Metabolic fitness in active reduced-obese individuals

To verify whether a physical activity-low-fat diet follow-up could normalize the metabolic risk profile of reduced-obese men and women having undergone considerable weight loss through energy restriction and drug therapy.

Twenty obese individuals (12 men, 8 women) participated in a weight-reducing program that included two phases. In the first phase, a non-macronutrient-specific dietary restriction of about 700 kcal/day was prescribed to induce weight loss over 15 weeks, with either fenfluramine or placebo. The second phase consisted of a physical activity-low-fat diet follow-up that was maintained as long as subjects did not experience resistance to further body weight and fat loss. Resistance to lose fat occurred after a mean cumulative fat loss of 14 and 8 kg in men and women, respectively.

Despite this substantial decrease in body fat, subjects' adiposity remained much higher at the end of this protocol than values observed in lean control subjects. However, fasting plasma levels of insulin, cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, and triglyceride as well as the response of insulin and glucose to oral glucose were normalized at the end of the physical activity-low-fat diet follow-up.

These results indicate that further weight and fat losses may not be justified when a moderate body weight loss resulting in a highly favorable improvement of metabolic risk profile is achieved in patients who would have still been diagnosed as overweight or obese on the basis of criteria currently promoted by public health agencies.