Food is digested, the complex nutrients i.e., carbohydrates, fats, protein are counteracted into monosaccharides, fatty acids & glycerol, & amino acids, respectively. These simple forms are absorbed into the bloodstream & supplied to the variant cells within the body to be oxidized by series of complex steps to released energy.
The human being needs energy for the following:
- Basal metabolism
- Metabolic responses to food – thermogenesis / SDA
- Physical activities
- For mothers in special conditions (pregnancy & lactation)
TEF = BMR (45 – 75percent) + Thermogenesis (10 percent) + Physical activities (15 – 50 percent)
Factors affecting the BMR.
BMR is that the most important component of the daily energy demand representing 45 – 70 percent of daily total energy expenditure. it is highly variable & the rationale behind this variation include factors like
- body size & composition,
- environmental condition,
- hormonal status,
- specific body conditions of mothers (pregnancy & lactation),
- other factors, etc
Thermal effect of food (SDA)
Thermal effect of food (TEF) determined primarily by the number of the composition of food consumed. For example, is greater after consumption of carbohydrate & protein than after fat.
Sedentary workers –persons taking, reading, watching TV, listening Radio, doing computer works specially sitting activities (teachers, office workers).
Moderate workers – with some activity’s servants, house cleaners, rural woman’s, students etc.
Heavy workers – Labour class.
Energy requirement the amount of food needed to create a sure physiological state will vary from one individual to a unique one. All people do not require an identical amount of nutrients. Requirements vary depending upon age, gender, body size, activities, state of health, etc. ICMR has prepared Recommended Dietary Allowances(RDA) for Indians.
Energy balance: Energy output – Energy input
Energy balance may be a condition within which the energy provided by food is kind of up to energy expenditure by the body resulting in a gradual weight. Overweight & underweight both are abnormalities Both measured by BMI (Body Mass Index)
BMI = Weight in kilograms/height in meters squires