The primary objectives of this clinical trial are to determine if replacing sugar sweetened beverages with water consumption promote weight loss over 6 months in overweight adults and if replacing sugar sweetened beverages with water consumption promote greater weight loss over 6 months relative to replacement with other non-caloric sweetened beverages or control.

The secondary objective is to identify mediators and moderators of the effect of water replacement including hydration status, glucose metabolism, anthropometrics, physical activity, dietary intake and resting metabolic rate.

Inclusion Criteria:

• 18-65 years of age.
• Body mass index (BMI) between 25.0-49.9 kg/m2.
• Subject consumes at least 280 calories per day from caloric beverages.

Exclusion Criteria:

• Report losing >5% of current body weight in the previous 6 months.
• Report participating in a research project involving weight loss or physical activity in the previous 6 months, as these proximal experiences may impact the results of this study. Additionally, report current participating in any other research studies whose results could be compromised by or in which participation could compromise this research study. (Participation in a research study that would not affect or be affected by this study is allowed.)
• Report pregnancy or lactation during the previous 6 months, or planned pregnancy in the next 6 months.
• Report taking medication that could affect metabolism or change body weight (e.g., synthroid).
• Report hospitalization for psychiatric problems during the prior year.
• Report major psychiatric diagnoses and organic brain syndromes.
• Report heart problems, chest pain, cancer within the last 5 years
• Being treated by a therapist for psychological issues or problems with psychotropic medications.
• Report behaviors that indicate probable alcohol dependence as assessed by the Rapid Alcohol Problems Screen (RAPS4-QF) (Cherpitel CJ, 2002).
• Unwilling to change intake of beverages during the study period.
• Plan to move from the area during the study period, and/or unable to attend monthly group meetings.
• Report not having adequate transportation to the study center that would allow transport of study supplies back to the subject's home.
• Report not being able to attend group meetings on Monday or Tuesday evenings.