Cancer is the leading cause of death in North Carolina (NC); over 17,400 deaths were attributable to cancer in 2009. Obesity is also a widespread problem; 65% of NC adults were overweight or obese in 2009. Obesity has been linked to risk of several cancers, most notably breast and colon cancer, and also to decreased survival rates. Thus, due to the prevalence and linkage of obesity to major cancers, helping adults to lose weight is necessary to reduce cancer burden statewide.

Fortunately, modest weight losses of only 5 to 10 percent of total body weight have been shown to improve health and are achievable with behavioral lifestyle modification programs, considered the "gold standard" intervention. To date, weight loss via lifestyle modification has been shown to be more effective, and more cost-effective, than pharmaceutical intervention for reducing risk of chronic disease. However, these "gold standard" programs are very time and resource intensive; involving weekly face-to-face (F2F) sessions with groups of 10-20 participants for, at minimum, 16-24 weeks followed by bi-weekly contacts for up to 2 years. To combat this problem investigators, including those from this investigative team, have explored using the Internet to deliver weight loss programs. Internet programs are modestly effective producing 4-7% weight loss (at 6 months) or roughly ½ of what intensive F2F programs can achieve. Internet programs that involve substantial human contact via e-mail produce the best outcomes, yet limit dissemination, and those that involve only automated feedback suffer from low utilization over time. What may be optimal is a hybrid model involving fewer F2F visits coupled with an Internet program. We are currently investigating an alternative F2F approach whereby participants attend F2F visits once per month, as phase 1 of a 6-step, stepped care approach to treating obesity (R01 HL084400). The initial results are promising; at 3 months weight losses did not differ significantly between the monthly F2F approach and weekly F2F approach (-15.23 + 10.22 lbs. weekly vs. -12.32 + 10.26 lbs. monthly; p\>.05). While the monthly program is ¼ of the visits of the standard treatment approach, the group size of 20 still severely limits dissemination. Delivering this monthly F2F approach in much larger groups (approximately 200 or more), coupled with an Internet program between sessions, may represent an effective and disseminable approach for achieving weight loss in NC communities.

A standard behavioral intervention based on the DPP and Premier trials will be adapted for this protocol. Behavioral weight control approaches are founded on teaching skills and providing the support necessary to enable participants to adopt lower calorie diets (e.g., 1500-2000 kcals per day based on starting weight) and moderate physical activity (e.g., walking) to produce energy deficits necessary to produce modest weight losses of 1-2 lbs per week. Based on findings from the focus groups and review of study design and expectations from the funding source to conduct pilot research that will lead to future funding and publishable findings, the main intervention has been finalized (since initial IRB submission). The intervention will consist of randomization to either Large Group + Internet or Small Group + Internet interventions. The main difference between the two study groups will be the size of the monthly group sessions. The internet program delivered in between monthly group sessions will be identical. Group sessions will occur at the Nutrition Research Institute (NRI) on a monthly basis in months 1 - 4. The internet program will be used between group sessions. The monthly sessions will begin with an individual, private, weigh-in, followed by a group session. One treatment arm will have large group sessions with interactive features and audience participation. The large groups will be comprised of approx. 125 participants, last approximately 1 hour, and be facilitated by a weight loss expert (dietitian, psychologist, exercise physiologist). The other treatment arm will have small group sessions and will consist of approx. 25 participants and will follow traditional behavioral weight control group session protocol with facilitation by the above named-experts. Participants will be encouraged to enroll in the study with up to two friend or family member support partners who are also meet eligibility criteria. Support partners will be randomized to the same treatment arm. The F2F sessions are coupled with a comprehensive Internet program tested previously by Tate et al that provides the self-monitoring tools, tailored automated behavioral feedback, tailored lifestyle content (lessons) resources, and social support (e.g. online message board) that participants will be encouraged to use in between monthly sessions.