The Long-Term Effectiveness of a Lifestyle Intervention in Severely Obese Individuals

Study Questions:

Is an intensive lifestyle intervention effective for weight loss and modification of cardiovascular risk factors among severely obese adults?

Methods:

Data from the Look AHEAD trial were used for the present analysis. This trial included adults from 16 centers. Participants had type 2 diabetes, were between the ages of 45 and 76 years old, and had a body mass index (BMI) ≥25 kg/m2 (or ≥27 kg/m2 if taking insulin). Potential subjects passed a maximal exercise test at baseline and completed 2 weeks of self-monitoring to demonstrate behavioral adherence. Further inclusion criteria were glycated hemoglobin (HbA1c) ≤11%, triglycerides <600 mg/dl, and systolic and diastolic blood pressure <160 and ≤100 mm Hg, respectively. Subjects were randomized to an intensive lifestyle intervention or diabetes support and education. The lifestyle intervention group received a behavioral weight loss program that included group and individual meetings, a ≥10% weight loss goal, calorie restriction, and increased physical activity. Diabetes support and education received a less intense educational intervention. Primary outcomes were 4-year changes in body weight and cardiovascular disease risk factors.

Results:

A total of 5,145 subjects were included in this study. Severely obese participants were younger, had lower physical activity and fitness, a larger proportion were female, and a similar percentage were classified as being non-Hispanic white (64.1%), compared with those with a BMI <40 kg/m2. Outcome assessments were completed in ≥95% of participants in each BMI category at year 4. Across BMI categories, 4-year changes in body weight were significantly greater in participants randomized to the intensive lifestyle arm compared with diabetes support and education (p = 0.05). At year 4, severely obese lifestyle participants lost 4.9% ± 8.5%, which was similar to class I (4.8% ± 7.2%) and class II obese participants (4.4% ± 7.6%), and significantly greater than overweight participants (3.4% ± 7.0%; p < 0.05). Four-year changes in low-density lipoprotein cholesterol, triglycerides, diastolic blood pressure, HbA1c, and blood glucose were similar across BMI categories in lifestyle participants; however, the severely obese had less favorable improvements in high-density lipoprotein cholesterol (3.1 ± 0.4 mg/dl) and systolic blood pressure (-1.4 ± 0.7 mm Hg) compared with the less obese (p = 0.05).

Conclusions:

The investigators concluded that lifestyle interventions can result in important long-term weight loss and improvements in cardiovascular disease risk factors among a significant proportion of severely obese individuals.

Perspective:

These data suggest that lifestyle modification can result in significant benefits (i.e., weight loss and modification of cardiovascular risk factors). However, this intensive intervention may be difficult to replicate in the general health care provider’s office. Cost analysis of such interventions would need to be studied.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Lipid Metabolism, Nonstatins, Diet

Keywords: Insulin, Life Style, Overweight, Diabetes Mellitus, Type 2, Risk Factors, Blood Pressure, Diet, Reducing, Hispanic Americans, Hemoglobin A, Glycosylated, Cholesterol, Body Mass Index, Weight Reduction Programs, Blood Glucose, Cardiovascular Diseases, Obesity, Triglycerides, Diabetes Mellitus, Exercise Test


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