Prediction of energy requirements of obese patients after massive weight loss.

A regression analysis was made of resting metabolic rate on weight and body composition in 140 women with varying degrees of obesity. In 19 severely obese women before weight loss, average resting metabolic rate was 290 ml O2/min, or 4 per cent higher than predicted from the regression equation. After losing 30 kg in one year the average metabolic rate of this group was 234 ml O2/min, 1 per cent higher than that predicted for their reduced weight. Women whose metabolic rate was high or low relative to prediction before weight loss tended to maintain this status after weight loss (P less than 0.05). There is a close relation between resting metabolic rate and total energy expenditure. We conclude that there is a reduction in energy requirements for weight maintenance after massive weight loss, but the requirements of obese patients after weight loss are similar to those of people of comparable weight who have not reduced.