<qa>  What was the MUFA-rich diet?Obesity is a complex disease of multifactorial etiology and difficult to control. Among lifestyle changes proposed to the treatment of this disease and comorbidities, there is the modulation of dietary lipid composition. This study aimed to evaluate the effects of the modulation of fatty acid FA polyunsaturated PUFA and monounsaturated MUFA in energy expenditure EE, weight loss, body composition, lipid and glycemic profile, free fatty acids FFA, glycerol, adiponectin, leptin, blood pressure BP, feeding behavior and expression of PPARα and PPARγ2 genes in adipose tissue AT of obese women. It was conducted a parallel, randomized, controlled, single-blind study with dietary intervention DI for 60 days, where 32 women with obesity classes I and II were distributed into three groups: G1 diet rich in n-3 PUFA and n-6 n 10; G2 MUFA-rich diet n 11; and G3 control n 11. For G1 and G2 were prescribed normocaloric diets with similar macronutrient composition, varying only the type of lipids offered. In order to achieve the desired intake of unsaturated FA, both groups received individual portions of vegetable oils in the form of sachets, which were consumed for lunch and dinner G1 mix of virgin olive oil VOO and soybean oil SO, overall of 35.2g to 52.8g day; G2 VOO, overall of 35.2g to 50.6 g day, besides gelatin capsules G1 2 g of fish oil day; G2 1 capsule of 1g of SO day. G3 was instructed to keep their eating habits and consuming placebos 1 sachet of 2g of SO and 1 capsule of 1g of SO day. 