1. ¹Department of Medicine, Division of Clinical Epidemiology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
2. ²Department of Epidemiology, Medical University of South Carolina, Charleston, South Carolina, USA

Correspondence: Sharon P. Fowler (fowlers@uthscsa.edu)

Received 18 August 2006; Accepted 23 February 2008; Published online 5 June 2008.

Abstract

We have examined the relationship between artificially sweetened beverage (ASB) consumption and long-term weight gain in the San Antonio Heart Study. From 1979 to 1988, height, weight, and ASB consumption were measured among 5,158 adult residents of San Antonio, Texas. Seven to eight years later, 3,682 participants (74% of survivors) were re-examined. Outcome measures were incidence of overweight/obesity (OW/OB_inc) and obesity (OB_inc) (BMI 25 and 30 kg/m², respectively), and BMI change by follow-up (BMI, kg/m²). A significant positive dose–response relationship emerged between baseline ASB consumption and all outcome measures, adjusted for baseline BMI and demographic/behavioral characteristics. Consuming >21 ASBs/week (vs. none) was associated with almost-doubled risk of OW/OB (odds ratio (OR) = 1.93, P = 0.007) among 1,250 baseline normal-weight (NW) individuals, and doubled risk of obesity (OR = 2.03, P = 0.0005) among 2,571 individuals with baseline BMIs <30 kg/m². Compared with nonusers (+1.01 kg/m²), BMIs were significantly higher for ASB quartiles 2–4: +1.46 (P = 0.003), +1.50 (P = 0.002), and +1.78 kg/m² (P < 0.0001), respectively. Overall, adjusted BMIs were 47% greater among artificial sweetner (AS) users than nonusers (+1.48 kg/m² vs. +1.01 kg/m², respectively, P < 0.0001). In separate analyses—stratified by gender; ethnicity; baseline weight category, dieting, or diabetes status; or exercise-change category—BMIs were consistently greater among AS users. These differences, though not significant among exercise increasers, or those with baseline diabetes or BMI >30 kg/m² (P = 0.069), were significant in all 13 remaining strata. These findings raise the question whether AS use might be fueling—rather than fighting—our escalating obesity epidemic.