Role of resting metabolic rate and energy expenditure in hunger and appetite control: a new formulation

Abstract

A long-running issue in appetite research concerns the influence of energy expenditure on energy intake. More than 50 years ago, Otto G. Edholm proposed that “the differences between the intakes of food [of individuals] must originate in differences in the expenditure of energy”. However, a relationship between energy expenditure and energy intake within any one day could not be found, although there was a correlation over 2 weeks. This issue was never resolved before interest in integrative biology was replaced by molecular biochemistry. Using a psychobiological approach, we have studied appetite control in an energy balance framework using a multi-level experimental system on a single cohort of overweight and obese human subjects. This has disclosed relationships between variables in the domains of body composition [fat-free mass (FFM), fat mass (FM)], metabolism, gastrointestinal hormones, hunger and energy intake. In this Commentary, we review our own and other data, and discuss a new formulation whereby appetite control and energy intake are regulated by energy expenditure. Specifically, we propose that FFM (the largest contributor to resting metabolic rate), but not body mass index or FM, is closely associated with self-determined meal size and daily energy intake. This formulation has implications for understanding weight regulation and the management of obesity.

Modelling the associations between fat-free mass, resting metabolic rate and energy intake in the context of total energy balance

“…Indeed, this attenuation in tonic inhibition with increased FM could contribute to 331 overconsumption in obese individuals, as the drive to eat arising from energy needs, elevated 332 due to a higher RMR, would remain unabated (23). However, the cross-sectional nature of 333 the present study means that inferences cannot be made regarding how systematic changes in 334 body composition or RMR influence EI.…”

“…Importantly, the present findings indicate that the energy expenditure 277 arising from RMR stimulates food intake, and helps account for this excitatory drive. This 278 tonic signal of energy demand would help 'tune' EI to energy expenditure and ensure the 279 execution of key biological processes (23). 280…”

“…Therefore, it has been proposed that FFM, as the main determinant of resting metabolic rate-52 (RMR), drives EI at a level proportional to basal energy requirements (23). In support of this, 53…”

Acute and Chronic Effects of Exercise on Appetite, Energy Intake and Appetite-Related Hormones: the Modulating Effect of Adiposity, Sex and Habitual Physical Activity

“…Further to elevations in energy expenditure and fat oxidation, cross-sectional evidence suggests that exercise may influence energy balance through variations in energy intake [10,11].…”

The Effect of Gum Arabic on Energy Balance Genes in Mouse Liver

“…Energy expenditure was influenced by basal metabolism rate [2], physical activity [3], body size and lifespan [4], and thermogenesis [5]. Disturbances of central [6] and peripheral [7] signals may lead to obesity and anorexia.…”