Want to get jacked?
Don’t lose the yolk.
That’s the takeaway from a new study from the University of Illinois at Urbana-Champaign that found post-workout muscle-building response to be 40 percent greater in athletes who ate whole eggs than it was in athletes who ate an equivalent amount of protein via egg whites.
In the past, many fitness fanatics have avoided the egg yolk as a way to spare themselves from additional calories and fat. And since the egg white contains the majority of the protein inside eggs, there seemed to be little downside with prioritizing their consumption. However, this finding flips that rationale on its head. From ScienceDaily:
The discovery, reported in the American Journal of Clinical Nutrition, suggests that the widespread practice of throwing away egg yolks to maximize one’s dietary protein intake from eggs is counterproductive, said Nicholas Burd, a University of Illinois professor of kinesiology and community health who led the research.
The study consisted of 10 young men who engaged in a single bout of resistance training and then immediately consumed 18 grams of protein via whole eggs or egg whites. The eggs utilized in the study were specially designed so researchers could track where “food-derived amino acids ended up after participants ingested them.”
When we digest the protein found in food, it is broken down into specific amino acids, which are then selectively reassembled into proteins once again. Most of the solid matter in our bodies—bones, muscles, organs and skin—is made up of these proteins. That’s why protein—and thus, amino acids—are incredibly important for muscle-building and recovery.
Researchers found that both whole eggs and egg whites led to 60-70 percent of their amino acid content being available in the blood to create new muscle. However, when they directly examined protein synthesis in the muscle, they saw that the whole eggs led to a significantly greater response. This directly translates to enhanced muscle building.
“We saw that the ingestion of whole eggs immediately after resistance exercise resulted in greater muscle-protein synthesis than the ingestion of egg whites,” Burd said. “This study suggests that eating protein within its most natural food matrix tends to be more beneficial to our muscles as opposed to getting one’s protein from isolated protein sources.”
Researchers deduced that there must be something in the yolks “boosting the body’s ability to utilize (protein) in the muscles.”
According to Harvard Medical School, many of “the health effects of food likely derive from the synergistic interactions of nutrients and other compounds within and among the foods we eat.” That means that many of the nutrients in whole foods interact in a meaningful, beneficial way, which supplements simply can’t replicate. This isn’t to say that egg whites are a supplement, but the same idea still applies. By excising the yolk, you may be eliminating a natural combination of nutrients which work in concert to build muscle more effectively.