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

Abstract

PurposeTo explore whether compensatory responses to acute energy deficits induced by exercise or diet differ by sex.MethodsIn 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˙O2max) 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˙O2max) 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.ResultsIn 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 YY3–36. 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.ConclusionsWomen 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 PYY3–36 responses to exercise-induced energy deficits. These findings advance understanding regarding the interaction between exercise and energy homeostasis in women.

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

“…Exercise-induced anorexia and transient changes in appetite-related hormones have also been demonstrated in response to exercise in women, with reductions in acylated ghrelin, and elevations in PYY and GLP-1 concentrations reported during and in the hours after exercise [32,82]. However, these findings are not universal with some studies suggesting that women do not demonstrate a suppression in appetite [61,83] or changes in appetite-related hormones including acylated ghrelin, PYY and GLP-1 [61,84,85] in response to acute exercise stimuli.…”

“…Appetite perceptions typically return to resting control values within 30 to 60 min of exercise cessation [23,[25][26][27][28][29], and do not stimulate changes in energy or macronutrient intakes on the day of exercise [20,[30][31][32][33][34][35].…”

“…Direct comparisons of acute exercise-induced changes in appetite parameters between the sexes have been explored in five studies to date [32,82,[86][87][88]. An important control feature included in these studies was that female participants completed all trials in the follicular phase of the menstrual cycle to minimise any potential confounding effects on the measured appetite parameters [32,82,[86][87][88].…”

“…An important control feature included in these studies was that female participants completed all trials in the follicular phase of the menstrual cycle to minimise any potential confounding effects on the measured appetite parameters [32,82,[86][87][88]. A single bout of vigorous-intensity exercise (70% VȮ2 peak) has been shown to elicit a similar transient suppression of appetite perceptions in both men and women but did not provoke any changes in ad libitum energy or macronutrient intakes on the day of exercise in either sex, despite males displaying greater absolute intakes [32,87]. intensity cycling (30 min, 65% VȮ2 peak) or sprint interval cycling (6  30 s 'all-out' sprints, 4 min recovery) [82].…”

“…In addition to appetite and energy intake measures, many of these aforementioned studies examined potential sex-based differences in appetite-related hormone responses to exercise [32,82,[86][87][88]. Despite evidence of higher fasted concentrations of acylated ghrelin at baseline in women compared with men [30,32], the acute exercise-induced suppression in acylated ghrelin appears similar between the sexes [32,86,87]. However, the potential modulating effect of sex on satiety concentrations were increased after exercise in women but not men [87], whereas Hazell et al found that total PYY levels immediately after sprint interval cycling were only elevated in men [82].…”