to express the proportion of an ingested nutrient that ultimately becomes available to the body cells. The coefficient of digestibility for carbohydrate, fat and protein are . , . and .
respectively. It is observed that carbohydrate and fat are metabolized almost completely, whereas protein metabolism is incomplete due to the presence of nitrogen. The physiological fuel value, Co- efficient of digestibility and digestibility percent of carbohydrate, fat and proteins is presented in table . .
. Basal metabolism Basal Metabolism is the minimum amount of energy needed by the body for maintenance of life when the person is at complete physical and mental rest and having normal body temperature and in the post -absorptive state ( hours after the intake of last meal). Basal Metabolic Rate (BMR) is a measure of the energy required by the activities of resting tissue. The Basal Metabolic rate can be measured directly from the heat produced Table .
Types and Sources of Carbohydrates Nutrient Heat of combustion (kCal) Co-efficient of digestibility Digestibility percent Physiological fuel value Carbohydrate . . . Fat .
. ACTIVITY - List the energy , protein and fat value of any commonly consumed foods (per 100g): a) cereals b) fruits c) nuts d) dairy products - - Carbohydrates and Energy Table . Factors affecting Basal Metabolic Rate (BMR) S.no Factor Effect on BMR Body composition More the lean body mass, higher is the BMR. This is due to greater metabolic activity in these tissues when compared to bones and fat.
Men with a high proportion of muscle mass or lean body mass have a higher BMR than women Fever Fever raises the BMR. There is a % increase in BMR for each degree rise in body temperature in Fahrenheit and % increase for every degree Celsius rise in body temperature Stress Raises BMR. Smoking and Caffeine Increases BMR Hyperthyroidism (Oversecretion of thyroxine) The basal metabolic rate is elevated as much as - %. Growth In tall people BMR is higher.