No differences in rates of energy expenditure between post-obese women and their matched, lean controls

Rates of energy expenditure at rest, during different daily activities and following a standardized liquid meal were compared in eight post-obese women, with a mean weight loss of 21.5 kg (range 14.1 to 33.3 kg) and eight controls who had never been overweight. Age, height, body mass index, fat-free mass and average daily energy intake were similar for both experimental groups. Resting metabolic rate averaged 23.04 cal/min/kg FFM (s.e.m. 1.14) in the post-obese and 22.70 cal/min/kg FFM (s.e.m. 0.64) in the controls on their first visit to the laboratory. Metabolic rates in the two groups rose in parallel as energy expenditure was increased by sitting, standing and walking at three different speeds (2.4, 3.9 and 5.4 km/h). At the highest walking speed energy expenditure averaged 95.30 cal/min/kg FFM (s.e.m. 4.18) in the post-obese and 93.42 cal/min/kg FFM (s.e.m. 2.97) in the control women. Comparisons of postprandial thermogenesis revealed no significant differences between the two groups. The results of the present study do not support the thesis that rates of energy expenditure, whether at rest, during different activities, or after eating, are reduced in post-obese women.