Selection of food table codes for foods prepared with fat and for mixed dishes: Impact on estimated nutrient intake

The aim of the study was to examine how selection of different food composition table codes for foods prepared with fat and for mixed dishes affected estimated intake of energy and nutrients from 24-h dietary recalls collected in a nationwide Norwegian cohort. Four different coding alternatives were applied (2×2 design): (1) A food prepared with fat was coded as a raw or boiled food and preparation fat. A mixed dish was coded ingredient by ingredient. (2) A food prepared with fat was coded as a raw/boiled food and preparation fat. A mixed dish was coded as one single food. (3) A food prepared with fat was coded as a single, fat-prepared food. A mixed dish was coded ingredient by ingredient. (4) A food prepared with fat was coded as a single, fat-prepared food. A mixed dish was coded as one single food. Generally, the four different alternatives gave only small and non-systematic differences in estimated energy and nutrient intake. Energy intake varied within 1% and energy percentage from fat within <3%. The largest difference was found for vitamin C, which was about 5% higher when using values for ingredients as compared to values for mixed dishes. Obviously, the existence of appropriate values in the food composition table applied affects the results. The current results relate to the Norwegian food database.