Short- and long-term effects of continuous versus intermittent restrictive diet approaches on body composition and the metabolic profile in overweight and obese postmenopausal women: a pilot study.

OBJECTIVE: The objective of this study was to compare changes in body composition and the metabolic profile between women taking an intermittent diet (ID) and women taking a continuous diet (CD).

METHODS: Twenty-five obese postmenopausal women were randomized to an ID (n = 13) or a CD (n = 12). In the ID, 5-week energy restriction periods were followed by 5-week weight stabilization periods. In the CD, 15 weeks of energy restriction was followed by 5 weeks of weight stabilization. Outcome measures before, during, and after weight loss, as well as after a 1-year follow-up, were body weight and composition, waist circumference, resting metabolic rate, and fasting lipid and glucose levels.

RESULTS: Body weight, waist circumference, percentage fat mass, and fat mass decreased significantly and similarly in both groups (P < 0.0001). Both groups showed similar overall decreases in plasma total cholesterol and triglycerides (all P < 0.05). Low-density lipoprotein cholesterol improved significantly in the CD group only, whereas fasting glucose decreased significantly in the ID group only. High-density lipoprotein cholesterol and resting metabolic rate remained stable in both groups. Fasting plasma triglyceride and glucose levels were the only metabolic variables to further improve after the fifth week of the protocol. At the 1-year follow-up, both interventions were associated with successful and similar weight loss maintenance and improvements in fasting plasma glucose levels.

CONCLUSIONS: The ID resulted in similar short- and long-term changes in body composition and metabolic profile compared with a CD. Most improvements occurred during the first 5 weeks of treatment in both interventions.