Nutrition and Lifestyle
What this domain tests
Questions test a balanced diet, nutrient functions, energy values, hydration, food labels and lifestyle risk. You should calculate simple energy shares and distinguish evidence-based guidance from fads.
Core rules and concepts
- A balanced diet supplies energy, protein, essential fats, vitamins, minerals, fibre and water in appropriate proportions.
- Energy values: carbohydrate 4 kcal/g, protein 4 kcal/g, fat 9 kcal/g. Alcohol is 7 kcal/g but is not a nutrient need.
- Macronutrients: carbohydrates (main energy, fibre), proteins (growth/repair), fats (energy, cell membranes, fat-soluble vitamin absorption).
- Micronutrients: vitamins and minerals; deficiency diseases matter, e.g., iron-deficiency anaemia, iodine-deficiency goitre, vitamin A night blindness.
- Indian dietary guidance emphasises cereals/millets, pulses, milk/curd, fruits and vegetables, nuts/oils, and limited salt, sugar and ultra-processed foods.
- Hydration: water needs vary with climate and activity; thirst and pale urine are practical cues.
- Lifestyle: no tobacco, avoid alcohol, daily activity, adequate sleep, stress management, food safety.
Worked example
A 2,000 kcal diet with 50% carbohydrate, 20% protein and 30% fat gives 1,000 kcal carbohydrate ÷ 4 = 250 g; 400 kcal protein ÷ 4 = 100 g; 600 kcal fat ÷ 9 ≈ 67 g. Reasoning: percentages must be converted using the correct kcal/g value; a common error is dividing all three by 4.
Traps that cost marks
- Calling a food healthy because it is fat-free or labelled natural.
- Forgetting fibre and water.
- Treating supplements as substitutes for food.
- Using BMI or weight alone to judge diet quality.
- Ignoring portion size and ultra-processed foods.
Key takeaway: balance, variety, moderation and calculation accuracy.