Eggs for Muscle Growth: Whole Egg or Just Egg White?

Geschatte leestijd: 4 minutenEggs for muscle growth, do you eat only the egg white or the whole egg? There is a big difference in the way muscle mass is built when you get 18 grams of protein from a whole egg or just from the egg white after a workout. The so-called protein synthesis is 40% greater when the whole egg is used, according to recent research.

Eggs for Muscle Growth: Whole Egg or Just Egg White?

You can have endless discussions about the advantages or disadvantages of egg yolk. Depending on the time period, you should limit, avoid, or welcome egg yolk. People who want to use the protein in eggs for muscle growth sometimes play it safe by using only the egg white. For example, you might be concerned about the cholesterol in the egg yolk, although that is probably unfounded. You might also want to avoid the fats because of the extra calories. However, you will miss out on the protein in the egg yolk, but you can replace it with extra protein.

Bottles containing only egg whites are increasingly available. I once wrote about the search for such bottles inspired by Ronnie Coleman’s ‘grits’ and the advantage of these liquid proteins. At first, I only found them at the wholesale store, which was not practical given the expiration date and the size of the bottles. Later, Body & Fitshop offered them in more convenient packaging, making them more practical. Last weekend, I found the same bottles in my local supermarket. This turned out to be handy for the hazelnut chocolate fudge cinnamon meringues I made for the holidays.

Just when it couldn’t be easier to eat protein without being left with the egg yolk, you seem to be missing out on extra muscle mass gains. Recent research from the University of Illinois shows that eating 18 grams of protein leads to a 40% higher protein synthesis when it comes from the whole egg instead of just the egg white. Protein synthesis is the creation of protein in the muscles from the available amino acids in the blood obtained from protein in food. The research was published in the American Journal of Clinical Nutrition. The other substances in the egg yolk somehow help the muscles to utilize the protein better, although it is not clear why.

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.

Nicholas Burd, University of Illinois

In the study, 10 young and trained men participated in a single strength training session. Then they ate either whole eggs or only egg whites, both providing 18 grams of protein. By ‘labeling’ two amino acids (leucine and phenylalanine) in both sources with an isotope, they could determine the extent to which these ended up in the blood and muscles. They took measurements before, during, and after the training.

More Muscle Growth with Whole Eggs

With these measurements, they found that in both cases, the same amount of amino acids ended up in the blood, about 60 to 70 percent. Since the availability of amino acids in the blood is normally a key indicator of the extent of muscle growth, you would think that it doesn’t make a difference.

However, when they looked at muscle protein synthesis in the muscles themselves, they saw a big difference in response.

We saw that the ingestion of whole eggs immediately after resistance exercise resulted in greater muscle-protein synthesis than the ingestion of egg whites.

If you get the same amount of protein from whole eggs as from egg whites, it automatically means that you get more calories/energy. After all, you also get the fats, about 17 grams for every 18 grams of protein. Fats also provide more than twice as many calories, making those 17 grams of fat good for 153 kcal. Extra energy can save the need to break down protein in the muscles. After all, muscle mass is the result of the continuous production (anabolism) and breakdown (catabolism) of protein in the muscles. However, their research shows that this saving effect did not occur when eating whole eggs. The researchers also refer in this context to previous studies showing that adding an extra energy source such as carbohydrates or fats does not increase the anabolic response to protein.

It is therefore not clear what the cause is of the higher protein synthesis when eating the whole egg. The researchers take into account anabolic properties of other substances in egg yolk such as microRNAs, vitamins and minerals, and the omega-3 fatty acid DHA.

It seems in any case not useful to remove the egg yolk when the extra calories are not a problem for your total intake for the day. Even if that is the case, you may wonder if you shouldn’t save those calories better in another meal. Based on this research at least. Given the size of the study, it would be nice if a larger follow-up study confirms these results.

Reference

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