Location: Children's Nutrition Research CenterTitle: Four-year weight losses in the Look AHEAD study: Factors associated with long-term success) Author
Submitted to: Obesity
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/19/2011
Publication Date: 10/19/2011
Citation: Wadden, T.A., Neiberg, R.H., Wing, R.R., Clark, J.M., Delahanty, L.M., Hill, J.O., Krakoff, J., Otto, A., Ryan, D.H., Vitolins, M.Z., and the Look AHEAD Research Group. 2011. Four-year weight losses in the Look AHEAD study: Factors associated with long-term success. Obesity. 19(10):1987-1998. Interpretive Summary: Obesity puts individuals at greater risk for developing conditions such as cardiovascular diseases and type 2 diabetes; however, reductions of 5-10% of body weight can improve risk factors related to these conditions. While there is strong support for the short term effectiveness of weight loss interventions, there is less support for the maintenance of weight loss long term. In fact without follow-up care, obese individuals usually regain one-third of their initial weight loss within a year following treatment, and a return to baseline weight is often observed within 3-5 years. Look AHEAD is a clinical trial which examines the effectiveness of an intensive lifestyle intervention (ILI) for obese individuals with Type 2 diabetes compared to a usual care support group. Previous evaluations of the ILI have found it to be effective in achieving significant weight loss for participants after 1 year. This study examined whether these losses were maintained 4 years later. This study found that the participants who received the ILI achieved a mean weight loss four times greater than their counterparts participating in the usual care education support group. While men lost significantly more weight in the first three years and reported more physical activity and higher daily calorie consumption, the significant difference in weight loss between genders was not observed in year 4. Greater weight loss among the study’s oldest participants for all four years is observed in addition to significantly more treatment sessions in year 1 followed by more treatment contacts in year 2-4 and lower self-reported daily calorie intake, which could be attributable for the oldest participants larger weight loss at year 4. The strongest determinant of achieving a large loss at year 4, was weight loss in year 1. Look AHEAD’s treatment protocol for the first year of intervention may inform practitioners and researchers in improving weight management in overweight/obese patients and is presently being translated into programs feasible in primary care and community settings. With ILI effectively achieving weight loss at year 4, this study provides an exceptional opportunity to examine the effects of weight loss over time. In 2014, Look AHEAD will be completed as the longest, continuously implemented lifestyle intervention for weight management and the first to examine whether weight loss, combined with increased physical activity, results in reductions in cardiovascular morbidity and mortality.
Technical Abstract: This report provides a further analysis of the year 4 weight losses in the Look AHEAD (Action for Health in Diabetes) study and identifies factors associated with long-term success. A total of 5,145 overweight/obese men and women with type 2 diabetes were randomly assigned to an intensive lifestyle intervention (ILI) or a usual care group, referred to as Diabetes Support and Education (DSE). ILI participants were provided approximately weekly group or individual treatment in year 1; continued but less frequent contact was provided in years 2-4. DSE participants received three group educational sessions in all years. As reported previously, at year 4, ILI participants lost an average of 4.7% of initial weight, compared with 1.1% for DSE (P < 0.0001). More ILI than DSE participants lost greater than or equal to 5% (46% vs. 25%, P < 0.0001) and greater than or equal to 10% (23% vs. 10%, P < 0.0001) of initial weight. Within the ILI, achievement of both the 5% and 10% categorical weight losses at year 4 was strongly related to meeting these goals at year 1. A total of 887 participants in ILI lost greater than or equal to 10% at year 1, of whom 374 (42.2%) achieved this loss at year 4. Participants who maintained the loss, compared with those who did not, attended more treatment sessions and reported more favorable physical activity and food intake at year 4. These results provide critical evidence that a comprehensive lifestyle intervention can induce clinically significant weight loss (i.e., greater than or equal to 5%) in overweight/obese participants with type 2 diabetes and maintain this loss in more than 45% of patients at 4 years.