Monounsaturated fat-rich diet reduces body adiposity in women with obesity, but does not influence energy expenditure and substrate oxidation: a parallel randomized controlled clinical trial

Abstract

Background: Obesity is an important and growing health problem whose treatment involves dietary changes. In this context, studying the role of macronutrients in weight loss is required in order to understand which strategies may be applied for weight loss. We aimed to evaluate the effects of diets rich in polyunsaturated (PUFAs) and monounsaturated fatty acids (MUFAs) on resting energy expenditure (REE), substrate oxidation, and weight loss in women with obesity. Methods: Randomized, controlled, single blind, parallel-group clinical trial was conducted for 60 days. Participants (n = 32) were divided into three groups: G1= normocaloric PUFAs-rich diet (12% of total energy expenditure (TEE), 10% of n-6 and up to 2% of n-3); G2= normocaloric MUFAs-rich diet (15–20% TEE); and G3= maintenance of the usual diet. Anthropometric and metabolic variables (REE and substrate oxidation by indirect calorimetry) were evaluated. Results: G2 decreased body weight (−1.92 ± 1.99 kg, P = 0.02), body mass index (BMI) (−0.69 ± 0.70 kg/m2; P = 0.02), waist circumference (WC) (−1.91 ± 1.82 cm; P = 0.02), and body fat (−1.14 ± 1.53 kg; P = 0.04). Conclusion: MUFAs-rich diet reduces body weight, BMI, body fat, and WC. Clinical Trials: NCT02656940. Clinical trial registration: Clinical Trials: NCT02656940.