The ability of habitual exercise to influence appetite and food intake in response to high- and low-energy preloads in man

The present study tested the hypothesis that habitual exercisers demonstrate an increased accuracy of regulation of food intake in compensation for previous dietary energy intake. Twenty-three lean healthy male subjects were divided into two groups on the basis of their habitual exercise levels: non-exercisers (no exercise sessions/week, n 9), and exercisers (>two exercise sessions of 40 min or more/week, n 14). The appetite response to covert liquid preloads of high (2513 kJ) energy (HE) and low (1008 kJ) energy (LE) was investigated Sixty minutes after the preload subjects were offered an ab libitum buffet-style meal and energy intake (EI) was calculated. Subjective hunger and satiety were assessed throughout using self-rated visual-analogue scales. Buffet EI in non-exercisers was not significantly different following the LE or HE preloads (mean compensation 7 %), but the exercise group significantly reduced their energy intake following the HE, compared with the LE, preload (mean compensation 90 %; P=0.0035). A broadly similar pattern of response was observed for both moderate (two to three sessions/week, n 7) and high exercisers (>four sessions/week, n 7). There were no significant differences between hunger or satiety ratings following HE or LE preloads for either group. However non-exercisers scored significantly higher on their self-ratings of hunger at the start of the study, before preload consumption, compared with the exercisers (P<0.01). These findings demonstrate that habitual exercisers have an increased accuracy of short-term regulation of food intake in compensation for preload manipulation, and provide additional support for advocating regular exercise in the prevention of overweight and obesity.