Energy balance & requirements

Energy balance definition

Energy intake minus energy expenditure

Positive energy balance

Intake greater than expenditure

Negative energy balance

Expenditure greater than intake

Consequences of positive energy balance

Obesity, growth, pregnancy, recovery

Consequences of negative energy balance

Wasting, anorexia, voluntary weight loss, starvation

Three components of energy expenditure

BMR, thermic effect of food, physical activity

Thermic effect of food percentage

10% of total expenditure

Factors affecting energy expenditure

Body size, composition, age, sex, climate, genetics, disease

Rule of thumb REE

20–35 kcal/kg/day

MSJ equation use

Patients with BMI over 30

MSJ equation men

(10×weight)+(6.25×height)-(5×age)+5

MSJ equation women

(10×weight)+(6.25×height)-(5×age)-161

PAL definition

TEE divided by REE

In‑patient PAL value

1.25

Effect of fever on BMR

10% increase per 1°C rise

Energy requirement in metabolic stress

Use 30 kcal/kg/day

BMI underweight

Less than 18.5

BMI healthy

18.5–24.9

BMI overweight

Over 25

BMI obesity class I

30–34.9

BMI obesity class II

35–39.9

BMI obesity class III

Over 40

Anthropometry components

Height, weight, BMI, skinfolds

Skinfolds measure

Subcutaneous fat

South Asian BMI risk threshold

23 for overweight, 27.5 for obesity

Dietary assessment methods

Food diary, 24‑hour recall, food frequency questionnaire