Ultra-Processed Foods in Childhood Linked to Higher Adult BMI: Study

The increasing consumption of ultra-processed foods (UPFs) worldwide has often been pointed out as the main cause of the obesity epidemic; however, it seems to be that people have different reactions to the same diet patterns. In order to investigate this interaction, scientists relied on the data collected within the context of the Avon Longitudinal Study of Parents and Children (ALSPAC). This longitudinal study is well-known among researchers since it is one of the most prominent birth cohorts in England.

It was used to evaluate the relationship between UPFs consumed in childhood and BMI in adulthood in 3,061 subjects who were followed up for 17 years from the age of seven until age 24. The dietary information provided by ALSPAC was obtained by the means of food diaries. It has been analyzed based on the criteria established within the NOVA classification of foods that have been heavily processed industrially. In order to estimate the genetic predisposition, the researchers constructed a polygenic score (PGS) based on LDpred2 for the Body Mass Index (BMI).

Key findings:

• It was found on average that each additional 10% increase in UPFs as a share of energy intake at the age of 7 corresponded to 0.21 kg/m² (95% CI 0.05-0.37) increase in BMI in 24 years old.
• Nonetheless, the more surprising finding is that of the interaction of the polygenic score and the diet factor.
• There was statistical evidence of an interaction between the polygenic score and BMI (0.19; 95% CI 0.02-0.36).
• The analysis of subgroups showed that the effect of the relationship between intake of processed food and BMI in adults remained in children with high genetic predisposition only.
• Among children who had a high genetic predisposition, there was much stronger influence with the result being 0.74 kg/m² (95% CI 0.07-1.42), but it vanished among low-risk subjects.

The prospective research on the effects of UPFs consumption among the ALSPAC population gives unequivocal proof of the role genetics play in the effect of UPF consumption during childhood in the long term. As shown, a 10% increase in energy from UPFs at age 7 was associated with an increase in adult BMI, but solely in those individuals with higher genetic risk. Considering the 0.74 kg/m² increase in adults with the high genetic risk against the absence of any increase in the case of those individuals with lower genetic risk, this research clearly indicates the influence of genetic susceptibility on the effect of dietary factors on BMI in young adulthood.

Reference:

Zhou, Z., Chen, Q., Li, Z. et al. Genetic predisposition to high BMI, ultra-processed food consumptions in childhood, and adiposity in young adulthood: a 17-year prospective cohort study of 3061 individuals. BMC Med 24, 251 (2026). https://doi.org/10.1186/s12916-026-04764-5