GLOSSARY

Macronutrient is a nutrient needed in relatively large amounts. In common sports-nutrition usage, carbohydrate, protein and fat form this group. Some sources also include water because of the quantity required, so the intended classification should be made clear.

A meal of rice, chicken and olive oil illustrates all three energy-yielding macronutrients; their contributions depend on actual portions. There is no single ideal ratio for every athlete. Total energy and grams of each nutrient are often more useful for planning than looking only at percentages on a chart.

• Energy: Digestible carbohydrate and protein provide approximately 4 kilocalories per gram, and fat approximately 9. These factors support estimation rather than capturing every digestive difference. Vitamins, minerals, and water have vital roles but do not directly supply calories.
• Food mixtures: Most foods provide several nutrients together. Lentils, for example, contain carbohydrate and fibre as well as protein, while milk can provide protein and calcium. Assigning each food to just one nutrient therefore simplifies its actual composition.