A single large egg (about 50 grams) packs 77 calories, 6.3 grams of protein, 5.3 grams of fat, and barely any carbohydrate (under 1 gram). That compact package also delivers a surprisingly wide range of vitamins, minerals, and other compounds that make eggs one of the most nutrient-dense foods you can eat. Here’s what’s actually inside.
Protein and Why Egg Protein Stands Out
The 6.3 grams of protein in a large egg might not sound like much, but what matters is the quality. Egg protein contains all nine essential amino acids your body can’t make on its own, and it scores higher than nearly any other whole food on the standard scale scientists use to rate protein quality. On that scale (called PDCAAS), egg protein scores 118 out of a possible 100, meaning it delivers more usable amino acids per gram than the benchmark requires. Its digestibility rate sits at 98%, which is about as high as protein absorption gets.
One important caveat: cooking matters. Your body absorbs roughly 91% of the protein in a cooked egg, compared to only about 51% from a raw egg. Heat unfolds the protein molecules, making them far easier for your digestive system to break down. So drinking raw eggs, Rocky-style, actually wastes nearly half the protein.
More than half the egg’s total protein lives in the white. The yolk contains the rest, along with nearly all the fat and most of the vitamins.
Fat Breakdown
A large egg contains about 5.3 grams of total fat, all of it in the yolk. That fat breaks down into three main types. Roughly 37 to 40% is saturated fat (about 1.6 grams per egg), 43 to 53% is monounsaturated fat (the same heart-friendly type found in olive oil), and 12 to 16% is polyunsaturated fat, which includes small amounts of omega-3 fatty acids. The fat profile is more balanced than most people assume. The monounsaturated portion actually makes up the largest share.
Cholesterol: What the Guidelines Say Now
A large egg contains about 186 milligrams of cholesterol, all in the yolk. For years, that number scared people away from eggs. The science has shifted considerably. The American Heart Association’s 2026 dietary guidance states that dietary cholesterol is “no longer a primary target” for heart disease risk reduction for most people. Moderate egg consumption can be part of a heart-healthy diet. The bigger concern, the AHA notes, is the company eggs tend to keep: processed meats like bacon and sausage that often share the plate.
Vitamins Packed Into the Yolk
The yolk is where the micronutrient action is. Every bit of the egg’s vitamin A, vitamin D, vitamin E, and vitamin K lives in the yolk. One egg provides about 10% of your daily vitamin D needs (41 IU), which is notable since very few foods are natural sources of vitamin D at all. The yolk also holds higher concentrations of B6, B12, folic acid, and pantothenic acid compared to the white.
The white isn’t nutritionally empty, though. It contributes most of the egg’s niacin and riboflavin (two B vitamins involved in energy metabolism), along with the majority of the egg’s magnesium, potassium, and sodium.
Minerals and Other Compounds
Beyond the headline nutrients, eggs supply meaningful amounts of selenium, phosphorus, iron, zinc, and calcium, with the yolk again carrying the larger share of each. The yolk also contains choline, a nutrient many people don’t get enough of. Choline plays a key role in brain function and cell membrane integrity, and eggs are one of the richest dietary sources.
Two lesser-known compounds in the yolk are lutein and zeaxanthin, pigments that give the yolk its yellow color. A typical egg yolk contains about 143 micrograms of lutein and 94 micrograms of zeaxanthin. These pigments accumulate in the retina and help protect your eyes from damage caused by blue light and oxidative stress. Because the yolk’s fat helps your body absorb these pigments efficiently, eggs are a particularly effective way to get them compared to supplements or vegetables.
Yolk vs. White at a Glance
- Yolk: All the fat, cholesterol, vitamin A, D, E, and K. Most of the B vitamins (except niacin and riboflavin). More calcium, iron, selenium, zinc, and phosphorus. All the choline, lutein, and zeaxanthin.
- White: More than half the protein. Most of the niacin, riboflavin, magnesium, potassium, and sodium. Zero fat.
If you’re eating only egg whites to cut calories or fat, you’re getting good protein but leaving most of the egg’s nutritional value behind.
Egg Sizes and What Changes
Most nutrition labels reference a “large” egg, which must weigh at least 2 ounces (about 57 grams including the shell). Medium eggs clock in at a minimum of 1.75 ounces per egg, while extra-large eggs start at 2.25 ounces. The nutrient content scales proportionally, so an extra-large egg will have noticeably more protein and fat than a medium one. If a recipe or nutrition plan specifies “one large egg,” swapping in a different size will shift the numbers.
Food Safety and Salmonella
The main safety concern with raw or undercooked eggs is Salmonella Enteritidis, a bacterium that can cause food poisoning. The actual contamination rate is very low. Large-scale studies estimate that roughly 0.03% of commercial eggs (about 1 in 3,000 to 1 in 10,000) carry the bacterium. An infected hen produces approximately one contaminated egg out of every 200 she lays. Cooking eggs to the point where both the white and yolk are firm kills Salmonella reliably, which is another practical reason cooked eggs beat raw ones: better protein absorption and virtually no infection risk.