Energy Vs Calorie both are same are different? How much energy is required to maintain our body?

Role of energy in our life

Many people consider energy as good and calorie as bad or fattening. Both are actually the same. Calorie or kilocalorie is the unit of measurement of energy. Energy is obtained by the oxidation of carbohydrates oils fat and the body protein contain in the diet as well as chemical reactions in the body. About half of the daily intake of energy is obtained from controlled oxidation of carbohydrates, fats and protein in the diet. It is used for self-maintenance, including: -

• Liberation of energy from glucose and fatty acids reaction
• Synthesis of new protein for growth and repair.
• Elimination of wastes blood by kidney.
• Maintenance of body temperature at 37 centigrade scale.
• Contraction of muscles in breathing.
• Contraction of heart muscles.

Rest half of the energy is used for muscular activity during the day and for special purposes such as growth, pregnancy and lactation.

Over short diet too high or too low in energy yielding nutrients is harmless. Excess energy is stored as fat or glycogen in the body. When less energy I consumed, it is drawn from the body fat or glycogen. During periods of starvation, body protein sis utilized to provide energy.

Energy expenditure

Human body require energy for performance of all functions. It is needed for maintenance of body temperature, continuous activities of the heart, lungs, kidneys, etc. as well as breakdown, repair and building of tissues. The rate at which these functions are carried out while the body is completely at rest is termed as basal metabolic rate (BMR). This is defined as the energy expended when the body is completely relaxed and at rest in a comfortable position in a temperature with in the zone of thermal neutrality and after digestion and absorption of the last food ingested has ceased.

Energy needs

Energy is primarily provided in the body through the oxidation of carbohydrates, fats, and protein. Minimum energy must be supplied for the basal metabolic reaction and body activities. The energy needs of an individual, however depends upon several factors such as the BMR, body weight, age, pregnancy and lactation, climate, and activity.

1. Body weight

Obese person uses less energy at rest, as fat cells are relatively inactive. During activity, use of energy is proportional to body weight.

2. Age

Children and adolescents require more energy in in proportion to their weight than adults do. Elderly generally use less energy than young and adults since the activity and number of active cells reduce with increasing age.

3. Pregnancy and lactation

Extra energy is required by women during pregnancy and breast feeding to fulfil the needs of the4 growing baby. Extra 200 kcal is recommended daily in the last 6 months of pregnancy. Extra 500 kcal are required daily when breast feeding.

4. Climate

Human beings maintain their body temperature at or around 37 degree Celsius. This is best suited to the activity of enzymes with heat continually dissipating during metabolism. Normally heat loss occur by radiation from the skin to the surrounding cool air.

In hot climates less heat is need to be generated to maintain the body temperature, hence food intake is reduced. Very cold climate does not always increase the need for energy to maintain body temperature since the amount of heat lost from the skin is reduced by increased clothing and home eating.

5. Activity

More energy is required during muscular activity when the body is at rest.