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Energy for work and play

Energy: nothing works without it

Energy from food is what keeps us alive and active. Energy is required for even the smallest of movements. Even when sleeping, our bodies still need energy so that our metabolism, heart and breathing function and our body temperature is maintained.

Energy Supply

Our bodies’ main sources of energy are carbohydrates and fats. We can also use protein and alcohol as sources of energy. The energy content of food is measured in kilocalories (kcal) or kilojoules (kJ). One kilocalorie is equivalent to 4.2 kilojoules. Not all types of food contain the same amount of energy. Of all of the food types, fat provides the most energy. Alcohol is also very high in energy. Carbohydrates and protein, on the other hand, have half as many kilocalories:

  • 1 gram of fat provides approx. 9 kcal
  • 1 gram of alcohol provides approx. 7 kcal
  • 1 gram of carbohydrate provides approx. 4 kcal
  • 1 gram of protein provides approx. 4 kcal

Our Energy Requirement

Energy requirements vary from person to personThe amount of energy we need each day depends on many factors. In addition to our age and gender, body weight and physical activity also play a part. The following overview shows the average amount of energy required across different age groups.

How much Energy (Calories) should we intake daily? 

Guideline values for average energy intake. RDA for Energy for Indians, 2010

Age group RDA(Kcal/day)
Adult Sedentary Male 2320
Adult Sedentary Female 1900
Pregnant Female 2250
Lactating Mother (0-6 months) 2500
(6-9 months) 2420
Infant (0-6 months) 496
(6-12 months) 672
Children 1-3 years 1060
4-6 years 1350
7-9 years 1690
Boys    10-12 years 2190
13-15 years  2750
16-17 years 3020
Girls 10-12 years 2010
13-15 years 2330
16-17 years       2440

Input must equal output

People who consume more energy than their body needs for an extended period will put on weight. It is therefore important to eat in moderation to keep your body weight within a healthy weight range. Are you carrying a few excess pounds? Then a combination of more exercise and reduced calorie intake is the most effective way to get back to your ideal weight.

To maintain energy balance, input must equal the output, which corresponds to a  steady state of equilibrium which helps in maintaining good health.

Source Of Energy In Indian Diets:

The main source of energy in Indian diets are carbohydrates, fats and protein. But the main source is carbohydrates derived largely from cereals present in them. These cereals constitute 80 % of our diet, and provide 50-80% of daily energy intake. Most families derive nearly 10-12 % energy from proteins. Energy from fats vary according to family type. Those belonging to low income groups have only 5 % fat in their diet whereas affluent families derive as high as 30 % of their dietary energy from fat

When Our Bodies Become Energy-Savers

A calorie-controlled diet can also be helpful when losing weight. However, not every diet is recommended. Make sure that your meals are varied and balanced and that the diet does not promise significant weight loss over a short period of time. It is especially important not to let a weight-loss diet become a matter of habit. While you are on this temporary diet, your body will adjust to receiving less energy. It becomes an "energy-saver”. As soon as you start eating normally again, the energy stores will fill up quickly to prepare for the next period of hunger. People's weight is often higher after they have been on a calorie-controlled diet than beforehand.