Dietary diversity predicts the mortality among older people: Data from the fifth Thai national health examination survey

Abstract

Objective: To examine the association between dietary diversity (DD) and mortality among Thai older people and to investigate whether age, sex, and nutritional status modify this association. Methods: The national survey conducted from 2013 to 2015 recruited 5631 people aged >60 years. Dietary diversity score (DDS) was assessed for the consumption of eight food groups using food frequency questionnaires. The Vital Statistics System provided the data on mortality in 2021. The association between DDS and mortality was analyzed by Cox proportional hazard model and adjusted for the complex survey design. Interaction terms between DDS and age, sex, and BMI were also tested. Results: The DDS was inversely associated with mortality (HRadj 0.98, 95%CI: 0.96–1.00). This association was stronger in people aged >70 years (HRadj 0.93, 95%CI: 0.90–0.96 for aged 70–79 years, and HRadj 0.92, 95%CI: 0.88–0.95 for aged >80 years). Inverse association between DDS and mortality was also found in the underweight older population (HRadj 0.95, 95%CI: 0.90–0.99). A positive association was found between DDS and mortality in the overweight/obese group (HRadj 1.03, 95%CI: 1.00–1.05). However, the interaction between the DDS with sex to mortality was not statistically significant. Conclusion: Increasing DD reduces mortality among Thai older people, especially in those above 70, and underweight. In contrast, an increase in DD also meant an increase in mortality among the overweight/obese group. Focus should be placed on the nutritional interventions aimed to improve DD for those 70 and over and underweight to reduce mortality.