Effectiveness of lifestyle interventions for individuals with severe obesity and type 2 diabetes: results from the Look AHEAD trial

Unick JL, Beavers D, Jakicic JM, et al; for the Look AHEAD Research Group.
Diabetes Care. 2011;34(10):2152 2157. 

This overview was created under the auspices of KnowledgePoint360 Group, LLC, and was not associated with funding via an educational grant or a promotional interest. 

This study by Unick and colleagues examined 1-year results from the Action for Health in Diabetes (Look AHEAD) trial, which assessed weight loss, changes in cardiovascular disease risk factors, and compliance with diet and fitness recommendations among overweight/obese subjects stratified by body mass index (BMI). Subjects (N=5,145) were from 16 study centers across the US and met the following criteria: 

  • Aged 45–76 years with type 2 diabetes 
  • A1C ≤11% 
  • BMI ≥25 kg/m2 (≥27 kg/m2 if taking insulin) 
  • Body weight ≤400 lb 
  • BP ≤160 mmHg systolic, ≤100 mmHg diastolic 
  • Triglycerides <600 mg/dL 

BMI categories used for Look AHEAD were as follows: severely obese (BMI ≥40 kg/m2); overweight (BMI 25–<30 kg/m2); class I obese (BMI 30–<35 kg/m2); class II obese (BMI 35–<40 kg/m2).  

Subjects were randomized to intensive lifestyle intervention (ILI) or diabetes support and education (DSE). Analysis of initial study data at Year 1 revealed similar weight loss between the ILI and DSE groups across BMI cutpoints; as such, subsequent Look AHEAD analyses (such as this study) focus exclusively on subjects in the ILI group. The ILI group, designed to induce average 7% weight loss over 1 year across study centers with individual participant goals of ≥10% initial weight loss, included the following parameters: 

  • Strategies to modify eating, exercise behaviors 
    • Months 1–6: 3 weekly group sessions, 1 individual session/month with registered dietician, exercise physiologist, behavioral physiologist 
    • Months 7–12: 2 group sessions, 1 individual session/month 
     
  • Caloric goal 1,200–1,800 kcal/day; <30% of calories from fat 
  • Replace 2 meals, 1 snack/day with meal replacement product for months 1–4; one meal, 1 snack/day for months 5–12 

Those in the DSE group attended four meetings during Year 1 and followed general recommendations related to healthy eating and physical activity. 

Subjects were assessed at baseline and 1 year. Treatment adherence was assessed via attendance at group and individual treatment sessions, and self-report of meal replacement use. Results at 1 year: 

  • Changes in body weight (in kg) across BMI groups (N=2,475; P<0.01 for mean across groups): 
    • Overall: -8.71 (7.6) 
    • Overweight: -5.97 (4.7) 
    • Class I: -8.10 (6.2) 
    • Class II: -9.09 (8.0) 
    • Severely obese: -11.2 (9.7) 
     
  • Percent changes in fitness across BMI groups (N=2,256; P<0.03 for mean across groups): 
    • Overall: 20.9 (29.1) 
    • Overweight: 18.3 (19.6) 
    • Class I: 19.6 (28.1) 
    • Class II: 21.3 (29.4) 
    • Severely obese: 24.4 (30.1) 
     
  • Subjects in all BMI categories demonstrated favorable improvements in lipids, BP, and glycemic control. 
  • With the exception of HDL-C, which showed a smaller level of improvement in severely obese subjects vs other BMI groups (P<0.01), similar levels of improvement were observed for A1C, systolic and diastolic BP, fasting glucose, LDL-C, and triglycerides between groups (P>0.05). 
  • Levels of physical activity, program attendance, and use of meal replacements were similar across BMI groups. 

This overview was created under the auspices of KnowledgePoint360 Group, LLC, and was not associated with funding via an educational grant or a promotional interest. 

 

Last Modified: 1/9/2013