Food, Nutrition and Health
This domain asks you to relate nutrients to functions, deficiency diseases and food sources, and to judge whether a described diet is balanced. Definitions of balanced diet, the ICMR food groups, and the classic deficiency diseases are tested repeatedly.
Nutrients and their jobs
- Energy: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g.
- Body building: protein, minerals.
- Protection and regulation: vitamins, minerals, water, fibre. A balanced diet supplies all nutrients in the amounts needed for age, sex, activity and physiological state (pregnancy, lactation), with enough variety.
ICMR food groups
Cereals and millets; pulses and legumes; milk and meat products; fruits and vegetables; fats, oils, nuts and sugars. Cereals are staples, not merely "energy foods" - they also supply protein and B vitamins.
Deficiency diseases
- Protein-energy malnutrition: marasmus (severe wasting, no oedema) and kwashiorkor (oedema, moon face, hair and skin changes).
- Vitamin A: night blindness, xerophthalmia. Vitamin D: rickets in children, osteomalacia in adults.
- Iron: anaemia. Iodine: goitre, cretinism. Vitamin C: scurvy.
- Thiamine (B1): beri-beri. Riboflavin (B2): ariboflavinosis, cracks at mouth corners. Niacin: pellagra - dermatitis, diarrhoea, dementia. Calcium: poor bone growth.
Worked example
A 2-year-old has swollen feet, a moon face, thin peeling skin and lives on rice water alone. Reasoning: oedema plus a protein-poor diet points to kwashiorkor, not marasmus (wasting without oedema). Answer: protein-energy malnutrition; add milk, egg, dal and groundnut; refer to a health worker.
Traps
Using 4 kcal/g for fat; naming vitamin D for night blindness; confusing pellagra (niacin) with beri-beri (thiamine); writing "malnutrition" only for undernutrition, when obesity is overnutrition.