The nutrient content of a cooked foodstuff or a composed dish can either be analysed or calculated. Analysis has the advantage that it delivers exact values. However, analyses are demanding, time-consuming and expensive. In practice, the nutrient content of a prepared product is therefore mostly calculated using average loss factors and absorption factors. This also the case for the Swiss Food Composition Database.
When calculating the nutrient content of a prepared foodstuff, possible weight changes in addition to the nutrient losses also have to be taken into account. A weight loss corresponds to a concentration. The vitamin and mineral contents per 100 g of a cooked foodstuff can therefore turn out to be higher than those of the corresponding raw products in spite of nutrient losses. Conversely, a weight gain (e.g. when cooking pasta) corresponds to a dilution and the nutrient content per 100 g of the cooked foodstuff is significantly lower than that of the uncooked, dry foodstuff.