Weight loss with a modified Mediterranean-type diet using fat modification: a randomized controlled trial

BACKGROUND/OBJECTIVES: There is evidence that Mediterranean diets with a high proportion of olive oil and nuts can be effective for weight management and prevention of cardiovascular disease. It might be difficult for populations with other eating habits to follow such diets. Therefore, a modified Mediterranean-type diet using fat modification through neutral and butter-flavored canola oil, walnuts and walnut oil with two portion-controlled sweet daily snacks was tested in Germany. SUBJECTS/METHODS: Randomized waiting-list control study with overweight/grade 1 obese subjects: 12-week self-help modified Mediterranean-type diet, 6 weeks of diet plans and 6 weeks of weight loss maintenance training. Trial duration was 12 months. Intervention group (IG) included 100 participants (average age of 52.4 years, weight 85.1 kg and body mass index (BMI) 30.1 kg/m(2)), waiting-list control group (CG) included 112 participants (52.6 years, 84.1 kg and 30.1 kg/m(2)). RESULTS: Per-protocol weight loss after 12 weeks was 5.2 kg in IG vs 0.4 kg in CG (P <= 0.0001), BMI - 1.8 vs - 0.1 kg/m(2) (P <= 0.0001), waist circumference -4.7 vs -0.9 cm (P <= 0.0001). Triglycerides, total cholesterol and LDL cholesterol improved significantly in IG but not in CG. One-year dropouts: 44% in IG and 53% in CG. Weight loss after 12 months: 4.2 kg (pooled data). CONCLUSION: A five-meal modified Mediterranean-type diet with two daily portion-controlled sweet snacks was effective for weight management in a self-help setting for overweight and grade 1 obese subjects. Fat modification through canola oil, walnuts and walnut oil improved blood lipids even at 12 months.