Nutritional Values of the Egg

        Eggs are an important source of protein, essential vitamins and minerals and can make a significant contribution to a healthy diet. Nutritional requirements can vary considerably between men, women and children and can also vary in individuals from time to time.

To illustrate the contribution that eggs make to the diet and nutritional requirements, please refer to the table below. The data on the nutritional content of a single egg is based on a medium egg and all percentage composition figures relate to the contents, excluding the shell.

Source: Royal Society of Chemistry/ Food Standards Agency 2002 The Composition of Foods (6th edition)

Nutritional analysis of egg without its shell For a medium egg (Av 58g)
Constituent of Egg Amount per egg % of Reference Nutrient Intake (RNI) Amount per 100g egg
For adult female 19-50 years For adult male19-50 years

Weight 1

51.6

-

-

100.0

Water

g

38.8

-

-

75.1

Energy

kjoules/ kcalories

324/78

4

3

627/151

Protein

g

6.5

14

12

12.5

Carbohydrate

g

trace

-

-

trace
Fat

g

5.8

**

**

11.2

Inc saturated f.a.

g

1.7

**

**

3.2

Monounsaturated f.a

g

2.3

**

**

4.4

Polyunsaturated f.a.

g

0.9

**

**

1.7

Dietary fibre

g

none

-

-

none

MINERALS AND TRACE ELEMENTS

Sodium

mg

72

4.5

4.5

140

Potassium

mg

67

3

3

130

Calcium

mg

29

4

4

57

Phosphorus

mg

103

19

19

200

Magnesium

mg

6.2

2

2

12

Iron

mg

1.0

7

11 1.9

Zinc

mg

0.7

10

7 1.3

Copper

mg

0.04

3

3

0.08

Iodine

m g

27

19

19

53

Chlorine

mg

83

3

3

160

Sulphur

mg

93

*

*

180

Selenium

m g

6

10 8 11

VITAMINS

Vitamin A m g

98

16

14

190

Vitamin D

m g

0.9

9***

9***

1.8

Vitamin E

mg

0.57

*

*

1.11

Vitamin C

mg

none

-

-

none

Thiamin (B 1 )

mg

0.05

6

5

0.09

Riboflavin (B 2 )

mg

0.24

22

18

0.47

Niacin

mg

0.05

15

11

0.1

Vitamin B 6

mg

0.06

5

4

0.12
Folate m g

26

13

13

50

Vitamin B 12

m g

1.3

87

87

2.5
Biotin m g

10

*

*

20

Pantothenic acid

m g

0.91

*

*

1.77

1 Assumes edible portion = 89%
*No RNI  **No RNI, for recommendations on fat  ***Beyond age 65 years

Energy value of eggs

A medium egg has an energy value of 78 kilocalories (324 kilojoules) and the consumption of one egg daily would contribute only around 3% of the average energy requirement of an adult man; 4% for an adult woman.

With their significant protein, vitamin and mineral content and relatively low saturated fat content, eggs are a valuable component in a healthy diet.

Protein

Eggs are an excellent source of protein. Egg protein is of high biological value as it contains all the essential amino acids needed by the human body. Eggs therefore complement other food proteins of lower biological value by providing the amino acids that are in short supply in those foods. 12.5% of the weight of the egg is protein and it is found in both the yolk and the albumen. Although protein is more concentrated around the yolk, there is in fact more protein in the albumen.

On the evaluation scale most commonly used for assessing protein, egg is at the highest point, 100, and is used as the reference standard against which all other foods are assessed.

Vitamins

Eggs contain most of the recognised vitamins with the exception of vitamin C. The egg is a good source of all the B vitamins, plus the fat-soluble vitamin A. It also provides useful amounts of vitamin D, as well as some vitamin E.

Minerals

Eggs contain most of the minerals that the human body requires for health. In particular eggs are an excellent source of iodine, required to make the thyroid hormone, and phosphorus, required for bone health. The egg provides significant amounts of zinc, important for wound healing, growth and fighting infection; selenium, an important antioxidant; and calcium, needed for bone and growth structure and nervous function. Eggs also contain significant amounts of iron, the vital ingredient of red blood cells, but the availability of this iron to the body is uncertain.

Carbohydrate and dietary fibre
Eggs contain only traces of carbohydrate and no dietary fibre.

Fat

11.2% of the egg content is fat. The fat of an egg is found almost entirely in the yolk; there is less than 0.05% in the albumen.

Approximately 17% of an egg's fatty acids are polyunsaturated, 44% monounsaturated and only 32% saturated.

Cholesterol

Cholesterol and Lecithin are fat-like substances and are essential to the structure and function of all cells in the body. Cholesterol helps to maintain the flexibility and permeability of cell membranes and is also a raw material for the fatty lubricants that help to keep the skin supple. Cholesterol is essential for the production of sex hormones, cortisol, vitamin D and bile salts.

Lecithin is involved in general lipid transportation in the blood and in the metabolism of cholesterol.