Is there any advantage to making your omelet with only egg whites, and not the whole egg? It does seem like a popular enough option at most diners, so there must be something to it. But how much is legitimate nutrition science, and how much is just a marketer’s attempt to make you feel better about paying more for the same thing?
Of course, sheer mathematics dictates that egg whites have less of anything that an egg has: less protein, less calories, less fat, fewer nutrients. In fact, egg whites are 90 percent water. The other 10 percent is all protein, however, and that has made them a go-to food for bodybuilders who have high protein requirements but need to watch their calorie intake.
The protein in the egg white is particularly choice, as well. It is complete, which means it possesses all nine essential amino acids in the optimal amounts that your body requires.
Unfortunately, egg yolks have a lot going for them. Those people, bodybuilders and otherwise, who shun the yolks are missing out on two important antioxidants, lutein and zeaxanthin. Both of these are valuable assets in older folks’ battles against eye degeneration and cataracts. And you don’t have to be older to appreciate the choline that egg yolks add to your diet. It’s a B vitamin and crucial nutrient that aids in intracellular communication and keeps your liver healthy, at all ages.
Egg yolks, with their high levels of cholesterol, have gotten a bad rap since the infamous flawed research of the Seven Countries’ Study. But now we know that, for most people, cholesterol in eggs is no problem at all.
There is, however, a slight but hidden danger to eating only egg whites in lieu of whole eggs. Raw egg whites diminish the absorption of biotin, a B vitamin necessary for the production of fatty acids, the metabolism of fats and amino acids, and cellular growth in general. Egg whites, unaccompanied by the yolks, contain a protein called avidin, which can bind to biotin and prevent it from being absorbed. Fortunately, you would have to eat an awful lot of egg whites to inhibit biotin absorption to the degree it would have a meaningful effect upon your health.
When all is said and done, there are few concrete benefits to eating egg whites alone. The calories are fewer, but whole eggs provide you with many more nutrients than just the whites alone.