Cardiopulmonary adaptation to exercise after acute weight loss in severely obese subjects

The aim of our study was to investigate the effects on baseline and exercise cardiopulmonary function and metabolic parameters of an acute (3-4 weeks) loss of at least 10% of initial weight in severely obese patients. Eight obese patients, 3 males and 5 females, mean age +/- SEM 42 +/- 6 yrs, body mass index (BMI) > 35 kg.m-2, underwent two cardiopulmonary function tests separated by 3 weeks of very low calorie protein-sparing diet (589 kcal.day-1) and a weight loss of 10% of initial weight (mean 8.43 +/- 0.72 kg). Eight normal subjects, matched for sex and age with the obese patients, served as controls. In the obese subjects, maximal workload (+15 +/- 3.6 W) and maximal oxygen consumption (V' O2) (+188 +/- 40.5 mL.min-1) were significantly increased after weight loss. Interestingly, exercise capacity at anaerobic threshold was not significantly different in obese subjects after weight loss with respect to normal subjects. Our results show that an acute but significant weight loss obtained with a very low calorie diet in obese patients is able to significantly improve maximal V' O2 and V' CO2 at anaerobic threshold. Moreover, this acute weight loss is able to partially reverse all of the cardiopulmonary alterations seen in obese patients both at baseline and during exercise.