Effects of Resistance Training Combined with a Ketogenic Diet: A Systematic Review and Meta-Analysis

Weight loss treatments require adherence to physical exercise and diet. Restrictive diets have been proposed for obesity treatment, including a ketogenic diet that are high in lipids, moderate in proteins, and low in carbohydrates. In recent years, there has been criticism of this diet because of the reduction in fat-free mass and, consequently, a reduction in basal energy expenditure, which is considered negative in obesity treatment. However, resistance training is known to promote skeletal muscle hypertrophy. The hypothesis for this review was: "Resistance training is sufficient to maintain lean mass during diets that cause ketosis." Despite the slight reduction in lean mass identified in the meta-analysis, some authors reported no loss in physical performance. Others suggested that this difference in lean mass is associated with water loss in the participants, which aligns with a few studies that reported a final phase with carbohydrate reintroduction into the diet. Our results indicated physical exercise was an important tool for maintaining lean mass in individuals who consumed carbohydrate-restricted diets that cause ketosis. Keywords: high-fat diet; carbohydrate-restricted diet; body composition; physical activity; muscle hypertrophy.