Energy expenditure and body composition during weight reduction in hyperplastic obese women.

The energy expenditure and body composition changes in out-patients during a long-term weight reduction with a diet recommended to provide 1100 kcal were studied in eight hyperplastic obese women. The study was focused on finding plausible explanations for the decreasing weight loss rate after several weeks of successful weight reduction. Using a heart rate monitoring method, the energy expenditure was measured four times at selected intervals during the study. Then, the energy intake was calculated on the basis of three dietary recordings lasting from 4 to 7 days. The recorded energy intake increased at the end of the weight reduction, but no changes in daily energy expenditure were found. The oxygen consumption during standardized cycling, walking, and domestic work decreased, but when the patient was at rest, no changes occurred during the weight reduction. The weight loss predicted from the energy balance and body composition changes was considerably greater than the actually determined weight loss. Large discrepancies were found after 5 weeks on the weight reducing regimen between the recorded dietary intake and what could be calculated from urinary nitrogen losses. With the available methods for determining energy intake and expenditure, it was considered impossible to fully explain the reason for the weight plateau observed after long-term weight reduction in out-patients.