Self-reported Slower Eating Is Associated with a Lower Salt Intake: A Population-based Cross-sectional Study

OBJECTIVE: Evidence suggests that the eating rate is positively associated with the body weight and blood pressure. Furthermore, people who are overweight or obese tend to have higher salt intakes than those of normal weight. To investigate whether or not the eating rate is also associated with the salt intake, a cross-sectional study was conducted using health examination survey data collected in 2014 from 7,941 residents of Sado City, Niigata, Japan. METHODS: The eating rates were evaluated using a questionnaire; 11.7% of participants rated themselves as slow eaters, 65.6% as normal eaters, and 22.7% as fast eaters. The salt intake was estimated from sodium and creatinine spot urine measurements using Tanaka's formula. Associations with eating rate were evaluated using multivariate linear regression analyses, with normal eaters as the reference (set at 0). RESULTS: Self-reported eating rates were positively associated with the salt intake after adjustment for age and sex [β coefficient (95% confidence interval) for slow -0.51 (-0.67, -0.35); fast 0.18 (0.05, 0.30)]. Further adjustment for the body mass index showed that slower eaters had lower salt intakes than normal eaters, but there was no marked difference in the salt intake between normal and fast eaters. The association between slower eating and a lower salt intake persisted after further adjustment for comorbidities [slow -0.33 (-0.49, -0.18)]. CONCLUSION: Our results suggest that reducing eating rates may be an effective strategy for reducing dietary salt intake as well as preventing obesity.