The systematic review and meta-analysis titled “Effects of gradual weight loss v. rapid weight loss on body composition and RMR” published in the British Journal of Nutrition
examines how different rates of weight loss—gradual versus rapid—affect body composition and resting metabolic rate (RMR) in individuals with overweight or obesity.
Key Findings:
- Fat Mass (FM) Reduction: Both gradual and rapid weight loss approaches resulted in similar total weight loss. However, gradual weight loss led to a more significant reduction in fat mass, with an average decrease of 1 kg more than rapid weight loss.
- Body Fat Percentage (BFP): Participants undergoing gradual weight loss experienced a greater decrease in body fat percentage, averaging a 0.83% greater reduction compared to those in the rapid weight loss group.
- Resting Metabolic Rate (RMR): Gradual weight loss was associated with better preservation of RMR. Specifically, individuals in the gradual weight loss group maintained an RMR that was approximately 407.48 kJ higher than those in the rapid weight loss group, indicating a lesser decline in metabolic rate.
- Fat-Free Mass (FFM) and Anthropometric Measures: No significant differences were observed between gradual and rapid weight loss groups concerning fat-free mass, waist and hip circumferences, or waist-to-hip ratios.
Conclusion:
The study suggests that while both gradual and rapid weight loss strategies can achieve similar total weight loss, gradual weight loss offers advantages in reducing fat mass and body fat percentage, as well as in preserving resting metabolic rate. These findings support the recommendation of gradual weight loss for individuals aiming to improve body composition and maintain metabolic health.
