Efficacy and Feasibility of an Intermittent Weight Loss Program.

The goal of the study is to measure the effect of an approach including phases of active weight loss broken by weight stabilisation periods (named intermittent weight loss) on the metabolic profile. First, the intermittent weight loss approach will contribute to create an artificial transitory steady state during the weight loss treatment that will help to minimize the adverse effects of the standard approach on muscle mass and resting metabolic rate. Second, despite a comparable fat mass loss, the intermittent weight loss approach will improve the metabolic profile to a greater degree compared to the standard approach. Finally, the intermittent weight loss approach will be associated with less weight regain after the treatment since the beneficial effect on muscle mass and metabolic rate.

Excessive levels of body fat are associated with metabolic disturbances predictive of an increased risk of coronary heart disease (CAD). It is presently unclear as to the magnitude of weight loss needed to accrue metabolic benefits. Despite the effectiveness of weight loss to reduce obesity levels, studies have shown that only minor decreases in body weight (5-10%) are needed to clinically improve CAD risk factors. Our data suggested that a 10% reduction in body weight is as effective in improving the metabolic profile as a 20% decrease in body weight. Thus, the question are : " Is it possible to further improve the metabolic profile over that 5-10% weight loss threshold?" and "Could several 5-10% body weight loss (intermittent weight loss approach) have additive effects on the metabolic profile?". We would like to follow-up on these observation to better understand 1) the association between weight loss and improvements in the metabolic profile and 2) why minor decreases in body composition and body fat distribution are as effective as more important reduction.

Body composition (fat mass and lean body mass): after 0, 5, 10, 15, 20 and 25 weeks, as well as 12-month post-intervention

Inclusion Criteria: Women who had stopped menstruating for more than 1 year Waist circumference > 90 cm Sedentary (< 2 times a week of structured exercise) Non-smokers Low to moderate alcohol consumers (< 2 drinks per day). Exclusion Criteria: We excluded subjects with the following conditions based on medical history and physical examination and on laboratory testing of kidney and liver functions, serum TSH, fasting glucose and lipid profile, and 75g-OGTT Cardiovascular disease, peripheral vascular disease or stroke Diabetes Moderate to severe hypertension (resting blood pressure > 170/100 mm Hg); Body weight fluctuation > 5 kg in the previous 6 months Thyroid or pituitary disease Hormonal replacement therapy at any time during the previous 6 months Medication that could affect the metabolic profile