases, and 55 articles meeting the inclusion criteria were included. The results indicate that the barriers are comparable across the two age groups, with environmental factors and resources being the most commonly identified barriers. In older adults, social influences, reinforcement, and assistance in managing change were the most identified motivators. In middle-aged adults, goal-setting, the belief that an activity will be beneficial, and social influences were identified as the most important motivators. These findings can be used by professionals to encourage engagement with and adherence to physical activity.

With the advancement of information technology, wearable healthcare technology has emerged as one of the promising technologies to improve the wellbeing of individuals. However, the adoption of wearable healthcare technology has lagged when compared to other well-established durable technology products, such as smartphones and tablets, because of the inadequate knowledge of the antecedents of adoption intention. The aim of this paper is to address an identified gap in the literature by empirically testing a theoretical model for examining the impact of consumers’ health beliefs, health information accuracy, and the privacy protection of wearable healthcare technology on perceived usefulness. Importantly, this study also examines the influences of perceived usefulness, consumer innovativeness, and reference group influence on the adoption intention of wearable healthcare technology. The model seeks to enhance understanding of the influential factors in adopting wearable healthcare technology. Finally, suggestions for future research for the empirical investigation of the model are provided.

Exercise facilitates weight control, partly through effects on appetite regulation. Single bouts of exercise induce a short-term energy deficit without stimulating compensatory effects on appetite, whilst limited evidence suggests that exercise training may modify subjective and homeostatic mediators of appetite in directions associated with enhanced meal-induced satiety. However, a large variability in responses exists between individuals. This article reviews the evidence relating to how adiposity, sex, and habitual physical activity modulate exercise-induced appetite, energy intake, and appetite-related hormone responses. The balance of evidence suggests that adiposity and sex do not modify appetite or energy intake responses to acute or chronic exercise interventions, but individuals with higher habitual physical activity levels may better adjust energy intake in response to energy balance perturbations. The effect of these individual characteristics and behaviours on appetite-related hormone responses to exercise remains equivocal. These findings support the continued promotion of exercise as a strategy for inducing short-term energy deficits irrespective of adiposity and sex, as well as the ability of exercise to positively influence energy balance over the longer term. Future well-controlled studies are required to further ascertain the potential mediators of appetite responses to exercise.

BackgroundTypically, management of PCOS focuses on lifestyle changes (exercise and diet), aiming to alleviate symptoms, and lower the associated risk of type 2 diabetes and cardiovascular disease. Our objective was to analyse evidence on the effectiveness of exercise in the management of PCOS, when compared to (i) usual care, (ii) diet alone, and (iii) exercise combined with diet, and also exercise combined with diet, compared to (i) control or usual care and (ii) diet alone.MethodsRelevant databases were searched (June 2017) with no time limit for trial inclusion. Eligible trials employed a randomised or quasi-randomised design to measure the chronic effects of exercise, or exercise and diet in women with PCOS.ResultsSearches returned 2390 articles; of those, 27 papers from 18 trials were included. Results are presented as mean difference (MD) and 95% confidence intervals (95% CI). Compared with control, exercise had a statistical effect on change from baseline fasting insulin (MD − 2.44 μIU/mL, 95% CIs − 4.24 to − 0.64; very low-quality evidence), HOMA-IR (− 0.57, − 0.99 to − 0.14; very low-quality evidence), total cholesterol (− 5.88 mg/dL, − 9.92 to − 1.83; low-quality evidence), LDL cholesterol (− 7.39 mg/dL, − 9.83 to − 4.95; low-quality evidence), and triglycerides (− 4.78 mg/dL, − 7.52 to − 2.05; low-quality evidence). Exercise also improved VO2 max (3.84 ml/kg/min, 2.87 to 4.81), waist circumference (− 2.62 cm, − 4.13 to − 1.11), and body fat percentage (− 1.39%, − 2.61 to − 0.18) when compared with usual care. No effect was found for change value systolic/diastolic blood pressure, fasting glucose, HDL cholesterol (all low-quality evidence), or waist-to-hip ratio. Many favourable change score findings were supported by post-intervention value analyses: fasting insulin (− 2.11 μIU/mL, − 3.49 to − 0.73), total cholesterol (− 6.66 mg/dL, − 11.14 to − 2.17), LDL cholesterol (− 6.91 mg/dL, − 12.02 to − 1.80), and VO2 max (5.01 ml/kg/min, 3.48 to 6.54). Statistically lower BMI (− 1.02 kg/m2, − 1.81 to − 0.23) and resting heart rate (− 3.26 beats/min − 4.93 to − 1.59) were also revealed in post-intervention analysis. Subgroup analyses revealed the greatest improvements in overweight/obese participants, and more outcomes improved when interventions were supervised, aerobic in nature, or of a shorter duration. Based on limited data, we found no differences for any outcome between the effects of exercise and diet combined, and diet alone. It was not possible to compare exercise vs diet or exercise and diet combined vs diet.ConclusionStatistically beneficial effects of exercise were found for a range of metabolic, anthropometric, and cardiorespiratory fitness-related outcomes. However, caution should be adopted when interpreting these findings since many outcomes present modest effects and wide CIs, and statistical effects in many analyses are sensitive to the addition/removal of individual trials. Future work should focus on rigorously designed, well-reported trials that make comparisons involving both exercise and...

This study demonstrates that, despite inducing a moderate energy deficit, an acute bout of subjectively paced brisk walking does not elicit compensatory responses in acylated ghrelin, appetite, or energy intake. This finding lends support for a role of brisk walking in weight management.

Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study. Thirteen sedentary (7 female) participants undertook three 5-h trials in random order: (i) uninterrupted sitting (SIT), (ii) seated with 2-min bouts of light-intensity walking every 20 min (SIT + LA), and (iii) seated with 2-min bouts of moderate-intensity walking every 20 min (SIT + MA). A standardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial. Subjective appetite ratings and plasma acylated ghrelin, peptide YY, insulin, and glucose were measured at regular intervals. Area under the curve (AUC) was calculated for each variable. AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting (linear mixed modelling: p > 0.05). Glucose AUC was lower in SIT + MA than in SIT + LA (p = 0.004) and SIT (p = 0.055). There was no difference in absolute ad libitum energy intake between conditions (p > 0.05); however, relative energy intake was lower in SIT + LA (39%; p = 0.011) and SIT + MA (120%; p < 0.001) than in SIT. In conclusion, breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period. Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal.Key words: sedentary behaviour, activity breaks, prolonged sitting, appetite-regulating hormones, acylated ghrelin, energy intake.Résumé : L'interruption périodique de la position assise prolongée peut contrer les effets néfastes sur le métabolisme, mais on ne connait pas les effets sur les hormones de l'appétit et de l'intestin, d'où le but de cette étude. Treize personnes sédentaires dont 7 femmes participent selon un ordre aléatoire à 3 essais d'une durée de 5 h chacun : (i) assis sans interruption (« SIT »), (ii) assis + 2 min de marche de faible intensité toutes les 20 min (« SIT + LA ») et (3) assis + 2 min de marche d'intensité modérée toutes les 20 min (« SIT + MA »). Au début de chaque essai, les participants consomment une boisson-test et, à la fin de chaque essai, ils consomment un repas de pâtes ad libitum. À intervalles réguliers, on évalue la sensation de faim et les concentrations plasmatiques de ghréline acylée, de peptide YY, d'insuline et de glucose. On mesure la surface sous la courbe (« AUC ») de chaque variable. Les valeurs de l'AUC de l'appétit et de la concentration des hormones intestinales ne varient pas lors des pauses actives comparativement à la condition assise sans interruption (modèle linéaire mixte, p > 0,05). L'AUC du glucose est plus petite dans la condition SIT + MA comparativement aux conditions SIT + LA (p = 0,004) et SIT (p = 0,055). D'une condition à l'autre, on ne note pas de différences de quantité absolue d'énergie consommée ad libitum (p > 0,05), mais on note une plus faible q...