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December 7, 2021 • Fitness

Protein at Breakfast Key for Muscle Growth & Function

Want to optimize your muscle health? Be sure to include a robust dose of protein early in the day. In a new study that is getting lots of buzz and adds to the exciting new science of “chrono-nutrition” (how food timing impacts health and function in various organs of the body), scientists determined that when we eat our protein really matters. It seems consuming protein early in the day is significantly more effective at boosting muscle growth and function than protein consumed later in the day. 

What’s more, the scientists found this to be the case in both mice and humans. For this study, scientists began by feeding lab mice two test meals a day – one high in protein and one low in protein. Measure for measure, protein consumed at breakfast was significantly more effective at boosting muscle growth relative to protein consumed at dinner. Specifically, mice experienced 17% more muscle hypertrophy after the low protein breakfast vs. after the high protein dinner. 

Meaning, even a smaller dose of protein at breakfast was more effective at stimulating an increase in muscle size than a larger dose at dinner! The scientists conducted additional experiments that uncovered the basis of their findings – the all-powerful 24-hour circadian rhythm. The circadian rhythm is the 24-clock inherent in all living cells that dictates their function moment to moment. It is now well documented that what is happening in a particular cell type in the morning, in this case, muscle cells, can be widely divergent than what happens in the same cells in the evening. 

To further investigate these findings in humans, the scientists conducted a similar experiment with sixty elderly women. Once again, they noted that protein consumed at breakfast was superior to protein consumed at dinner for enhancing muscle strength. These findings are notable on two key fronts. One, maintaining optimal muscle strength and mass is fundamental to functionality, weight control, cardiometabolic health, and even cognitive health. And two, the average adult consumes a meager 15 grams of protein at breakfast relative to 28 grams at dinner! 

Based on the data available at this juncture, we would all be wise to include our largest dose of daily protein before 10 am – meaning shift some of your dinner protein to breakfast. I sure am. 


Cell Reports, 2021; 36 (1): 109336 DOI: 10.1016/j.celrep.2021.109336