Beverages and Societal Health

Consumption of sugar sweetened beverages (SSB) has been linked to obesity and, independent of body weight, risk for diabetes and cardiovascular disease. With rising public health awareness of these potential adverse effects, consumption of artificially sweetened beverages (ASB) has increased dramatically. These low-calorie products are marketed as "diet," with the implication that they promote weight loss and improved health. However, there are no long-term experimental studies of ASB and body weight or any other health outcome. Several recent prospective observational studies have linked intake of ASB to increased risk of the metabolic syndrome, type 2 diabetes, and obesity. In the proposed clinical trial, 270 young adults who habitually consume SSB will be randomly assigned to one of three groups: 1) to continue consuming habitual levels of SSB; 2) to substitute ASB for SSB; or 3) to substitute unsweetened beverages for SSB. Each group will receive home delivery of the targeted beverage for 1 year, using methods that build upon previous successful work. Careful attention will be given to assuring treatment fidelity, equivalence of treatment intensity, and avoidance of experimental confounders. The primary study endpoint will be the ratio of serum triglyceride to HDL-cholesterol concentrations. Secondary endpoints will include changes in other cardiovascular disease risk factors, body weight, dietary quality, and taste preferences.

Inclusion criteria

• Aged 18 to 40 years
• Consumption of at least 12 fluid ounces of sugar-sweetened beverage per day
• Willingness to consume types of beverages consistent with group assignment
• Body mass index (BMI) ranging from 18.5 - 40 kg/m2, and body weight ≤275 pounds
• Access to a working telephone or cell phone

Exclusion criteria

• Intention to move away from the greater Boston area during the projected period of study enrollment (i.e., 1 year post-randomization)
• Plans to be away from home for 5 weeks or longer during the study period (e.g., moving away from the greater Boston area during the summer)
• Physician diagnosis of a major medical illness, eating disorder, or phenylketonuria (PKU)
• Chronic use of any medication that may affect one or more study endpoints
• Impaired fasting glucose (IFG, fasting blood glucose ≥110 mg/dL)
• Current moderate or heavy smoker (>10 cigarettes per day)
• Another member of the family (i.e., first degree relative) or household participating in the study If female,
• Pregnant in the past 12 months or planning to become pregnant during the study period
• Lactating in the preceding 3 months
• Change in birth control medication in previous 3 months or plans to change during the study period