A Multi-Site Randomized Trial of a Commercial Weight Loss Program

The first study aim is to test, in a randomized controlled trial, whether participation in the multifaceted traditional center-based commercial weight loss intervention program and/or the telephone-delivered commerical program is associated with a greater degree of weight loss at six, 12, and 18 months and whether weight loss is maintained over a 24-month period in overweight or obese women, compared to usual care or control conditions. This study utilizes a randomized study design with subjects assigned to the center-based weight loss program, telephone-delivered program, or a usual care control group. The second study aim is to describe the effect of participation in the weight loss programs (versus control conditions) on circulating lipids (fasting total plasma cholesterol and triglycerides, low-density lipoprotein [LDL] cholesterol, and high-density lipoprotein [HDL] cholesterol), carotenoids (a biomarker of vegetable and fruit intake), insulin, glucose, leptin, C-reactive protein, and vitamin D, and cardiopulmonary fitness. The center-based intervention involves in-person counseling and obtaining food items from the center, whereas the telephone-delivered program involves telephone counseling with food delivered to the home every two weeks.

Secondary aims of this study involve describing the characteristics associated with greater weight loss and maintenance in each of the two intervention arms. The hypothesis to be tested is that selected participant characteristics, such as older or younger age, might be differentially associated with greater success across the two types of programs and approaches.

Notably, the results of this study would contribute valuable data to the scientific knowledge base regarding the various modalities of communication for behavioral interventions (in-person versus telephone counseling). This is an important issue currently being considered and debated among clinical and community-based behavioral and nutritional scientists whose intervention efforts focus on promoting behavior change and positive effects on health-related outcomes such as weight reduction.