Why protein shakes don't build muscle when you're starving
Protein synthesis signaling in skeletal muscle is refractory to whey protein ingestion during a severe energy deficit evoked by prolonged exercise and caloric restriction
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Whey protein increased plasma BCAA and EAA but failed to activate anabolic signaling — specifically reducing pSer9GSK3β — despite contractile activity.
Common belief: More amino acids in blood = more muscle growth. This shows the body can block that signal entirely during extreme calorie deficit.
Practical Takeaways
Avoid extreme calorie deficits (like 5,500 kcal/day) if preserving muscle is a priority — even with whey protein, your muscles won't respond.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Whey protein increased plasma BCAA and EAA but failed to activate anabolic signaling — specifically reducing pSer9GSK3β — despite contractile activity.
Common belief: More amino acids in blood = more muscle growth. This shows the body can block that signal entirely during extreme calorie deficit.
Practical Takeaways
Avoid extreme calorie deficits (like 5,500 kcal/day) if preserving muscle is a priority — even with whey protein, your muscles won't respond.
Publication
Journal
International Journal of Obesity
Year
2018
Authors
Marcos Martin‐Rincon, I. Perez‐Suarez, Alberto Pérez‐López, J. Ponce-González, D. Morales‐Alamo, P. de Pablos-Velasco, H. Holmberg, J. Calbet
Related Content
Claims (4)
When people eat way less food and exercise a lot for a few days, their body lowers the hormones that help build muscle and raises the stress hormone, which may explain why their muscles stop growing even if they eat protein.
Even when people eat whey protein during extreme dieting and lots of exercise, their muscles stop responding to it like they normally would — the protein doesn’t trigger the usual growth signals.
Even when the body is in starvation mode, one specific part of the muscle growth system (4E-BP1) becomes more active — which is confusing because other parts are shutting down.
Even though drinking whey protein makes more building-block amino acids show up in the blood during extreme dieting, those amino acids don’t get the muscle to grow like they normally would.