Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial.

What was studied

A controlled feeding trial tested whether higher protein intake preserved fat-free mass and muscle protein synthesis during a severe short-term calorie deficit.

Who / model studied

Thirty-nine adults were randomized among three protein-intake groups.

Studied dose & schedule

Diets supplied 0.8, 1.6 or 2.4 g protein/kg/day for 31 days: 10 days of weight maintenance followed by 21 days at a 40% energy deficit.

What the study found

All groups lost about 3.2 kg. The two higher-protein groups lost a smaller proportion as fat-free mass and maintained the meal-stimulated anabolic response better than the RDA group.

Limitations & context

The intervention lasted only three weeks in deficit. Fat-free mass is not identical to skeletal-muscle tissue, and the study does not establish long-term effectiveness or safety.

Read summary source ↗ · Prepared 10/6/2026 · AI-assisted, source-based summary