Does Lifestyle Intervention Improve Health of Adults with Overweight/Obesity and Type 2 Diabetes? Findings from the Look AHEAD Randomized Trial

Abstract

This paper reviews the main findings from the Action for Health in Diabetes (Look AHEAD) Trial, a randomized trial testing the long-term health effects of intensive lifestyle interventions (ILIs) in 5,145 persons with overweight/obesity and type 2 diabetes. Although the primary outcome originally focused on cardiovascular morbidity and mortality, secondary outcomes included a broad range of health parameters related to diabetes and obesity. As the cohort aged, study outcomes were expanded to include health problems affecting geriatric populations, such as cognitive impairment and disability.This review summarizes the history of this trial and presents findings related to a wide range of health outcomes. Studies are reviewed that showed positive impact of ILI on diabetes control and complications, depression, physical health-related quality of life, sleep apnea, incontinence, brain structure, and health care use and costs. Several composite indices were also positively impacted by ILI, including multimorbidity, geriatric syndromes, and disability-free life years. However, there are also some important outcomes that did not show significant differences between the intervention and control, including cardiovascular morbidity and mortality, cancer, cognitive function, and cognitive impairment; for several of these nonsignificant effects, post hoc analyses suggested that there may be differences among subgroups, raising the possibility that ILI may be beneficial to some but potentially harmful to others. The only adverse effects of ILI relative to diabetes support and education were on frailty fractures and the related negative effects on body composition and bone density. Through this review, the manuscript seeks to determine whether weight loss should be encouraged in this population; given the large number of beneficial effects, relative to the small number of adverse effects, the answer appears to be yes.

Trial registration: ClinicalTrials.gov NCT00017953.