Human Nutrition 3(3+0)

Lesson 7 : Respiratory Quotient, SDA of Foods and Energy Requirements

Energy requirements

(Recommended Allowances For Energy For Indians, I.C.M.R., 1981)

The energy requirements of individuals are influenced by the following factors:

• Physical activity.
• Body size and composition
• Age
• Climate and other ecological factors.

1. Infants
   The energy requirements of infants during the first 6 months of life can be estimated from the observed intakes of breast milk by healthy infants from healthy mothers. An intake of 850 ml of human milk per day will provide on an average 120 Kcal per day during the first 3 months. From the 3rd month to 6th month, the energy intake from breast milk is slightly less. After 6 months of age, the quantity of breast milk secreted will be inadequate to meet the energy needs of the infant. The average energy requirements of the infant are as follows.



0-6 months	-	92 kcal/kg/d
6-12 months	-	112 Kcal/ kg/d



2. Adults
   The ICMR Committee expressed the energy requirements of adults in terms of ‘Reference Man’ and ‘Reference Woman’ doing moderate work. The definitions of ‘Reference Man’ and ‘Reference Woman’ given by the Committee are as below.


3. Reference Man
   He is between 20 and 39 years of age and weighs 55 kg. He is free from diseases and physically fit for active work. On each working day, he is employed for 8 hours in an occupation that usually involves moderate activity. When not at work, he spends 8 hours in bed, 4-6 hours sitting and moving around and two hours in walking in active recreation or in household duties.


4. Reference Woman
   She is between 20 and 39 year of age, healthy and weighs 45 kgs. She may be engaged for 8 hours in general household work, in light industry, or in other moderately active work. Apart from 8 hours in bed, she spends 4-6 hours sitting or moving around in only through light activity and 2 hours in walking, in active recreation or in household duties.



Effect of Physical Activity on Energy Requirement:

The energy requirements of ‘Reference Man’ and ‘Reference woman’ engaged in various types of physical activity are as follows:

Activity	Reference man	Reference woman
Low activity	2320 kcal	1900 kcal
Moderate activity	2730 kcal	2230 kcal
Heavy activity	3490 kcal	2850 kcal



5. During pregnancy and lactation
   The ICMR Committee recommended an additional allowance for the entire pregnancy distributed as follows: (i) 300 Kcal/day in the 2nd and 3rd trimester of pregnancy and (ii) The Committee has estimated the additional requirements, during the first 6 months of lactation as 550 Kcal per day and 7-12 months of lactation 400 Kcal per day.