Association between Number of Teeth and Eating out of Home: A 2019 Statistical Survey of the Japanese Representative Population.

Eating out of home (EOH), with its diverse food options, can benefit those with difficulty preparing their meals, especially older adults. Oral health status may be a determinant of EOH, as food accessibility is influenced by oral health, but this association remains unclear. This cross-sectional study used merged data from two national statistical surveys conducted in 2019. Participants were individuals aged ≥ 65 years who responded to both surveys. The frequency of EOH (<once/week or ≥once/week) was the dependent variable. The number of teeth was used as the independent variable (≥20, 10-19, 1-9, and 0). Prevalence ratios (PRs) and 95% confidence intervals (CIs) were calculated using multivariate Poisson regression analysis to identify the association between EOH and the number of teeth, adjusting for possible confounders. We analyzed 2164 participants (mean age = 74.0, women 52.4%). Of these, 456 (21.1%) participants were EOH ≥ once/week; 1142 (52.8%) participants had ≥20 teeth. Compared to those with ≥20 teeth, those with <20 teeth had a lower prevalence of EOH ≥ once/week (10-19: PR = 0.89, 95% CI = 0.72-1.09, 1-9: PR = 0.67, 95% CI = 0.51-0.89, and 0: PR = 0.53, 95% CI = 0.36-0.77, respectively). We observed an association between fewer teeth and a lower frequency of EOH.