Eight-year weight losses with an intensive lifestyle intervention: the look AHEAD study

Abstract

Objective: To evaluate 8-year weight losses achieved with intensive lifestyle intervention (ILI) in the Look AHEAD (Action for Health in Diabetes) study.

Design and methods: Look AHEAD assessed the effects of intentional weight loss on cardiovascular morbidity and mortality in 5,145 overweight/obese adults with type 2 diabetes, randomly assigned to ILI or usual care (i.e., diabetes support and education [DSE]). The ILI provided comprehensive behavioral weight loss counseling over 8 years; DSE participants received periodic group education only.

Results: All participants had the opportunity to complete 8 years of intervention before Look AHEAD was halted in September 2012; ≥88% of both groups completed the 8-year outcomes assessment. ILI and DSE participants lost (mean ± SE) 4.7% ± 0.2% and 2.1 ± 0.2% of initial weight, respectively (P < 0.001) at year 8; 50.3% and 35.7%, respectively, lost ≥5% (P < 0.001), and 26.9% and 17.2%, respectively, lost ≥10% (P < 0.001). Across the 8 years ILI participants, compared with DSE, reported greater practice of several key weight-control behaviors. These behaviors also distinguished ILI participants who lost ≥10% and kept it off from those who lost but regained.

Conclusions: Look AHEAD's ILI produced clinically meaningful weight loss (≥5%) at year 8 in 50% of patients with type 2 diabetes and can be used to manage other obesity-related co-morbid conditions.

Trial registration: ClinicalTrials.gov NCT00017953.

Figure 1

Flowchart for screening, randomization, and follow-up of participants. Participants who did not complete outcome assessments in years 1 through 8 had either died, withdrawn from the study, or missed the assessment.

Figure 2

Figure shows mean (±SE) weight losses over 8 years for participants randomly assigned to an intensive lifestyle intervention (ILI) or diabetes support and education (DSE; usual care group). Differences between groups were significant (p<0.001) at all years.

Figure 3

Figure 3(a). Percentage of participants in the ILI and DSE groups who achieved different categorical weight losses at year 1. The percentages are cumulative such that the 68% of ILI participants who lost 5% or more of initial weight includes those who also lost ≥10% and ≥15%. P<0.001 for all comparisons between treatment groups. Figure 3(b). Percentage of participants in the ILI and DSE groups who achieved different categorical weight losses at year 8. The percentages are cumulative as described for Figure 1(A). P<0.001 for all comparisons between treatment groups.

Figure 4

Figure 4(a). Weight loss trajectories over 8 years in 825 participants in the intensive lifestyle intervention (ILI) who, at year 1, lost ≥10% of initial weight and, at year 8, provided a measured body weight. The figure shows the number of participants who, at year 8, maintained a loss of 10% or more of initial weight (N=324), of 5.0–9.9% (N=213), of 0–4.9% (N=171), or who gained above their baseline weight (N=117). The percentages shown in parentheses are based on the sample size for the subgroup. Thus, the 324 of 825 participants who maintained a ≥10% loss at year 8 comprised 39.3% of this subgroup of participants. Figure 4(b). Weight loss trajectories over 8 years in 633 ILI participants who, at year 1, lost 5.0–9.9% of initial weight and, at year 8, provided a measured body weight. The four categories of weight change that these participants achieved at year 8 are presented in the same manner as in Figure 4(A). Figure 4(c). Weight loss trajectories over 8 years in 656 ILI participants who, at year 1, lost <5% of initial weight and, at year 8, provided a measured body weight. The four categories of weight change that these participants achieved at year 8 are presented in the same manner as in Figure 4(A).