Diet, nutrients and a balanced plate
Biology · Key Stage 3 · The School
The main nutrient groups
CARBOHYDRATES provide energy, and are the body's preferred quick-access fuel. PROTEINS build and repair cells and tissues, particularly muscle. FATS store energy long-term and build cell membranes and hormones. VITAMINS and MINERALS are needed in small amounts for many separate specific jobs — vitamin C for healthy skin and gums, calcium for bones and teeth. FIBRE keeps the digestive system working properly, and WATER is needed for essentially every process in the body.
Balance, not elimination
A genuinely balanced diet includes ALL of these groups, in roughly the right proportions for a person's age, activity level and health needs — not the complete removal of any single one. Cutting out fat entirely, for instance, removes nutrients the body genuinely needs, rather than simply removing something harmful.
Reading a nutrition label
A food label typically states energy (in kcal or kJ), and the amount of fat, saturates, sugars, salt, protein and carbohydrate per 100g and per portion. Comparing the PER 100G figures, not the per-portion ones, is the fair way to compare two different products, since portion sizes printed on packets often differ between brands.
Cereal A: 380 kcal per 100g, 24g sugar per 100g. Cereal B: 410 kcal per 100g, 8g sugar per 100g. Reading only the "per portion" figures, if Cereal A's stated portion is 30g and Cereal B's is 45g, Cereal A could look lower in both energy and sugar per portion purely because its stated portion is smaller — not because it is actually the healthier food per gram. Comparing per 100g instead shows the true picture: Cereal B has more energy per 100g but far less sugar. Which matters more depends on what you are trying to manage, but the per-100g figures are what makes a fair comparison possible at all.