|
The egg is a nutrient-dense food, containing high quality protein and a wide range of essential vitamins, minerals and trace elements. Therefore eggs can make a significant contribution to a healthy diet. Nutritional requirements vary considerably between men, women and children and can also vary in individuals from time to time.
The nutritional value of eggs and the contribution that they make to the diet is illustrated by the following table. 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: FSA (Food Standards Agency) (2002) McCance and Widdowson’s The Composition of Foods, Sixth summary edition. Cambridge: Royal Society of Chemistry
| 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 |
|
Weight1
|
|
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 |
|
Cholesterol
|
mg
|
202
|
** |
** |
391
|
|
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
|
mg
|
27
|
19
|
19
|
53 |
|
Selenium
|
mg
|
6
|
10 |
8 |
11 |
|
Chlorine
|
mg
|
83
|
3
|
3
|
160 |
|
Sulphur
|
mg
|
93
|
*
|
*
|
180 |
|
VITAMINS
|
|
| Vitamin A |
mg |
98
|
16
|
14
|
190 |
|
Vitamin D
|
mg |
0.9
|
9***
|
9***
|
1.8 |
|
Vitamin E
|
mg |
0.57
|
*
|
*
|
1.11 |
|
Vitamin C
|
mg |
none
|
-
|
-
|
none |
|
Thiamin (B1)
|
mg |
0.05
|
6
|
5
|
0.09 |
|
Riboflavin (B2)
|
mg |
0.24
|
22
|
18
|
0.47 |
|
Niacin
|
mg |
0.05
|
15
|
11
|
0.1 |
|
Vitamin B6
|
mg |
0.06
|
5
|
4
|
0.12 |
| Folate |
mg |
26
|
13
|
13
|
50 |
|
Vitamin B12
|
mg |
1.3
|
87
|
87
|
2.5 |
| Biotin |
mg |
10
|
*
|
*
|
20 |
|
Pantothenic acid
|
mg |
0.91
|
*
|
*
|
1.77 |
1Assumes 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 source of all the B vitamins. It is a particularly rich source of vitamins B12 and B2 (riboflavin) and a useful source of folate. The egg is also a good source of the fat-soluble vitamins A and D and provides some vitamin E.
Minerals
Eggs contain many 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 is a significant source of selenium, an important antioxidant and provides some zinc, important for wound healing, growth and fighting infection. Eggs also contain iron, the vital ingredient of red blood cells, although the availability of this iron to the body is still being investigated.
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
Eggs also contain cholesterol and lecithin, which are fat-like substances that are essential to the structure and function of all cells in the body. However these substances are not dietary essentials, as our bodies are able to synthesise them. 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.
For more information on Cholesterol click here
|
