Amount and Frequency of Added Sugars Intake and Their Associations with Dental Caries in United States Adults

The relative importance of amount and frequency of sugars intake for caries development has been a matter of debate in recent years, yet only one study has formally evaluated this question among adults. The aims of this study were to explore the shape of the relationship between amount and frequency of added sugars intake and their associations with dental caries among adults. Cross-sectional data from 10,514 adults, aged 20+ years, from the National Health and Nutrition Examination Survey (NHANES) 2011–2016 were analyzed. The amount (g/day) and frequency (items/day and episodes/day) of added sugars intake were derived from dietary recalls. Dental caries was indicated by the DMFS and DS scores. Fractional polynomials were used to characterize the relationship between amount and frequency of added sugars intake. Their associations with DMFS and DS were evaluated in negative binomial regression models adjusting for confounders. There was a logarithmic relationship between amount and frequency of added sugars intake. The amount of added sugars intake was positively associated with the DMFS (rate ratio: 1.11, 95% CI: 1.07–1.15) and DS scores (1.43, 95% CI: 1.33–1.54). However, the estimates for frequency of added sugars intake varied depending on how it was expressed. When expressed in items/day, it was not associated with the DMFS (1.02, 95% CI: 0.99–1.04) or DS score (0.91, 95% CI: 0.81–1.02). When expressed in episodes/day, it was positively associated with the DMFS (1.43, 95% CI: 1.33–1.54) but not with the DS score (0.95, 95% CI: 0.86–1.04). This study found a curvilinear relationship between the amount and frequency of added sugars intake. Furthermore, the amount of added sugars intake was more consistently and strongly associated with dental caries than the frequency of intake.