Body Composition Differences Between Excess Weight Loss ≥ 50% and < 50% at 12 Months Following Bariatric Surgery

Area of Science:

• Bariatric Surgery Outcomes
• Body Composition Analysis
• Metabolic and Endocrine Disorders

Background:

• The impact of bariatric surgery on body composition remains unclear.
• Understanding body composition changes is crucial for long-term patient health post-surgery.

Purpose of the Study:

• To compare body composition changes between patients with excess weight loss (EWL) ≥ 50% and < 50% at 12 months post-bariatric surgery.
• To analyze trajectories of body mass index (BMI), fat mass (FM), lean body mass (LBM), and skeletal muscle index (SMI).

Main Methods:

• Prospective cohort study of 37 patients undergoing bariatric surgery.
• Body composition measured via dual-energy X-ray absorptiometry pre-operatively and at 1, 6, and 12 months post-operatively.
• Analysis of BMI, FM, LBM, and SMI in groups with EWL ≥ 50% and EWL < 50%.

Main Results:

• The EWL ≥ 50% group had a more favorable fat mass to lean body mass loss ratio.
• Patients with EWL ≥ 50% lost significantly more fat mass per kg of lean body mass lost.
• A significant increase in skeletal muscle index percentage was observed in the EWL ≥ 50% group (5.5% vs. 2.4%).
• The majority of lean body mass reduction (67.4%) occurred within the first month post-surgery.

Conclusions:

• Achieving ≥ 50% excess weight loss is associated with superior body composition outcomes post-bariatric surgery.
• Lean body mass loss is most pronounced in the early post-operative period, highlighting the need for targeted interventions.