The aim was to design culturally acceptable and healthy diets with reduced energetic share of ultra-processed foods (UPF%) at no cost increment and to evaluate the impact of the change in the UPF% on diet quality. Food consumption and price data were obtained from the Household Budget Survey (n 55 970 households) and National Dietary Survey (n 32 749 individuals). Linear programming models were performed to design diets in which the mean population UPF% was reduced up to 5 % with no cost increment relative to the observed costs. The models were isoenergetic or allowed the energy content to vary according to the UPF%, and they were not constrained to nutritional goals (nutrient-free models) or maximised the compliance with dietary recommendations (nutrient-constrained models). Constraints regarding food preference were introduced in the models to obtain culturally acceptable diets. The mean population UPF% was 23·8 %. The lowest UPF% attained was approximately 10 %. The optimised diet cost was up to 20 % cheaper than the observed cost, depending on the model and the income level. In the optimised diets, the reduction in the UPF% was followed by an increase in fruits, vegetables, beans, tubers, dairy products, nuts, fibre, K, Mg, vitamin A and vitamin C in the nutrient-constrained models, compared with the observed consumption in the population. There was little variation in most nutrients across the UPF% reduction. The UPF% reduction in the nutrient-free models impacted only trans-fat and added sugar content. UPF% reduction and increase in diet quality are possible at no cost increment.

中文翻译：

---

在经济实惠且文化上可接受的饮食中减少超加工食品并提高饮食质量：巴西使用线性规划的研究案例

目的是在不增加成本的情况下设计文化上可接受的健康饮食，减少超加工食品 (UPF%) 的能量份额，并评估 UPF% 变化对饮食质量的影响。食品消费和价格数据来自家庭预算调查（n55 970 户）和全国膳食调查（n32 749 人）。执行线性规划模型以设计饮食，其中平均人群 UPF% 减少了 5%，相对于观察到的成本没有成本增加。这些模型是等能的或允许能量含量根据 UPF% 变化，并且它们不受营养目标的限制（无营养模型）或最大限度地遵守饮食建议（营养受限模型）。模型中引入了关于食物偏好的限制，以获得文化上可接受的饮食。平均人口 UPF% 为 23·8 %。达到的最低 UPF% 约为 10%。优化的饮食成本比观察到的成本低 20%，具体取决于模型和收入水平。在优化的饮食中，UPF% 降低之后，水果、蔬菜、豆类、与观察到的人群消费量相比，营养受限模型中的块茎、乳制品、坚果、纤维、K、Mg、维生素 A 和维生素 C。在 UPF% 减少过程中，大多数营养素几乎没有变化。无营养模型的 UPF% 减少仅受影响反式-脂肪和添加的糖含量。在不增加成本的情况下，可以降低 UPF% 并提高饮食质量。