Two-Year Results From a Multi-Site Randomized Trial of a Commercial Weight Loss Program

Abstract

Commercial weight loss programs may contribute to efforts to reduce the prevalence of obesity, although evidence of efficacy and effects on metabolic and cardiovascular risk factors is critical in evaluating the likelihood of sustained benefits. The Jenny Craig (JC) program involves individualized diet and exercise counseling (provided either in-person at community-based sites or by telephone), prepackaged foods and a low-energy density diet. The aims of this study are (1) To test, in a multi-site randomized controlled trial, whether the JC Centre-based and/or JC Direct (telephone-based) interventions promote greater weight loss and maintenance of that loss in overweight or obese women over a 24-month period compared to usual care (UC) conditions; and (2) To describe the effect of the program (vs. UC conditions) on selected biochemical factors, cardiopulmonary fitness, quality of life (QOL) and eating attitudes and behaviors. At randomization, participants (n=442) were 44(10) (mean[SD]) yrs, with BMI 33.8(3.4) kg/m2, weight 92.1(10.7) kg, and waist circumference 108.6(9.6) cm. Two-year data are available for 91% of study participants (n=406), and weight loss is - 8.1(8.6), -6.7(9.3), and -2.2(7.4) kg for the JC Centre- based, JC Direct, and UC groups, an average weight reduction of -8.7%, -7.3%, and -2.4% of initial weight, respectively. The proportion of women at highest risk (CRP>3 mg/L) in the JC arms decreased significantly from 53% at enrollment to 33% at two years, but was unchanged in the UC arm. Interim analysis also shows the JC intervention to promote favorable changes in lipid, leptin and carotenoid levels, and improved cardiopulmonary fitness