The Claim
Prolonged fasting periods of at least 16 hours, as practiced in intermittent fasting, increase muscle protein breakdown due to reduced insulin levels, resulting in greater net muscle protein loss over a 24-hour period compared to more frequent feeding patterns.
What the research says
Not yet evaluated
We are still looking at what the research says.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Fasting for 16 hours or more increases the rate at which muscle proteins are broken down and reduces net muscle protein retention over 24 hours compared to eating more frequently.
See the scientific wording
Prolonged fasting periods (≥16 hours) characteristic of intermittent fasting may elevate muscle protein breakdown due to low insulin levels, which normally suppress breakdown, potentially increasing net muscle protein loss over 24 hours compared to more frequent feeding.
When no food is eaten for 16 hours or more, insulin levels drop, which removes the signal that normally stops muscle from breaking down. Without insulin, muscle proteins are torn apart into amino acids at a higher rate. These amino acids are not used to build new muscle because protein is not eaten often enough to trigger muscle building. Instead, the excess amino acids are burned for energy and lost from the body, leading to a net loss of muscle over time.
What the research says
1 studyWhen you go a long time without eating, your body breaks down more muscle because insulin drops and can’t stop it. Eating protein only once or twice a day doesn’t rebuild muscle as well as eating it in smaller amounts more often.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.