Diet modelling in the development of a healthy diet for the Ghanaian population

Diet modelling is one of the important steps in developing food-based dietary guidelines (FBDGs). However, this component remains uncommon in the FBDGs of many low-and middle-income countries. A diet modelling package (DietSolve) provided by the Food and Agriculture Organization (FAO) was used to formulate a healthy diet based on estimating the daily proportions of food groups that best meet the dietary goals established for the FBDGs for Ghana. Input data for the modelling included a list of commonly eaten foods across the agreed food groups, nutrient and energy content of the foods, current energy and nutrient consumption, and energy and nutrient constraints linked to the dietary goals, as determined by the FBDG multi-Sectoral Technical Task Team (MTTT). The modelling was based on assumptions and constraints including a total daily dietary energy target of 2000 kcal/day; the percentage contribution (energy targets) of the macronutrients as follows: carbohydrates (55-70%), protein (10-20%), and fat (20-30%) to the total energy target; and calcium (1100 mg/day), iron (20 mg/day), and zinc (11 mg/day) constraints. The situation analysis and evidence review carried out as a prior step guided the diet modelling constraints. Energy contributions were also set for a serving of each food group. The final recommendations were based on food groups with each food group consisting of a variety of commonly consumed foods. The total weight of the optimized diet was estimated at 1514 g/day, including 144g/day of animal-source foods, 41.5g/day of discretionary choices, 226g/day of fruit, 227g/day of vegetables, 6g/day of healthy fats and oil, 198g/day of legumes, nuts, and seeds, and 672g/day of staples. This food group composition will provide an estimated 2639 kcal/day, a deviation of about 32% above the energy target set, made up of ~59% from carbohydrates, ~15% from protein and ~25% from fat, and meeting/exceeding the micronutrient targets set. The Optimised diet is healthier compared to the present dietary patterns of the population; its lower ASF component is known to impact less on the environment.