Diet Designing : BMR,SDA and Calorie intake calculation.

Diet designing for an adult: BMR, Proximate principals, Calorie calculation, SDA, Balanced diet. For medical and dental and nursing students

1. Energy requirement of normal person
Energy required for
•BMR-Basal Metabolic Rate
•SDA- Specific Dynamic Action
•Extra energy expenditure for physical activities are
to be considered while calculating energy needs of
a person.

2. BMR
•Definition: energy required by an awake individual
during physical, emotional and digestive rest.
•It is the minimum amount of energy required to
maintain life or sustain vital functions like heart beat,
circulation of blood, brain function, respiration etc.
•The metabolic rate during sleep < BMR.

3. •BMR is measured directly by heat evolved, or indirectly
by the volume of oxygen consumed and carbon dioxide
released per unit time.
Factors affecting BMR:
Age:
During period of active growth, BMR increases.
Max BMR attained by 5 yrs of age.
and later as age increases, BMR decreases

4. Sex:
Males have higher BMR than females
Temperature:
Cold climates --- increases BMR
Exercise:
Increases BMR -- cardiac out put increases.
Starvation --- decreases BMR

5. Fever:
1°C rise in temperature – increase BMR 12%.
Thyroid Hormones:
Hyperthyroidism --- increases BMR
Hypothyroidism --- decreases BMR
Normal Value of BMR for adult male is 34 to 37
kcal/m2 /hour.
BMR for adult is fixed at 24 kcal/kg body wt/day.

6. SDA
•SDA refers to increased heat production or increased
metabolic rate following the intake of food (diet
induced thermogenesis).
•This is due to expenditure of energy for digestion,
absorption and active transport products of digestion.
And also due to synthesis of glycogen and TAG from
absorbed biomolecules.

7. •This energy is trapped from previously available energy,
so that actual energy from food is lesser than that of
theoretical calculation.
•SDA can be considered as an activation energy needed
for a chemical reaction. This activation energy needed
to be supplied initially.

8. •Eg: 250 g of carbohydrate should produce 250*4 = 1000
kcal. But before this energy is trapped, about 10%, 100
kcal is drawn from the existing reserves of the body.
•Thus the net production of energy is only 1000 – 100 =
900 kcal.
•If the person wants to get 1000 kcal, he should take
food worth 1100 kcal.
•Thus, additional calories, equivalent to SDA has to be
added in the diet.

9. •SDA for proteins = 30%
lipids = 15%
carbohydrates = 5%
Hence for mixed diet, an extra 10% calories should be
provided to account for the loss of energy as SDA.

10. Energy calculation
General Principles
•The ideal body weight:
For adult male is 48 Kg for a height of 153 cm, ±1.25 Kg
for every cm
For adult female is 45 Kg for a height of 153 cm, ±1.0 Kg
for every cm
Protein Requirement:
Adults: 1g per Kg body weight.
Children: 2 g per Kg body weight.
Pregnant & lactating female: 2 g / Kg body wt.

11. Calorie requirement
•Depends on age, sex, height, weight, health status, physical
activity and occupation.
•For an adult with ideal body wt, the calorie requirement is
taken as 30-35 Kcal/Kg body wt.
•For sedentary worker, lower value (30 Kcal) is considered
and for heavy worker highest value (35 Kcal) are prescribed.
•The average an Indian weight considered as 55-65 Kg, the
average calorie requirement will be 1700 to 2300 Kcal per
day.

12. •During preganancy and lactation period an
additional allowance of 300 k cal is necessary.
Specific Dynamic Action (SDA):
extra energy to be supplied for SDA (10% of
requirement)
•Ratio: Carbohydrate, Proteins and Fats to be
supplemented in the ratio of 60:20:20.

13. •The steps in prescription of balanced diet
1.Calorie requirement.
2.Proximate principles.
3.General composition of food.
4.Determine the items of food.

14. •1. calorie requirement:
•Average 60 Kg sedentary man, calorie required is 60*30=
1800 Kcal
•For SDA, 1800*10% = 180 kcal
•Total calorie requirement is = 2000 Kcal/day.
First step in the prescription of diet
Energy required + SDA 2000 kcal
Protein (60*1g) 60 g
Calcium 400 mg
Iron 25 mg

15. 2. Proximate Principles
60 g protein will give 60 x 4 = 240 kcal
Total requirement is 2000 kcal
Carbohydrates + fats should provide, 2000 – 240 =1760 kcal.
20% of calories must provided by fats ie 1760 = 350 kcal.

16. Prescription of diet, second step
Proteins 60 g
Fats 35 g
Carbohydrates 350 g
Calories 2000 Kcal
Calcium 400 mg
Iron 25 mg
For supply 350 kcal, 350/9 = ~ 35 g of fats to be
supplemented in the diet.
Remaining 1400 kcal must provide by carbohydrates,
1400/4 = 350 g of carbohydrates required in the diet.

17. 3. General composition of food
This step is to calculate how these proximate
principles are supplied as common foodstuffs.
The simplified version is given in table below.

18. Balanced diet for adult man
Food type Sedentary work Moderate work Heavy work
Veg Non veg Veg Non-VegVeg Non-Veg
Cereals (g) 400 400 475 475 650 650
Pulses (g) 70 55 80 65 80 65
Green leafy veg (g)100 100 125 125 125 125
Other veg 75 75 75 75 100 100
Roots&Tubers 75 75 100 100 100 100
Fruits 30 30 30 30 30 30
Milk 200 100 200 100 200 100
Fats& oils 35 40 40 40 50 50
Meat& flesh --- 30 -----30 ---- 30
Eggs --- 30 -------30 ------30
Sugar 30 30 40 40 55 55
Groundnut ----------- ------------50 50

19. •Step-4, Determination of food items
•“Food exchange” is used to calculate proximate principles.
•Foods with similar nutrient composition are grouped
together.
•Mutual supplementation of Cereals and Pulses
•A judicious combination of cereals and pulses provide all
the essential amino acids.
•Pulses lack in Met.
•Cereals lack in Lysine.
•The food with combination of cereals and pulses will
supply good quality proteins.

20. •5-step: Three meals per day
•The total quantities of proximate principles,
thus calculated are divided into breakfast,
lunch and supper.