Adiposity is not associated with caries among youth in the United States

Body mass index has been traditionally used to determine the nutritional status of children in studies on obesity and caries. Imaging methods provide a superior assessment of body fat. This study investigated the relationship between measures of adiposity and caries in permanent teeth in children and adolescents.

The analysis included 5,694 participants in the National Health and Nutrition Examination Survey from 2011 through 2018, aged 8 through 19 years. The body fat percentage (BF%) and fat mass index (FMI) were determined from whole-body dual-energy x-ray absorptiometry scans. Excess adiposity was defined as a sex- and age-specific value at or above the 75th percentile according to the US reference standards for BF% or FMI. Caries was measured with the decayed teeth and decayed, missing, and filled teeth indexes; prevalence of untreated dentin caries; and lifetime caries prevalence. The associations between adiposity and caries were tested in confounding variables-adjusted regression models.

The FMI score was associated with the decayed, missing, and filled teeth score (rate ratio, 1.03; 95% CI, 1.01 to 1.05) and lifetime caries prevalence (odds ratio, 1.06; 95% CI, 1.03 to 1.08), but the associations attenuated after adjustment for confounding variables. Neither the BF% score nor the presence of excess adiposity, defined according to the BF% or FMI reference standards, were associated with caries.

The authors found no association between measures of adiposity and caries among US children and adolescents.

Caries is a multifactorial disease, and any observed association between obesity and caries is most likely due to the shared determinants and risk factors of both conditions.