The Look AHEAD Study: A Description of the Lifestyle Intervention and the Evidence Supporting It

摘要

The Look AHEAD (Action for Health in Diabetes) study is a multi-center, randomized controlled trial, designed to determine whether intentional weight loss reduces cardiovascular morbidity and mortality in overweight individuals with type 2 diabetes. The study began in 2001 and is scheduled to conclude in 2012. A total of 5,145 participants, with a mean age of 60 years and body mass index of 36.0 kg/m², have been randomly assigned to a lifestyle intervention or to enhanced usual care condition (i.e., Diabetes Support and Education). This article describes the lifestyle intervention and the empirical evidence to support it. The two principal intervention goals are to induce a mean loss ≥ 7% of initial weight and to increase participants’ moderately-intense physical activity to ≥ 175 minutes a week. For the first 6 months, participants attend one individual and three group sessions per month and are encouraged to replace two meals and one snack a day with liquid shakes and meal bars. From months 7−12, they attend one individual and two group meetings per month and continue to replace one meal per day (which is recommended for the duration of the program). Starting at month 7, more intensive behavioral interventions, as well as weight loss medication, are available from a toolbox, designed to help participants with limited weight loss. In years 2−4, treatment is provided mainly on an individual basis and includes at least one on-site visit per month and a second contact by telephone, mail, or e-mail. Short-term (6−8 weeks) refresher groups and motivational campaigns also are offered three times yearly to help participants reverse small weight gains. After year 4, participants are offered monthly individual visits, as well as one refresher group and one campaign a year. The intervention is delivered by a multi-disciplinary team that includes medical staff who monitor participants at risk of hypoglycemic episodes. The study's evidence-based protocol should be of use to researchers, as well as to practitioners who care for overweight individuals with type 2 diabetes.