Consumption of ultra-processed foods is associated with dietary iron availability, anemia, and excess weight in socially vulnerable children.

Background & aims: Eating habits during childhood have undergone significant changes, with a notable increase in the consumption of ultra-processed foods (UPF). This situation deserves attention, given the close relationship between UPF and adverse health outcomes. This is due to the nutritional composition of UPF, which has high levels of health-critical nutrients such as sugar, fat, and sodium, thus compromising the overall quality of the diet. An excess of these nutrients can increase the risk of developing excess weight, nutritional deficiencies, and chronic diseases during childhood. Among the nutritional deficiencies is iron. This is due to the fact that UPF are not good sources of iron. This, combined with the fact that UPF is low in nutrients that help make iron more available, such as vitamin C, increases the risk of developing anemia. Therefore, this study aimed to assess the availability of iron, as well as the presence of anemia and excess weight in children living in situations of social vulnerability, and to determine their association with the consumption of UPF.

Methods: This is a population-based cross-sectional study. Children aged between 6 and 59 months living in slums were included. The presence of excess weight was assessed by measuring weight and height, and the presence of anemia was determined by hemoglobin concentration, assessed using the HemoCue portable hemoglobinometer. A 24-h food recall was also used to assess the relative calorie intake of UFP and the dietary availability of iron using an algorithm. All statistical analyses were carried out using the statistical software Jamovi.

Results: In this study, 443 children were included; 19.2 % were classified as with excess weight, and 55.6 % were anemic; the average absorbable iron content was 0.54 (SD ± 0.42) mg, and 39.2 % of the calories consumed came from UPF. The association analysis showed that children with calorie share relative to UPF had a decrease of -0.12 mg of bioavailable iron (β: -0.12; 95 % CI: -0.23; -0.01). It was also possible to identify that the higher calorie share of UPF increased their chances of being classified as with excess weight and anemic by up to 116 % (OR: 2.16; 95 % CI 1.05; 4.46) and 145 % (OR: 2.45; 95 % CI: 1.26; 4.78), respectively.

Conclusions: The relationship found between UPF consumption and the availability of iron in the diet, excess weight, and anemia calls for attention, especially in contexts of social vulnerability. These findings demonstrate the need for greater attention to nutrition in childhood to promote an adequate and healthy diet. This can help to change the nutritional and epidemiological panorama of the population, contributing to a better general state of health for future generations of adults.