How many calories in an egg?
We eat around 12.5 billion eggs in the UK each year.
Eggs are nutritious and contain protein, vitamins and minerals.
In the UK, eggs are graded into four sizes: small (under 53g weight), medium (53-63g), large (63-73g) and extra large (74g and above). A medium egg has around 66 calories and a large egg around 80 calories.
An average egg, minus its shell, is 12.6% protein by weight with slightly more protein found in the white albumen than the yellow yolk.
Eggs contain negligible amounts of carbohydrate.
Around 9% of an egg is fat, found mainly in the yolk. Fat in eggs is mainly the healthier monounsaturated fat, around a quarter is saturated fat and the remainder polyunsaturated fat. Eggs are also a good source of omega-3 fatty acids as DHA (docosahexaenoic acid), which can be helpful for people who don't eat fish. Some eggs are now sold with an enriched content of omega-3s.
Eggs are a good source of B vitamins (especially B12 and riboflavin), and vitamin D. They’re also a useful source of vitamin A, folate, pantothenic acid, biotin and choline.
When it comes to minerals, eggs contain iodine needed for thyroid health, the antioxidant selenium, phosphorus for bone health, and some zinc.
Egg yolk is also a good source of the naturally occurring carotenoids, lutein and zeaxanthin. These substances are found in high concentration in the eye, and are known to protect the eye against UV light damage.
Eggs and cholesterol
Eggs naturally contain cholesterol, with a medium egg providing around 177mg cholesterol. In the early days of heart disease research, it was thought that dietary cholesterol was the main reason for a high blood cholesterol – which we now know not to be true. Cholesterol is made by our body, and if we take cholesterol in foods like eggs, we produce less of it ourselves.
The British Heart Foundation says it is a myth that eggs are bad for the heart. But for a healthier way of eating, boil, poach or scramble eggs rather than frying them.
In many parts of the world, salmonella in eggs is a concern, as it was in the UK until the late 1990s. However, the ‘Red Lion’ accreditation mark on British eggs means hens have been vaccinated against salmonella and kept in conditions that meet stringent food safety standards.
Some people and babies at a higher risk of infection may be advised not to eat undercooked (runny) eggs.
The sell-by date for eggs is the last date shops should display them for sale.
The best-before date is the period in which eggs keep their best quality, texture and flavour.
European food safety officials say keeping eggs refrigerated is the only way to reduce the increased risk of infections due to extended storage.
Thorough cooking, such as hard-boiling or baking, also reduces the risk.
Allergies to eggs, products cooked using eggs and vaccines made using eggs, are common food allergies.
Allergy to eggs is more common in young children than it is for adults. However, most children will eventually outgrow an egg allergy.
Go to work on an egg?
The old advert urging us to 'Go to work on an egg' may have been right. Starting your day off with an egg may help curb your appetite better than cereal, research has suggested. In a small study in 2012, it took longer for people who ate eggs for breakfast to feel hungry than it did for those who had a bowl of ready-to-eat cereal.
Dietitian reviewed by Catherine Collins RD