The Claim
A fat loss rate of one pound per week can be achieved without concurrent loss of skeletal muscle mass in humans.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
People can lose one pound of fat each week while keeping all their muscle mass unchanged.
See the scientific wording
A rate of one pound of fat loss per week is achievable without concomitant muscle loss.
When a person loses fat by eating fewer calories, their muscles would normally break down, but if they lift weights and eat enough protein, the force from lifting and the amino acids from protein keep the muscles building new proteins at the same rate they break down, so muscle mass stays the same.
What the research says
4 studiesPeople who ate a special protein supplement lost mostly fat and kept almost all their muscle while dieting — even though they didn't lose a full pound of fat every week, they lost a lot of fat without losing much muscle, which shows it's possible to do so.
When people eat more protein and lift weights while dieting, they can lose over a pound of fat per week and keep almost all their muscle. Without exercise and less protein, they lose more muscle.
People lost fat while their thigh muscles actually got bigger, proving you can lose weight without losing muscle — and maybe even build a little muscle at the same time.
Related videos
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 4 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.