Basal metabolic rate (bmr) and basal metabolic index (bmi) (mushtaq ahmed and chatergi0

BASAL METABOLIC RATE (BMR) and �BASAL METABOLIC INDEX (BMI)

All energy is provided by three classes of nutrients: Macronutrients
Fats
Carbohydrates
Protein
Ethanol provide energy in some diets
Energy production can be measured
Heat output from the body
Amount of O2 consumed
It is calculated from the heat released by the total combustion of food in a calorimeter
It is expressed in kilocalories (kcal, or Cal)
The energy generated by metabolism is used for three energy-requiring processes:
Resting metabolic rate (RMR)
Physical activity
Thermic effect of food
Total Energy Expenditure (TEE): The number of calories expended by these processes in a 24-hour period

1. BASAL METABOLIC RATE (BMR) and BASAL METABOLIC INDEX (BMI) Maryam Fida (o-1827)

2. Energy Production in body All energy is provided by three classes of nutrients: Macronutrients Fats Carbohydrates Protein Ethanol provide energy in some diets Energy production can be measured Heat output from the body Amount of O 2 consumed

3. Energy content of food It is calculated from the heat released by the total combustion of food in a calorimeter It is expressed in kilocalories (kcal, or Cal)

4. Calorimeter

5. Use of food energy in the body The energy generated by metabolism is used for three energy-requiring processes: Resting metabolic rate (RMR) Physical activity Thermic effect of food Total Energy Expenditure (TEE) : The number of calories expended by these processes in a 24-hour period

6. Resting Metabolic Rate (RMR) or Basal Metabolic Rate (BMR) It is the energy expenditure by the body At rest, Awake, Under controlled condition In terms of O 2 consumed or CO 2 produced Measured at post-absorptive state (12 hours after meal) Measured in Kcal/ hr /m 2

7. Normal BMR values Age BMR Value New born baby 25 Kcal/ hr /m 2 Premature baby 20-22 Kcal/ hr /m 2 Upto 6 years 45 Kcal/ hr /m 2 Adult male 40 Kcal/ hr /m 2 Adult Female 37 Kcal/ hr /m 2

8. Factors affecting BMR Weight More weight  more tissues  more metabolism  More BMR Age Decreases with age, in old age less active Gender Women have lower BMR than Men Reason is Hormonal differences, body composition difference Level of physical activity More activity  High BMR Less Activity  Less BMR Weather conditions High Temperature  More BMR Low Temperature  Less BMR Fever High BMR

9. BMR If there is a 5-10 % change from standard BMR values, then it is ignored But if more change  Dangerous For example, A male has BMR= 51.5 Kcal/ hr Normal BMR= 40Kcal/ hr Difference is more than 5-10 % (11.5 Kcal) Thyroxin is the hormone responsible for High BMR

10. Hyperthyroidism Thyroxin Secretion is more So more metabolic activity More O 2 consumption High BMR People with high BMR never gain weight They have high BP, high respiration rate, high heart beat

11. Hypothyroidism Less Thyroxin secretion Less metabolic activity Less O 2 consumption Low BMR People with hypothyroidism are usually obese (fat) Have less BP, Less HR, less RR

12. Basal Metabolic Index (BMI) Used for the assessment of obesity An indirect measure, the body mass index (BMI) Measuring the waist size In men, waist size ≤ 40 inches In women, Waist size ≤ 35 inches If more than 40 and 35, risk factor for CHD

13. BMI BMI = (weight in kg)/(height in meters) 2 The healthy range for the BMI is between 18.5 and 24.9 Overweight= 25 and 29.9 BMI Obese= more than 30 BMI Extremely Obese =more than 40 BMI Severely obese = More than 100 pounds

14. Anatomic differences in fat deposition