How Many Calories in an Egg and Are Eggs Healthy?

When determining how many calories in an egg you should not only calculate the entire calorie total, but also consider the nutrient density of the different components of the egg such as just the egg whites and the egg yolks. According to the USDA National Nutritional Database (1), a whole large chicken egg contains 6.28 grams of protein and 72 calories. That means that the protein in an egg accounts for approximately 35% of its total calories.

In order to get an equivalent amount of protein (3) from other sources, you would need to eat, for instance, two ounces of equivalent protein foods. Taking this further, the amount of protein that you intake when you consume a small chicken breast is similar to 3 ounce serving (4) of equivalent protein based upon the USDA’s dietary guidelines. The USDA dietary guidelines say that the average adult needs between 5 and 6 servings (remember, a serving is equal to an ounce or the equivalent of an ounce) of protein per day. One egg, therefore, gives you about one fifth of your totally daily dietary protein requirement. So does an egg a day keep the doctor away? Not so fast.

While eggs are rich in protein and are, therefore, excellent sources of protein, we need to take a closer look at the nutritional breakdown of an average egg in order to understand how healthy an egg is and how many eggs we should really be eating instead of just being focused on how many calories in an egg.

While a whole egg contain about 6 grams of protein, the bulk of the protein in an egg comes from the egg white. One large egg white contains 3.6 grams of protein and just 17 calories. This means that the majority of the protein in an egg (57%) comes from the egg white. This also means that egg whites are more nutrient dense than a whole egg. So, what do we mean by nutrient dense? Nutrient density (2) refers to the amount of nutritional benefit you get per calorie. That is, a nutrient dense food provides you with the health benefits associated with a particular nutrient but does so with relatively few calories. Two egg whites provide more protein (7.2 grams vs. 6.28 grams) than a whole egg but do so with almost half as many calories (34 vs. 72).

Obviously, choosing egg whites over the whole egg is a good option for anyone looking to cut down on their overall caloric intake or anyone trying to lose weight. But, there is another benefit to choosing egg whites over a whole egg. In addition to providing less protein than the egg white, the egg yolk provides more saturated fat. There is 1.6 gram of saturated fat in an egg yolk compared to an egg white, which has no saturated fat. So, should we be giving up egg yolks altogether? Not at all. Though they contain saturated fat, egg yolks also contain polyunsaturated (.7 gram) and monounsaturated (1.9 grams) fats (5).  These so-called “good fats” improve our cognitive function, prevent cardiovascular disease and help with inflammatory conditions such as arthritis and diseases such as asthma and Crohn’s disease. A good option is to eat one egg plus two whites instead of eating two eggs. In this way, you are getting all of the nutritional benefits but with fewer calories and less saturated fat.