On her side, Nicole Darmon, PhD, Research Director at the National Research Institute of Agronomy (INRA), has examined how yogurt can fit into a nutritionally adequate diet.
Individual diet modeling with linear programming (2) was used to analyse and quantify the food changes needed to achieve a whole set of nutrient-based recommendations in a French adult population, with a focus on dairy products. From each individual weekly food intake (observed diets) of adults (n=1171) participating in the French national INCA (Enquête Individuelle et Nationale sur les Consommations Alimentaires) dietary survey, an isocaloric modelled diet was designed to simultaneously meet a whole set of nutrient recommendations (proteins, lipids, carbohydrates, fiber, essential fatty acids, 10 vitamins, 9 minerals, sodium, saturated fatty acids, cholesterol, and free sugars) while deviating the least from the observed food intakes.
The results indicated that, among seven main food groups, the quantities of three food groups had to be increased to reach nutritional adequacy, and the dairy group was one of them, together with fruit and vegetables (including nuts), and starches and grains. For all the food groups except the dairy one, their variation in energy contribution between the optimal diets and the observed ones followed their variation in weight.
For instance, the contributions of fruits and vegetables to both total diet weight and total energy intake had to be increased by one third, and that of added fats had to be reduced by one third. The dairy group behave differently, as its weight increased by about 19% while its energy contribution decreased by 14%. This was explained by a heterogeneity within the dairy group, with an increase (in weight) of fresh dairy products (+ 60%) and milk (+17%), a decrease of cheese (-48%), without significant change of dairy desserts.
Lastly, Darmon and her team quantified the changes needed, within the dairy group, that were compatible with the fulfillment of all nutrient recommendations. Cheeses represented one out of two consumed portions of milk-based products in observed diets, whereas in modeled diets cheeses, milk, and yogurts each represented about one portion per day. Milk desserts were similar before and after optimization, at approximately one portion per week.
These results confirm that a large increase in intake of plant-based products is needed. They show that rebalancing the intake of milk-based products in favor of the least energy-dense ones (i.e., yogurts and milk) will help individuals in this population reach nutritional adequacy.