An alternative term for calorific values: the amount of energy a food provides when metabolised, usually expressed in kilocalories or kilojoules. They appear on nutrition labels and underpin dietary planning, product formulation, energy-balance calculations and claims about low-energy or reduced-energy foods. Atwater factors assign 4 kcal/g to protein and carbohydrate, 9 kcal/g to fat and 7 kcal/g to alcohol, with fibre counted at around 2 kcal/g in the EU. Bomb calorimetry measures gross energy, but metabolisable energy — the Atwater figure — is what labels declare, and it underpins front-of-pack schemes and dietetic planning.