Diet Soda Intake Is Associated with Long-Term Increases in Waist Circumference in a Biethnic Cohort of Older Adults: The San Antonio Longitudinal Study of Aging.

Objectives To examine the relationship between diet soda ( DS) intake ( DSI) and long-term waist circumference ( WC) change (Δ WC) in the biethnic San Antonio Longitudinal Study of Aging ( SALSA). Design Prospective cohort study. Setting San Antonio, Texas, neighborhoods. Participants SALSA examined 749 Mexican-American and European-American individuals aged 65 and older at baseline (baseline, 1992-96); 474 (79.1%) survivors completed follow-up 1 ( FU1, 2000-01), 413 (73.4%) completed FU2 (2001-03), and 375 (71.0%) completed FU3 (2003-04). Participants completed a mean of 2.64 follow-up intervals, for 9.4 total follow-up years. Measurements DSI, WC, height, and weight were measured at outset and at the conclusion of each interval: baseline, FU1, FU2, and FU3. Results Adjusted for initial WC, demographic characteristics, physical activity, diabetes mellitus, and smoking, mean interval Δ WC of DS users (2.11 cm, 95% confidence interval ( CI) = 1.45-2.76 cm) was almost triple that of nonusers (0.77 cm, 95% CI = 0.29-1.23 cm) ( P < .001). Adjusted interval Δ WCs were 0.77 cm (95% CI = 0.29-1.23 cm) for nonusers, 1.76 cm (95% CI = 0.96-2.57 cm) for occasional users, and 3.04 cm (95% CI = 1.82-4.26 cm) for daily users ( P = .002 for trend). This translates to Δ WCs of 0.80 inches for nonusers, 1.83 inches for occasional users, and 3.16 for daily users over the total SALSA follow-up. In subanalyses stratified for selected covariates, Δ WC point estimates were consistently higher in DS users. Conclusion In a striking dose-response relationship, increasing DSI was associated with escalating abdominal obesity, a potential pathway for cardiometabolic risk in this aging population. [ABSTRACT FROM AUTHOR]