The Look AHEAD study: a description of the lifestyle intervention and the evidence supporting it

Abstract

The Look AHEAD (Action for Health in Diabetes) study is a multicenter, 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 5145 participants have been randomly assigned to a lifestyle intervention or to an 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 >or = 7% of initial weight and to increase participants' moderately intense physical activity to > or =175 min/wk. 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 to 12, they attend one individual and two group meetings per month and continue to replace one meal per day (which is recommended for the study's duration). Starting at month 7, more intensive behavioral interventions and weight loss medication are available from a toolbox, designed to help participants with limited weight loss. In Years 2 to 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. After Year 4, participants are offered monthly individual visits. The intervention is delivered by a multidisciplinary team that includes medical staff who monitor participants at risk of hypoglycemic episodes.

Figures

Figure 1

The figure shows an algorithm used to assist individuals who are not meeting the recommended activity goals. With all treatment algorithms used in Look AHEAD, Level A interventions involve the use of standard methods of care, provided during regular treatment visits. Level B interventions require more detailed assessment and planning and possibly modest financial expenditures. Level C interventions are the most intensive and costly.

Figure 2

The figure presents an algorithm for adjusting the use of medications associated with hypoglycemia. At baseline, medical staff identify all participants in the lifestyle intervention who are prescribed hypoglycemic agents (e.g., insulin, sulfonylurea, repaglinide, and nateglinede) and have them monitor their blood glucose (BG) twice a day for 1 week. Participants are provided with a meter, test strips, and glucose, if needed. BG readings are reviewed with participants at the end of the week, and medications are adjusted, prior to initiating caloric restriction, using the guidelines shown.