Nutrition, Dietetics and Health Promotion
This domain covers energy and nutrients, deficiency diseases, diet planning and therapeutic diets, plus the principles of health promotion.
Nutrients and energy
Carbohydrate and protein supply 4 kcal/g, fat 9 kcal/g. A balanced diet supplies energy, protein, vitamins, minerals, fibre and water in proportion - cereals, pulses, milk and milk products, fruits and vegetables, fats and sugars. Protective foods are those rich in vitamins and minerals. ICMR recommends roughly 1 g of protein per kg body weight per day for adults.
Deficiency diseases
Vitamin A - night blindness and xerophthalmia; vitamin D - rickets and osteomalacia; thiamine (B1) - beriberi; riboflavin (B2) - angular stomatitis; niacin (B3) - pellagra with the three Ds (dermatitis, diarrhoea, dementia); vitamin C - scurvy; iron - anaemia; iodine - goitre and cretinism.
Body mass index
BMI = weight in kg divided by height in metres squared. WHO cut-offs: below 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30 and above obese. Indian guidelines lower this: 23 and above is overweight and 25 and above is obese.
Therapeutic diets
Diabetic diet (complex carbohydrates, no refined sugar), renal diet (restricted protein, potassium and sodium), low-sodium diet (under 2 g salt daily), high-protein and high-iron diets, and liquid, soft and full diets.
Worked example
A man weighs 60 kg and is 1.6 m tall. BMI = 60 ÷ (1.6 × 1.6) = 60 ÷ 2.56 = 23.4. Using Indian cut-offs, 23.4 is overweight, although WHO cut-offs would still call it normal - a common exam trick.
Health promotion
Ottawa Charter (1986) actions: build healthy public policy, create supportive environments, strengthen community action, develop personal skills, reorient health services. National programmes include POSHAN Abhiyaan and ICDS.
Traps that cost marks
Using 9 kcal/g for protein; quoting WHO BMI cut-offs for Indian patients; mixing up pellagra and beriberi.