What is a calorie ?

A calorie is a unit of measurement of energy. Calorie is the amount of heat energy required to raise the temperature of one gram of water by one degree Celsius, specifically from 14.5 degrees to 15.5 degrees.

The kilocalorie which is equal to 1000 calories is the unit commonly used for measuring the amount of energy which food provides. The calorie continues to be widely used for measuring energy content of foodstuffs and for estimating energy requirements of human being.

Calories provide the fuel to keep the human body going. They provide our body with the energy that we require to perform all our body functions. We require energy for survival to breathe, pump blood and for all kinds of physical activity like walking, running, sitting and working. Calories are required even when we are lying down or asleep. They are also expended in digestion of food and for making available the calories from that food to our body. They are essential for maintenance to our body temperature. Thus, adults require calories mainly for physical activities and involuntary body functions. In infants calories perform vital function of supporting growth and development.

Your caloric needs ?

Energy is required by all individuals for survival, growth and maintenance but energy requirements of different individuals are different. These requirements are based on three factors:

Basal or resting metabolic rate which is the amount of energy required by your body to carry out vital body functions at rest. This accounts for about 55% of total calories burnt in a day and includes the energy expenditure in activities like respiration, blood circulation, functioning of kidneys, maintenance of body temperature. Basal energy or basal metabolism is the energy expended by our body in a state of complete rest.

Thermic effect of food : It is the amount of energy that our body requires for digestion of food and absorption of nutrients. It also includes the stimulating effect of these nutrients on body metabolism.

Energy required for physical activity, depends on the type of occupation and the activity level. Physical activity includes making beds to jogging, walking, sitting, bending, moving.

For any given activity, the total number of calories that you burn will depend on your body weight. The greater your body weight, the more calories you burn in performing the same activity.

Depending on the calorie requirements the occupations are divided in to:

Sedentary:

Males: Teacher, Barber, Executive, Businessman, Shoemaker, Priest, Retired Personnel, Landlord, Peon, Postman etc.

Females: Teacher, Tailor, Executive, Businesswoman, Housewife, Nurse etc.

Moderate:

Male: Fisherman, Basket-maker, Potter, Goldsmith, Agricultural labourer, Carpenter, Mason, Rickshaw-puller, Electrician, Fitter, Turner, Welder, Industrial labourer, Coolie, Weaver, Driver etc.

Female: Maid servant, Coolie, Basket-maker, Weaver, Agricultural labourer etc.

Heavy:

Male: Stone cutter, Blacksmith, Mine-worker, Wood cutter, Gangman etc.

Female: Stone cutter.