Rural Lifestyle Intervention Treatment Effectiveness Trial

Higher rates of obesity, sedentary lifestyle, and coronary heart disease are observed in rural than in non-rural areas of the U.S., yet the treatment of obesity in the rural population has received little attention. Efficacy trials, conducted in academic health centers, show that lifestyle interventions can produce sufficient weight reductions to improve health, but very few trials have been carried out in medically underserved community settings. Moreover, the high intensity of treatments used in efficacy studies represents a barrier to dissemination into rural settings. The existing infrastructure of the United States Department of Agriculture Cooperative Extension Service, with over 2900 offices nationwide, may serve as a valuable resource for bringing lifestyle interventions to rural areas. Preliminary data from our rural obesity research program show promising findings for lifestyle interventions delivered through Extension offices. The next logical step in this line of research is to determine the minimum intensity of treatment required to produce clinically meaningful, long-term weight reductions. We propose to conduct a single-blind, multi-site, randomized controlled trial in obese adults (N=542) to evaluate the effects of LOW, MODERATE, and HIGH doses of lifestyle treatment on two-year changes in body weight, compared to an education CONTROL condition. The LOW intensity condition reflects the dose of group treatment commonly used in community settings, whereas the HIGH dose corresponds to the intensity level employed in efficacy trials. The MODERATE intensity intervention represents a treatment dose that our preliminary data suggest may provide benefits comparable to the HIGH intensity intervention. Our principal hypothesis is that both the MODERATE and HIGH interventions will produce greater weight reductions at two years than either the LOW or CONTROL conditions. We will also evaluate the proportion of participants in each condition, who achieve clinically significant weight losses, and we will examine changes in metabolic risk factors, dietary intake, physical activity, and quality of life. We will calculate the cost-effectiveness of the interventions, and we will investigate potential mediators of long-term change.

Inclusion criteria

• Age: 21 to 75 years
• Body Mass Index: 30 to 45 kg/m**2

Exclusion criteria

• Underlying disease likely to limit lifespan and/or increase risk of interventions:cancer requiring treatment in past five years (exception: non-melanoma skin cancer); serious infectious diseases (e.g., self-reported HIV, self-reported tuberculosis or treatment); myocardial infarction or cerebrovascular accident within the last six months; unstable angina within the past six months; congestive heart failure; chronic hepatitis; cirrhosis; chronic malabsorption syndrome; chronic pancreatitis; irritable bowel syndrome; previous bariatric surgery; history of organ transplantation; history of musculoskeletal conditions that limit walking; chronic lung diseases that limit physical activity; and any other condition likely to limit five-year life expectancy.
• Metabolic exclusions: fasting blood glucose > 125 mg/dl at screening if not known to be diabetic (diabetic patients under active treatment will be enrolled if approved by primary provider); fasting serum triglycerides > 400 mg/dl at screening; resting blood pressure > 140/90 mm Hg.
• Medication exclusions: antipsychotic agents; monoamine oxidase inhibitors; systemic corticosteroids; antibiotics for HIV or Tuberculosis; chemotherapeutic drugs; or use of prescription weight-loss drugs within six months.
• Conditions or behaviors likely to affect the conduct of the trial: unwilling or unable to give informed consent; unable to read English at the 5th grade level; unwilling to accept random assignment; unwilling to travel to Extension office for intervention sessions; participation in another randomized research project; weight loss > 10 pounds in past six months; likely to move out of the county in next two years; major psychiatric disorder; excessive alcohol intake; BMI > 45; prior participation in the TOURS trial; and other conditions which in the opinion of staff would adversely affect participation in the trial