Consumption of diet soft drinks (DSDs) has been linked to increased incidence of obesity, metabolic syndrome, and diabetes. The authors examined the relationship between DSD consumption and long-term change in waist circumference (ΔWC) in 474 participants, aged 65-74 yrs at baseline, in the San Antonio Longitudinal Study of Aging (SALSA). Overall, DSD users experienced 70% greater increases in WC compared with non-users.
Measures of height, weight, waist circumference (WC), and DSD intake were recorded at baseline and at each of 3 follow-up exams, for an average follow-up interval of 3.6 yrs (9.5 yrs total). Using repeated-measures ANCOVA, we compared mean ΔWC for DSD users vs. non-users in all follow-up periods, adjusted for sex; baseline WC, age, ethnicity, education, neighborhood, leisure physical activity, diabetes and smoking status; and length of follow-up.
WC is widely used as a proxy measure of visceral adiposity, a major risk factor for diabetes, cardiovascular disease, cancer, and other chronic conditions. These results suggest that – amidst the national drive to reduce consumption of sugar-sweetened drinks – policies which would promote the consumption of DSDs may have unintended deleterious effects. Data from this and other prospective studies suggest that the promotion of diet sodas as healthy alternatives may be ill-advised: they may be free of calories, but not of consequences.