| Abstract: | Mathematical optimisation of diets is generally used to translate nutrient‐based recommendations into healthy food choices but can also be used to assess the possible impact of food‐based dietary guidelines (FBDG) on nutrient intakes. Optimisation of individual diets, which allows individual variability of food consumption to be taken into account, generates more robust results and more realistic diets than population diet optimisation. It was used to simulate the impact on nutrient intakes of complying with the new French FBDGs. For each observed diet of adults in the French INCA2 survey, a new isoenergetic diet was designed to meet all food consumption frequencies recommended by the new French FBDGs, as interpreted by the constraints included in a model called DP2. Because the dairy food group is the only one whose guideline has been reduced (from 3 to 2 portions/day) compared to the previous FBDGs, an alternative model, called DP3, imposing 3 daily portions of dairy products instead of 2 was also tested. Diets optimised with the DP2 model had lower energy density and higher nutrient density than the observed diets, and inadequate intakes decreased for most vitamins and minerals. With the alternative DP3 model, the decrease in saturates was less pronounced than with 2 portions/day of dairy products (13.8%, 11.9% and 12.8% energy in observed diets and in DP2 and DP3, respectively), but calcium adequacy was improved instead of being worsened (51%, 58% and 16% of inadequacy in observed diets and in diets modelled with 2 portions/day and 3 portions/day of dairy products, respectively). Individual diet optimisation is a powerful tool for assessing the nutritional relevance of existing FBDGs and to test possible alternatives. |
