Optimization is the process of finding the optimal solution to a set problem that satisfies all set constraints. By applying optimization in diet therapy - the goal is to find the optimal offer that suits a particular diet. Using the LINDO program, linear optimization was performed to obtain an optimal solution, depending on the objective function, which will satisfy the energy and nutritional needs of the model. During the optimization, 21 variables were used (7 breakfasts, 7 lunches, and 7 dinners), which leads to possible 343 combinations of the daily menu. The number of combinations was reduced by introducing limits depending on the daily needs of the observed model. Restrictions apply to energy intake (e.g., restriction diet), macronutrients (proteins, carbohydrates, and fats), and micronutrients (sodium, vitamin C, and vitamin D). The objective function varied depending on the diet therapy required, and the limits remained unchanged. As a result of optimization, one-day menus with minimum and maximum intake of the observed nutrient were obtained. Although linear optimization is a good tool in diet planning, an additional analysis of optimal offers was conducted as the nutritionist assesses the acceptability of the offered optimal menu, which must be according to the principles of a varied diet and the user's preferences.