At just 78 calories, a large egg is a good source of several essential nutrients. Boiling is an easy, fat--free cooking technique and the finished product can be added to salads or consumed as a convenient snack. According to the Federal Food Safety website, eggs should be boiled until both the white and yolk are firm, about 10 minutes.
Protein
According to the USDA nutrient database, one large egg contains 6g protein, 13 percent of the recommended daily value (DV) for adults. The protein is found in both the white and the yolk and is of very high quality, containing all of the essential amino acids---protein building blocks---in similar ratios to that found in the human body. Protein is found in every cell. In addition to providing energy, it helps to build and repair body tissue and aids in immune function.
Fats and Cholesterol
A large egg contains 5g total fat; the fat is in the egg yolk. Of this, 1.6g is saturated fat---the type that can contribute to raising LDL, or "bad", cholesterol. There are 2g monounsaturated and 0.7g polyunsaturated fat, which do not raise LDL cholesterol. The egg yolk also contains 186mg cholesterol. If you have heart disease or a high risk blood cholesterol level, the American Heart Association recommends limiting egg yolks to two per week due to their high dietary cholesterol content. An egg is low in sodium, with just 62mg.
Choline
A large egg also provides 23 percent of the DV for choline. Grouped with the B vitamins, choline is important for normal functioning of cells, metabolism, brain and nerve function, memory and the transport of nutrients throughout the body. According to the August 2010 "Journal of the American Dietetic Association," it is especially important for pregnant and lactating women to get sufficient choline. It helps prevent birth defects and promotes brain and memory development in infants.
Selenium
Selenium is a trace mineral, essential in very small amounts. According to the NIH's Office of Dietary Supplements, selenium is incorporated into proteins to make antioxidant enzymes that help prevent cellular damage from free radicals. They also help regulate thyroid function and aid immune function. A large egg provides 27 percent of the DV for selenium.
Riboflavin
An egg is a good source of riboflavin. Another B vitamin, riboflavin helps the body release energy from protein, fat and carbohydrate during metabolism. A large egg contains 15 percent of the DV for riboflavin.
Vitamin B12
Providing 11 percent of the recommended DV, an egg is also a good source of vitamin B12. Since B12 is found only in animal products, eggs can be an important source for lacto-ovo vegetarians. It has several important functions in the body---it aids in forming red blood cells, building genetic material, nervous system function and fat and protein metabolism. Along with folate and vitamin B6 it may improve heart health, according to the American Dietetic Association.
Phosphorus
Phosphorus is a mineral that helps build strong bones and teeth. It is involved in the release of energy from fat, protein and carbohydrate during metabolism. It also aids in the formation of genetic material, cell membranes and many enzymes. A large egg is a good source of phosphorus, providing 10 percent of the DV.
References
- FoodSafety.gov: Eggs and Egg Products
- USDA National Nutrient Database for Standard Reference
- Incredible! Egg: Egg Nutrients
- NIH: Lowering Your Cholesterol with TLC
- "Journal of the American Dietetic Association"; Pre- and Post-Natal Health: Evidence of Increased Choline Requirement; August, 2010.
- American Dietetic Association Foundation: "B" Smart for Your Heart and Pregnancy with Folic Acid and Vitamins B6 and B12; 2000.
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