How Much Protein Does One Egg Yolk Contain?

Raw egg in bowl
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Eggs provide a nutrient-rich source of easy-to-digest, high-quality protein, according to the University of Kentucky. The egg white and yolk have almost an equal amount of protein, while yolks are a significantly higher source of vitamins and minerals than the egg whites. Provided you don't have problems with your cholesterol, eggs are a healthy source of protein that can help you stay energized and maintain a feeling of fullness.

Value of Protein

Your body is composed of at least 10,000 different types of protein, according to the Harvard School of Public Health. Protein is found in virtually every cell in your body. It provides structure, forms enzymes and hormones, and is essential for muscles to function. When you eat protein, it's digested into amino acids. Then your body uses the amino acids to rebuild the specific protein it needs. If even one amino acid is not available, that protein can't be produced. Since your body does not store amino acids, you need to consume sufficient protein daily to support optimal health.

Types of Protein

Nine of the amino acids needed for protein synthesis must come through your diet because your body can't make them. Foods that contain a sufficient amount of all nine amino acids are called complete, or quality, proteins. Animal sources of foods, including eggs, are complete proteins. While a few plant-based foods, such as soybeans and quinoa, contain complete protein, most foods from plants are incomplete proteins. Incomplete proteins usually contain all nine amino acids, but they have too little of one or more amino acid.

About 10 to 35 percent of your daily calories should come from protein, according to the Institute of Medicine. This range represents the least amount needed to support your health, while the upper end is based on ensuring your daily diet doesn't include so much protein that it excludes essential carbs and fats. The IOM also defines a recommended daily allowance. The RDA for women is 46 grams, while men should consume 56 grams of protein daily.

Protein in Egg Yolks

The yolk from one large egg contains 2.7 grams of protein. By comparison, the white from the same-sized egg has 3.6 grams of protein. The yolk contains a significant majority of many of the whole egg's nutrients, including calcium, iron, folate, and vitamins B-12 and A. It also contains all of the egg's fat. You'll get 4.5 grams of total fat, 1.6 grams of saturated fat and 184 milligrams of cholesterol from eating one egg yolk.

Dietary Cholesterol

The cholesterol in one egg yolk represents 61 percent of the total cholesterol you should consume in a day. However, the cholesterol you get through your diet has a small impact on blood levels of cholesterol. If you're healthy, eating up to one whole egg daily does not increase your risk of heart disease, according to the Harvard School of Public Health. This advice does not apply to people who already have high cholesterol or have been diagnosed with cardiovascular disease or diabetes. If you have any health concerns, you should limit egg consumption to no more than three yolks per week, or follow your doctor's instructions.