Metabolic syndrome is a multifactorial inflammatory condition that is very prevalent in overweight women with type 2 diabetes. However, there seems to be great benefit in changing lifestyle and dietary patterns in the treatment of this condition. Currently, few studies have shown the effect of a Dietary Approach to Stop Hypertension (DASH) diet in postmenopausal women with metabolic syndrome and the influence of genetic polymorphisms of the fat mass and obesity-associated protein (FTO) and beta-2 adrenergic receptor (ADRB2) genes on inflammatory markers and improvement of laboratory indicators in these patients. This study aims to analyze the interaction of polymorphisms in the ADRB2 and FTO genes and the DASH diet on anthropometric indicators and laboratory tests in patients with metabolic syndrome in the city of Rio de Janeiro. For this purpose, laboratory tests and anthropometric data will be collected in a prospective study with women aged between 40 and 60 years.

Prospective, single-arm, unblinded clinical trial lasting 90 days. The study population will consist of menopausal women aged between 40 and 60 years who are obese (BMI > 30) and diagnosed with metabolic syndrome. Volunteers will have an in-person consultation with a nutritionist at t0 to assess their previous habitual food intake and will receive a DASH diet. To minimize losses during the study, in-person consultations with a nutritionist will be held at t0, t30, t60, t90, and online consultations (teleconsultation) at t15, t45 and t75 to answer a questionnaire to assess nutritional adherence that the nutritionist will apply. Saliva samples will be collected for genetic panel analysis only at t90. Serum samples for analysis of lipid profile, blood glucose, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), follicle stimulating hormone (FSH), C-reactive protein (CRP) and tumor necrosis factor (TNF) and profile of medications used will be collected at t0 and t90.

Only one nutritionist will make the dietary prescription to maintain the standardization of the research. The diets will be previously calculated, varying from 100 to 100 kcal (1400 to 2600 kcal) based on the patients' total energy value (TEV). The isocaloric, balanced, and individualized diet will be calculated according to the resting metabolic rate (RMR) obtained by the prediction equation and multiplied by the corresponding activity factor to obtain the TEV. The DASH eating plan will consist of fruits, vegetables, legumes, whole grains, and low-fat dairy products. White meat will be prioritized over red meat, seeds and oilseeds will be included, and sweets and foods rich in sodium will be limited.

Dietary assessment will be performed using periodic dietary record forms (24-hour records) for three non-consecutive days, two typical days, and one atypical day, to analyze the participants' eating habits before the dietary intervention. The participants will complete periodic records at seven points before the intervention begins at t15, t30, t45, t60, t75, and at the end of the 90-day study. The nutritionist will review all forms to check for any missing information (number of meals, added sugar, spoon size, quantity consumed, and type of preparation) and notes that could raise questions later (few items recorded, unknown foods, errors in household measurements, and absence of any meal).

Inclusion Criteria:

• The study population will consist of menopausal women aged between 40 to 60 years old
• Obese (BMI > 30) with a diagnosis of MS.

The inclusion criteria are the presence of at least 3 of the 5 criteria* for MS, which include:

• Abnormal waist circumference values (≥89 cm in women)
• SBP ≥120 mm Hg and DBP ≥80 mm Hg) or diagnosis of hypertension
• Fasting blood glucose equal to or greater than 100 mg/dL or diagnosis of DM2
• HDL-c less than 50 mg/dL in women
• Triglycerides ≥150 mg/dL.

Exclusion Criteria:

• Patients with a BMI <25 kg/m2

The following chronic diseases will not be eligible:

• Active cancer
• Active tuberculosis
• Psychiatric illnesses
• Multiple sclerosis
• Severe nephropathy
• Advanced stages of Paget's disease.

These chronic conditions could interfere with the results of this study, especially adherence to diet and weight loss. Patients who do not complete all stages of the study, who are not adhering to the intervention or who present any complication that interferes with the results of the study will be excluded from the study.