The Food We Eat

The energy value of food is measured in calories - units of heat. A man lying in bed all day would need about 1700 calories a day to prevent him from losing weight. If he got up and did an hour or so of light work, like typing, he would need about another 75 calories. An hour's walking would add another 150 and an hour's hard work like digging the garden, would mean another 300 or so. Needs vary with the weight of the body, but the whole the amount of food needed depends on the work done.

Modern nutritional science has made it possible, therefore, to design standard diets for miners, office-workers, housewives and schoolchildren. This means, for example that in war-time food be shared out fairly and efficiently. In peace-time it enables people to judge their food requirements accurately in the interests if their health.

No less important that the quantity of food we eat is its quality.Everyone needs an adequate and balanced diet to help them keep warm and fight off disease, and children in particular need good food to allow them and to grow up strong and healthy. There are three main categories of foodstuffs;carbohydrates (starch and sugar), protein (meat fish, dairy products), fats (especially butter and other substances required such as calcium, minerals and vitamins)