Objective: To evaluate the effect of the consumption of 70% cocoa dark chocolate, enriched with dehydrated blackberry (Rubus ulmifolius) and β-glucan, administered together with regular and low-fat diets, on anthropometric and biochemical parameters and dietary intake in overweight or obese individuals. Methods: A Randomized Complete Block design with 2 × 2 factorial arrangement was used, comparing four treatments during nine weeks, a Phase III case-control observational clinical study, with a population of 16 students of both sexes aged 19-23 years. Anthropometric measurements (weight, height, waist-hip index, BMI, blood pressure, percentage of total and visceral fat), biochemical parameters (capillary glucose and fat profile: total cholesterol, HDL, LDL, and triglycerides), and intake record by 24-hour recall were evaluated. Results: No significant changes were observed in BMI or blood pressure. Women's waist-to-hip ratio decreased significantly in treatment 2 (P < 0.05). Triglycerides were reduced considerably in treatment 3 (P < 0.02). In the low-fat diet, calorie (P < 0.022), carbohydrate (P < 0.018), protein (P < 0.049), and sodium (P < 0.03) intakes showed significant reductions. Conclusions: Consumption of dark chocolate enriched with blackberry and β-glucans, in the context of a low-fat diet, improved cardiometabolic markers and reduced triglyceride levels and calorie, carbohydrate, protein, and sodium intake. There were no statistically significant differences in body mass index or blood pressure.