The metabolic interplay between dietary carbohydrate and exercise and its role in acute appetite-regulation in males: A randomised controlled study.

Understanding the metabolic determinants of post-exercise appetite-regulation would facilitate the development of adjunctive-therapeutics to supress compensatory eating behaviours and improve the efficacy of exercise as a weight loss treatment. Metabolic responses to acute exercise are however dependent on pre-exercise nutritional practices, including carbohydrate intake. We therefore aimed to determine the interactive effects of dietary carbohydrate and exercise on plasma hormonal and metabolite responses and explore mediators of exercise-induced changes in appetite-regulation across nutritional states. In this randomised crossover study, participants completed four 120 min visits: (i) control (water) followed by rest; (ii) control followed by exercise (30 min at ∼75% V̇O2 max); (iii) carbohydrate (75 g maltodextrin) followed by rest; and (iv) carbohydrate followed by exercise. An ad libitum meal was provided at the end of each 120 min visit, with blood sample collection and appetite assessment performed at pre-defined intervals. We found that dietary carbohydrate and exercise exerted independent effects on the hormones GLP-1 (Carbohydrate: 16.8 pmol/L, Exercise: 7.4 pmol/L), ghrelin (Carbohydrate: -48.8 pmol/L, Exercise: -22.7 pmol/L) and glucagon (Carbohydrate: 9.8 ng/L, Exercise: 8.2 ng/L) that were linked to the generation of distinct plasma 1H-NMR metabolic phenotypes. These metabolic responses were associated with changes in appetite and energy intake, and plasma acetate and succinate were subsequently identified as potential novel mediators of exercise-induced appetite and energy intake responses. In summary, dietary carbohydrate and exercise independently influence gastrointestinal hormones associated with appetite regulation. Future work is warranted to probe the mechanistic importance of plasma acetate and succinate in post-exercise appetite-regulation. KEY POINTS: Carbohydrate and exercise independently influence key appetite-regulating hormones Temporal changes in post-exercise appetite are linked to acetate, lactate, and PYY Post-exercise energy intake is associated with GLP-1 and succinate levels Abstract figure legend Our work aimed to explore hormonal and metabolite mediators of exercise-induced changes in appetite and energy intake across nutritional states. Twelve-male participants completed four study visits involving intake of water (control) or carbohydrate with a 30 min rest or high-intensity exercise session. Plasma samples were collected throughout the 120 min study periods to quantify gastrointestinal hormone release and 1H-NMR metabolite profiles. Visual analogue scales were used to investigate appetite responses and an ad libitum meal was provided at the end of each study visit to evaluate energy intake. Temporal changes in acetate, lactate and PYY were associated with supressed appetite responses in both exercise conditions. A consistent negative association between GLP-1 and succinate levels with meal energy intake was found in both exercise conditions. This article is protected by copyright. All rights reserved.