One-year weight losses in the Look AHEAD study: factors associated with success

Abstract

This report provides a further analysis of the first year weight losses in the Look AHEAD (Action for Health in Diabetes) study and identifies factors associated with success. Participants were a total of 5,145 men and women with type 2 diabetes who were recruited at 16 sites and randomly assigned to an intensive lifestyle intervention (ILI) or a control condition, Diabetes Support and Education (DSE). During year 1, participants in ILI received comprehensive diet and physical activity counseling in a total of 42 group and individual sessions, compared with three educational sessions for DSE participants. As reported previously, at the end of the year, ILI participants lost 8.6% of initial weight, compared to 0.7% for DSE (P < 0.001). Within the ILI group, all racial/ethnic groups achieved clinically significant weight losses (>5.5%), although there were significant differences among groups. For the year, ILI participants attended an average of 35.4 treatment sessions and reported exercising a mean of 136.6 min/week and consuming a total of 360.9 meal replacement products. Greater self-reported physical activity was the strongest correlate of weight loss, followed by treatment attendance and consumption of meal replacements. The use of orlistat, during the second half of the year, increased weight loss only marginally in those ILI participants who had lost <5% of initial weight during the first 6 months and chose to take the medication thereafter as a toolbox option. The lifestyle intervention was clinically effective in all subsets of an ethnically and demographically diverse population.

Figure 1

Percentage of participants in the intensive lifestyle intervention (ILI) and Diabetes Support and Education (DSE) groups that met different weight loss criteria.

Figure 2

Percentage reduction in initial weight (in the ILI group) based on ethnicity and gender.

Figure 3

Percentage reduction in initial weight at 1 year based on quartile of percentage of possible visits attended. The number within each bar shows the mean percentage of visits attended for that quartile.

Figure 4

Percentage reduction in initial weight at 1 year based on quartile of average weekly minutes of self-reported physical activity. The number within each bar shows the mean number of weekly minutes of physical activity.

Figure 5

Percentage reduction in initial weight at 1 year based on quartile of meal replacement products (MR) used. The number within each bar shows the mean number of products used in that quartile.

Figure 6

Percentage reduction in initial weight (in the ILI group) for individuals who did and did not receive orlistat after month 6. Individuals who had lost < 5% of initial weight at month 6 were encouraged to use the medication. Those who had lost 5.0 to 9.9% were allowed to use orlistat upon request. For participants who had lost ≥ 10% at month 6, only those who had regained 2 percentage points or more above their lowest weight were allowed to use medication. (Participants were not randomized to treatment conditions.)