Nutrition and Diet
Nutrition and Diet
This domain tests balanced diets, macronutrients, micronutrients, deficiency diseases, energy balance, and safe food choices. The exam expects you to plan meals for adolescents and identify nutrient gaps.
Core concepts
Macronutrients are carbohydrates, proteins and fats; micronutrients are vitamins and minerals. Carbohydrates are the main energy source; proteins supply amino acids for growth and repair; fats carry fat-soluble vitamins and provide essential fatty acids. Fibre aids bowel function, and water regulates temperature and transport. A balanced diet contains variety, adequacy, moderation and balance. Deficiencies: iron causes anaemia, iodine causes goitre, vitamin A causes night blindness, vitamin D causes rickets, and calcium weakens bones.
Worked example
A vegetarian adolescent needs a low-cost lunch. Plan roti or rice with dal, seasonal vegetables, curd, and a citrus fruit. Reasoning: cereal proteins are low in lysine while pulses are rich in lysine, so cereal-pulse combinations improve protein quality. Iron from dal and green leafy vegetables is better absorbed with vitamin C from citrus. Curd adds calcium and protein. Deep-fried snacks and sweetened drinks add energy but few micronutrients.
Traps that cost marks
A fat-free diet is not balanced; some fat is essential. More protein is not always better. Supplements do not replace food variety. Fruit juice is not equivalent to whole fruit because fibre is reduced. Do not confuse deficiency with overdose: excess vitamin A and iron can be harmful. Energy balance depends on intake and activity, not one food.
Exam focus
For meal-plan questions, name the food group, the nutrient it supplies and the reason it is included.