Nutrition and Health: Nutrients, Deficiencies, BMI and Lifecycle Needs
What the exam tests
Nutrition and Health checks nutrient functions, deficiency recognition, balanced diets, BMI and lifecycle nutrition, with attention to Indian dietary guidelines.
Core rules
- Energy: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g.
- A balanced diet supplies energy, protein, vitamins, minerals, fibre and water in required proportions.
- Deficiency map: PEM - kwashiorkor (protein deficiency, oedema, moon face) vs marasmus (energy deficiency, severe wasting); anaemia - iron, folate, B12; goitre - iodine; beriberi - thiamine; pellagra - niacin; scurvy - vitamin C; rickets - vitamin D and calcium; night blindness - vitamin A.
- Iron absorption is enhanced by vitamin C and inhibited by tea, coffee and phytates.
- BMI = weight (kg) ÷ height (m)². WHO: overweight ≥25, obesity ≥30. Indian cut-offs: overweight ≥23, obesity ≥25.
- Lifecycle: pregnancy and lactation need extra energy, protein, iron, folate and calcium; adolescents need iron and calcium; the elderly need calcium, vitamin D and protein.
Worked example
A person weighs 60 kg and is 1.50 m tall. BMI = 60 ÷ (1.50 × 1.50) = 60 ÷ 2.25 = 26.7. Reasoning: 26.7 is overweight by WHO (25–29.9) but obese by the Indian cut-off (≥25). Both classifications should be stated with the standard used; do not call it “normal”.
Traps
- Swapping kwashiorkor and marasmus.
- Treating all anaemia as iron deficiency only.
- Mixing fat-soluble and water-soluble vitamins.
- Using BMI alone without waist measurement or diet context.