Fat-Free Mass
Everything in your body that is not fat — muscles, bones, organs, and water. Preserving it during weight loss is essential.
Plain English
Patient-Friendly Explanation
Fat-Free Mass (FFM) is everything in your body that is not fat — your muscles, bones, organs, and water. Preserving FFM during weight loss is crucial because it keeps your metabolism active and your body strong. Losing weight too quickly often means losing muscle along with fat, which can slow your progress.
Medical
Clinical Definition
Fat-Free Mass comprises all non-adipose tissue components including skeletal muscle, bone mineral content, total body water, and visceral organs. It is metabolically active tissue that accounts for approximately 70-85% of resting energy expenditure, with skeletal muscle being the primary contributor to basal metabolic rate.
Key Insight
Why It Matters
Monitoring FFM changes during weight loss helps your doctor ensure you are losing fat, not muscle. At Accord Medical, we use body composition analysis to track your progress and adjust your programme to preserve lean mass for sustainable results.
Sources
Reviewed against standard medical references.
Medically reviewed by
Family Physician & Registered Acupuncturist, Accord Medical Clinic. MBBS (NUS), Graduate Diploma in Family Medicine (NUS), Graduate Diploma in Acupuncture (Singapore College of TCM).
Last reviewed: August 2026
This page is general health education, not medical advice. Whether any treatment is appropriate for you is a decision made in consultation after assessment.