The DIET study: Long-term outcomes of a cognitive-behavioral weight- control intervention in independent-living elders

Objective: To describe the long-term outcomes of a cognitive-behavioral weight-control intervention implemented in a community-based sample of independent-living, older adults. Design: A quasi-experimental design was used to compare an intervention community with a wait-listed control community. Comparisons between the communities were made at 40 weeks (J Am Diet Assoc. 1994;94:37-42). The controlled trial ended at 40 weeks; then both communities received 2 years of intervention. Two-year data from both communities were combined and are presented in this article. Three-year outcome data from the initial intervention community were available and are also presented. Subjects: A total of 247 overweight (>4.5 kg of age-adjusted weight), older (mean age=71 years) adults in 2 independent-living retirement communities participated in the study. Intervention: The Dietary Intervention: Evaluation of Technology (DIET) study consisted of an intensive 10-week psychoeducational approach focused on lifestyle change, followed by a less intensive 2-year phase focusing on relapse prevention and maintenance of lifestyle changes. Outcome measures: Physiologic and behavioral variables were analyzed at baseline and at 2 years after baseline. This article reports the combined 2-year outcome data from both retirement communities. Results of an additional follow-up 1 year after intervention was withdrawn are reported for the initial intervention community. Statistical analysis: A within- subjects repeated measures analysis of variance design was used to test for significant changes in weight and lipid values over time. Results: At 2 years, 70% of those who started the intervention remained actively enrolled. This group showed significant decreases in body mass index (-1.2, P<.001) and glucose level (-0.80 mmol/L, P<.001). Although high-density lipoprotein cholesterol (HDL-C) levels had increased at 40 weeks after baseline, this was not maintained at 2 years. At the 3-year follow-up, changes in body mass index and glucose level were maintained. Applications/conclusions: The purpose of this article was to describe the long-term outcomes of a community-based weight-reduction intervention for older adults. The findings may be of interest to clinicians who design community or worksite weight- reduction programs. Although the intervention was designed to be a low- intensity program, attrition over the length of the study indicates that this intervention was efficacious in maintaining reductions in weight and glucose levels for overweight older adults for 3 years.