Dual-process action of exercise on appetite control: increase in orexigenic drive but improvement in meal-induced satiety.
BACKGROUND
Exercise could contribute to weight loss by altering the sensitivity of the appetite regulatory system.


OBJECTIVE
The aim of this study was to assess the effects of 12 wk of mandatory exercise on appetite control.


METHODS
Fifty-eight overweight and obese men and women [mean (+/-SD) body mass index (in kg/m(2)) = 31.8 +/- 4.5, age = 39.6 +/- 9.8 y, and maximal oxygen intake = 29.1 +/- 5.7 mL . kg(-1) . min(-1)] completed 12 wk of supervised exercise in the laboratory. The exercise sessions were designed to expend 2500 kcal/wk. Subjective appetite sensations and the satiating efficiency of a fixed breakfast were compared at baseline (week 0) and at week 12. An Electronic Appetite Rating System was used to measure subjective appetite sensations immediately before and after the fixed breakfast in the immediate postprandial period and across the whole day. The satiety quotient of the breakfast was determined by calculating the change in appetite scores relative to the breakfast's energy content.


RESULTS
Despite large variability, there was a significant reduction in mean body weight (3.2 +/- 3.6 kg), fat mass (3.2 +/- 2.2 kg), and waist circumference (5.0 +/- 3.2 cm) after 12 wk. The analysis showed that a reduction in body weight and body composition was accompanied by an increase in fasting hunger and in average hunger across the day (P < 0.0001). Paradoxically, the immediate and delayed satiety quotient of the breakfast also increased significantly (P < 0.05).


CONCLUSIONS
These data show that the effect of exercise on appetite regulation involves at least 2 processes: an increase in the overall (orexigenic) drive to eat and a concomitant increase in the satiating efficiency of a fixed meal.
King
Neil A
NA
Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. n.king@qut.edu.au
Caudwell
Phillipa P
PP
Hopkins
Mark
M
Stubbs
James R
JR
Naslund
Erik
E
Blundell
John E
JE
D000273:Adipose Tissue; D000328:Adult; D001066:Appetite / Q000502:physiology; D001069:Appetite Regulation / Q000502:physiology*; D001835:Body Weight; D002149:Energy Intake; D015444:Exercise; D005260:Female; D006801:Humans; D006815:Hunger / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology / Q000628:therapy; D050177:Overweight / Q000503:physiopathology* / Q000628:therapy; D012527:Satiation / Q000502:physiology*; D055105:Waist Circumference / Q000502:physiology; D015431:Weight Loss / Q000502:physiology*