Objective: to evaluate the effectiveness of dietary counseling focusing on fat reduction (20 g/day) compared to calorie reduction (1000 to 1200 kcal/day) in promoting long-term weight loss in moderately obese women.
Design: One hundred and twenty-two women were randomized to one of the two treatment groups and received intensive dietary counseling in groups of 20 over a period of 18 months.
Results: Among 74 women completing the study, weight losses at 6 months averaged 10.2 lb (n = 39) in the fat counseling group and 8.1 lb (n = 35) in the calorie counseling group. Average weight returned to baseline levels in both groups over the succeeding 12 months despite continued intervention.
Conclusion: Although these data provide little support for the immediate clinical utility of low-fat dietary counseling in obesity treatment, the observation that women in the low-fat group were more compliant with treatment directions, rated the diet as being more palatable, and experienced greater reduction in binge eating scores suggests that this approach warrants further study. In addition, time dependent covariance analysis showed that change in fat intake predicted weight change better than change in total energy intake, thus reinforcing the idea that dietary fat may be an important factor in the etiology and treatment of obesity.