Yerba mate (Ilex paraguariensis), a traditional drink consumed in different parts of the word, but especially in southern Brazil, is an importante source of polyphenols and has a high antioxidant potencial, With a moderate content of methylxanthines, yerba mate has stood out for its promising effects in modulating metabolic pathways in pre-clinical models. However, its beneficial effets in clinical trials have yet to be elucidated. Overweight and chronic non-communicable diases are urgent public health conditions and reducing the risk of these conditions through food sources is one of the most sustainable approaches. This study aims to evaluate the impact of a standardized extract of yerba mate on nutritional, biochemical, metabolic, inflammatory and antioxidant status parameters in overweight individuals compared to a placebo. A double-blind, parallel, randomized, placebo- controlled clinical trial will be conducted involving 80 overweight individuals. The subjects will receive an encapsulated yerba mate extract totaling 2,250 mg or a corresponding placebo, fractionated three times a day. This amount was defined according to previous studies thet estimated the habitual intake of yerba mate in the form of chimarrão or tererê by adults in a city in the southern region of the country. Anthropometric measurements, composition, blood pressure and blod and stool samples will be collected for nutritional assessment, metabolic and inflammatory parameters and antioxidant status assessment on days 0 and 90. The data will be analyzed descriptively and inferentially. Differences in the individuals characteristics at baseline and comparisons between groups will be aseessed using the difference of means test (depending on the normality of the data) and chi-square or Fisher-s exact test for categorical variabes, In addition, to compare the effect of the intervention between the groups, a two-way analysis of covariance will be used. A 5% significance level will be adopted. It is expect to find positive effects of yerba mate extract on the parameters assessed.

Inclusion Criteria:

1. men and women;
2. aged between 40 and 65 years;
3. with no previous cardiovascular history;
4. individuals who are non-smokers or who have stopped smoking in the last 3 years;
5. individuals who agree to maintain a habitual diet and physical activity;
6. individuals who agree to maintain habitual consumption of polyphenol-rich beverages (yerba mate, teas, coffee, wine, cocoa, soy milk and fruit juice) during the course of the study;
7. individuals who are not taking hypoglycemic, antihypertensive or anticholesterolemic drugs and;
8. individuals who are overweight or obese (BMI≥25 to 34 Kg/m2 );
9. individuals who have given up nutritional monitoring at least 3 months or who are undergoing nutritional treatment, but who are not showing weight changes of >5% in the last 3 months.

Exclusion Criteria:

1. diagnosis uncontrolled metabolic or endocrine pathologies;
2. who have undergone obesity surgery;
3. post-menopausal women;
4. pregnant and breastfeeding women;
5. use of antipsychotics;
6. with a vegetarian or vegan diet;
7. who use probiotics and food supplements with antioxidant characteristics;
8. those who have had a weight change of more than 10% in the last 3 months; 9) in treatment for excess body weight (hypocaloric diet or current nutritional treatment);

10) smokers or chronic alcoholics; 11) Severe hypertension, history of cardiovascular disease with clinical complications such as: acute myocardial infarction and other coronary heart disease; 12) individuals with known malignant neoplasms, gastrointestinal diseases, kidney disease and/or liver disease.