Energy Depletion by 24-hr Fast Leads to Compensatory Appetite Responses Compared to Matched Energy Depletion by Exercise in Healthy Young Males

David Thivel ¹ Graham Finlayson ² Maud Miguet ¹ Bruno Pereira ³ Martine Duclos ³ Yves Boirie ³ Eric Doucet ⁴ John Blundell ² Lore Metz ¹

¹Clermont Auvergne University, Clermont-Ferrand, France
²University of Leeds, Leeds, UK
³Clermont-Ferrand University Hospital, Clermont-Ferrand, France
⁴University of Ottawa, Ottawa, Canada

Background: There is a currently growing interest regarding the distinct effects of similar (iso-energetic) energy deficits induced by dietary restriction versus physical exercise on energy balance. According to the available evidence, food restriction will favor increased appetite feelings and energy intake whereas similar exercise-induced energy depletion will not lead to such energy compensations among both lean and obese individuals. Although intermittent fasting, as a newly popular weight loss strategy that consists of total daily energy depletion induced through food restriction, has been shown to favor increased appetite and energy intake on the following days, it remains unknown whether a similar severe daily deficit induced by exercise leads to such nutritional compensatory responses.

Aims: To compare appetite, energy intake and food reward responses to an energy depletion induced either by 24-h food restriction or an equivalent deficit with exercise in healthy males.

Methods: Twelve healthy lean males (21.5±0.5 years-old; BMI: 22.5±1.7kg/m²) participated. Body composition, aerobic capacity, food preferences and energy intake were assessed. They randomly realized three conditions: 1) no depletion (CON); 2) full 24-h energy restrictions (Def-EI); 3) exercise condition (Def-EX). Ad libitum energy intake and food reward were assessed at the end of each session. Appetite feelings were assessed regularly.

Results: Ad libitum energy intake was higher on Def-EI (1752±711kcal) compared to CON (1267±288kcal) (p0.05), with no difference between CON and Def-EX(1491±416kcal). There was no difference in the percent energy ingested from macronutrients. Hunger was lower on CON and Def-EX compared to Def-EI(p0.001). Satiety was higher on CON and Def-EI versus Def-EX (P0.001). Taste Bias for Implicit Wanting, Food Choice, Explicit Wanting and Explicit Liking was lower after the test meals in each condition (p0.001). There was a significant interaction condition x time between CON and Def-EI for Food Choice Fat Bias (p0.05) and between Def-EI and CON (p0.01) and Def-EI and Def-EX (p0.05) for Explicit Wanting Taste Bias.

Discussion and Conclusion: While 24-hr fasting leads to increased energy intake in the following meal, increased hunger profile and decreased post-meal food choice fat bias, such nutritional responses are not observed after a similar deficit induced by exercise.

Prof. David Thivel

Clermont Auvergne University

David Thivel (PhD, HDR) is Associate Professor in Exercise Physiology and Human Nutrition at Clermont-Auvergne University in France. He completed a PhD at the National Institute for Agronomic Research (INRA) in Clermont-Ferrand University and in the Laboratory of Exercise Physiology (BAPS) in Clermont-Ferrand where he examined the effects of acute exercises on the control of energy intake and appetite in adolescents with obesity. He then held two post-doctoral positions, the first one at the NY Obesity Nutrition Research Center in Columbia University, USA, and another one at the Healthy Active Living and Obesity Research Institute of Ottawa in Canada. David’s main research focuses on the metabolic and nutritional responses to energy deficits induced either by exercise and/or dietary restriction, in both children and adults with obesity. He is currently leading the research program "Physiological and Nutritional Adaptations to Energy Deficits" at the AME2P Laboratory, CRNH Auvergne in France. Dr. David Thivel is also Vice-President of the Obesity Specialized Center Caloris and of the European Childhood Obesity Group.