Evidence of Unhealthy Dietary Patterns in the School Lunch Sent from Home for Children in Mexico City

The identification and characterization of dietary patterns are tools that are used to assess associations between diet and health or disease conditions. In Mexico, studies have examined dietary patterns in children for breakfast or for the whole day, but not specifically for their school lunch. The aim was to describe dietary patterns identified in school lunch and their association with the nutritional status and metabolic parameters of schoolchildren. In this cross-sectional study on schoolchildren from four elementary schools of Mexico City, we recorded anthropometry measurements, a fasting blood sample was collected, and metabolic parameters were determined. We obtained information on the foods and beverages that children brought for their school lunch; estimated the caloric and nutritional content; and created food groups to obtain dietary patterns from the energy provided by those groups. Among the 350 schoolchildren (mean age, 7.9 +/- 1.2 years) included, 24.9% and 21.7% presented having overweight and obesity, respectively. A total of 89.4% of schoolchildren brought the school lunch from home. Using the K-means method, the following four dietary patterns were identified: (1) sandwiches, tortas, and sweetened dairy products were consumed by 13.1% (n = 46) of the schoolchildren; (2) sweet snacks were consumed by 50.3% (n = 176); (3) sweetened dairy products were brought by 15.1% of the children (n = 53); and (4) sandwiches and tortas were brought by 21.4% (n = 75). These four patterns showed significant differences in terms of the caloric and nutritional contents (p < 0.001). Energy sources in the identified patterns were primarily sugars (15.8-40%). No association was found between the anthropometric and metabolic parameters of children and the dietary patterns. No dietary pattern obtained from the school lunch could be considered as healthy, since all of them had high energy content, and a high percentage of the energy was from sugars from ultra-processed foods and beverages.