Evaluation of calculated energy and macronutrient contents of diets provided in controlled dietary intervention trials by chemical analysis of duplicate portions

The purpose of this study was to investigate whether Dutch food composition databases (Dutch-FCDB) are accurate enough to plan experimental diets with specified amounts of energy and macronutrients. From 2003 to 2012, 10 controlled dietary intervention trials lasting from 2 to 13 weeks were conducted in different seasons. The energy, macronutrients, dietary fibre, water and fatty acids contents of the test diets were calculated with 3 releases of the Dutch-FCDB and compared with the chemically analyzed nutrients in 25 duplicate diets, except for fatty acids which were analyzed in 10 diets. Calculated values of energy and macronutrient content, especially carbohydrates, were higher than values based on analysis. Correlation coefficients ranged from 0.57 for energy to 1.00 for polyunsaturated fatty acids (PUFA). Bland-Altman plots showed considerable differences for the individual diets, limits of agreement (mean ±1.96 SD) were −11.0 to +11.0 g/day for protein, −14.2 to +21.6 g/day for total fat, −4.8 to +57.0 g/day for carbohydrates and −10.7 to +11.5 g/day for dietary fibre. We therefore conclude that Dutch-FCDB can be considered accurate enough for planning of experimental diets to be provided in controlled dietary intervention trials.