Bone Mineral Density Changes during Weight Regain following Weight Loss with and without Exercise

Area of Science:

• Gerontology
• Exercise Physiology
• Bone Metabolism

Background:

• Postmenopausal women are at increased risk for bone density loss.
• Weight loss interventions can impact bone mineral density (BMD).
• The role of exercise in mitigating BMD changes during weight cycling is not fully understood.

Purpose of the Study:

• To compare BMD changes over 6 months of weight regain in overweight, postmenopausal women.
• To assess the impact of prior weight loss (WL) with or without aerobic exercise (AEX) on BMD during weight regain.

Main Methods:

• Overweight postmenopausal women (BMI > 25 kg/m²) participated in a 12-month study.
• Intervention included 6 months of WL or AEX + WL, followed by 6 months of ad libitum follow-up.
• Bone mineral density (BMD) and VO₂max were measured using DEXA scans and VO₂max tests at baseline, 6 months, and 12 months.

Main Results:

• Both groups lost ~9% body weight and regained ~2% during the study, losing ~4% appendicular lean mass (ALM).
• Total body and total femur BMD decreased similarly in both groups across the 12 months.
• Greater increases in VO₂max and less ALM loss during WL were associated with reduced BMD loss during weight regain.

Conclusions:

• Bone mineral density (BMD) loss may persist even after weight loss and during subsequent weight regain.
• Maintaining muscle quality and aerobic capacity during weight loss may attenuate bone loss during weight regain.
• Further research is needed to elucidate mechanisms of weight loss-induced bone loss and develop strategies for bone protection in older women.