Are Hard-Boiled Egg Whites as Healthy as the Whole Egg?

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Every large hard-boiled egg, which is about 50 grams (1.76 ounces), contains about 78 calories and a variety of nutrients. Hard-boiled egg nutrition facts for one large egg include:

• 8 percent of the daily value (DV) for vitamin A
• 20 percent of the DV for riboflavin (vitamin B2)
• 14 percent of the DV for pantothenic acid (vitamin B5)
• 6 percent of the DV for folate (vitamin B9)
• 23 percent of the DV for vitamin B12
• 6 percent of the DV for vitamin D
• 7 percent of the DV for phosphorus
• 28 percent of the DV for selenium
• 5 percent of the DV for zinc
• 27 percent of the DV for choline

There are 5.3 grams of fat (8 percent of the DV), 6.3 grams of protein (13 percent of the DV) and no carbs contained in hard-boiled eggs. They're also good sources of nutrients such as lutein, zeaxanthin and omega fatty acids.

Hard-boiled eggs have small amounts of B-complex vitamins and vitamin E as well. Furthermore, they have small amounts of minerals such as calcium, copper, iron, magnesium, manganese and potassium. Each large egg also contains 186.5 milligrams of cholesterol.

Hard-boiled eggs are cooked in water, without any added fats. This makes them one of the healthiest ways you can eat your eggs, and it also means that very few nutrients change during the cooking process. In fact, hard-boiled eggs are almost identical in nutrient content to raw eggs.

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In comparison to the nutrition supplied by a whole hard-boiled egg, egg whites are fairly low in nutrients. In one large egg white, you can find:

• 7 percent of the DV for protein
• 12 percent of the DV for selenium
• 11 percent of the DV for riboflavin (vitamin B2)

Egg whites also have small amounts (between 1 and 4 percent) of B-complex vitamins, potassium, magnesium and copper. One large egg white's calories total just 17 — compared to 78 in a whole, large egg.

However, egg whites lack the vast majority of the nutrients found in the whole egg. This means they contain no vitamins A, D or E and no calcium, iron, manganese, phosphorus or zinc. They also have no choline, lutein or zeaxanthin. The upside is that, unlike whole eggs, egg whites have no fat or cholesterol.

Although fresh hard-boiled egg whites are low in nutrients, according to a 2014 study in the Journal of Poultry Science, you can preserve egg whites through pickling to enrich their nutrient content. Pickling duck egg whites has been shown to increase their amounts of essential amino acids and minerals like calcium, copper, iron, magnesium, potassium and zinc.

From a nutritional perspective, it may seem that you are getting the short end of the stick if you're eating only the egg white rather than the whole hard-boiled egg. However, although egg whites are low in nutrients, they're still a good source of protein, and in fact, the proteins in egg whites are rich in antioxidants.

Antioxidants are found primarily in boiled egg whites. A 2014 study in the Journal of Biochemical and Biophysical Research Communications and a 2015 study in the Journal of Food Chemistry identified egg whites as being rich in antioxidant peptides.

These antioxidants can be found in various types of egg whites — not just chicken egg whites, but those of other birds too. Antioxidants are important, as they may be able to help prevent a variety of different diseases and improve overall health.

Egg whites also have no cholesterol — all of the egg's cholesterol is in the yolk. The Dietary Guidelines for Americans no longer limits the amount of cholesterol you should consume on a daily basis, as dietary cholesterol is unlikely to increase the cholesterol levels in your blood. However, people who are sensitive to cholesterol and those who have certain medical conditions may still need to watch their cholesterol consumption.

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If you're eating hard-boiled egg whites, you're likely going to have to boil the whole egg until it's fully cooked and then remove the yolk. The amount of egg white you end up with is obviously based on the amount of yolk you remove and the type of egg you have.

In a chicken egg, 58 percent is egg white, 31 percent is egg yolk and the remainder is eggshell. This means that in an average large egg (55 grams or 1.76 ounces), you will have about 6 percent shell, 32 percent egg white and 17 percent egg yolk. However, the actual amount of egg white you have can be determined based on various factors, such as:

• The type of bird: As you might imagine, quails, chickens and duck eggs don't have the same yolk-to-white ratio. In fact, duck eggs are known for having a larger ratio of egg yolk to egg white, while quails eggs have a smaller ratio. Even the breed of bird within species can cause variations in yolk-to-white ratios.

• Age: How old the bird is can also play a role in the yolk-to-white ratio.

• Egg size: This is not only based on species-specific factors (like the difference between a quail egg and a duck egg) but among standard eggs within a species. The United States Department of Agriculture states that chicken eggs sold in the United States can range between 1.25 ounces (35.5 grams) and 2.42 ounces (about 68.5 grams). These are known as peewee and jumbo eggs, respectively.