• Serum estrone concentrations as measured by radioimmunoassay at 12 months [ Designated as safety issue: No ]
  

• Serum estradiol and free estradiol concentration as measured by radioimmunoassay at 12 months [ Designated as safety issue: No ]
  
• Testosterone and free testosterone as measured at 12 months [ Designated as safety issue: No ]
  
• Sex hormone binding globulin as measured at 12 months [ Designated as safety issue: No ]
  
• Insulin and insulin-like growth factor (IGF)-1 as measured at 12 months [ Designated as safety issue: No ]
  
• IGF binding protein-3 as measured at 12 months [ Designated as safety issue: No ]
  
• Mammographic density (i.e., percentage density and dense area) as measured at 12 months [ Designated as safety issue: No ]
  
• Weight and body mass index as measured at 12 months [ Designated as safety issue: No ]
  
• Total and percentage body fat and body fat distribution (i.e., waist and hip circumferences) as measured by dual x-ray absorptiometry at 12 months [ Designated as safety issue: No ]
  
• Quality of life as measured at baseline, 6 months, and 12 months [ Designated as safety issue: No ]
  
• Change in daily caloric intake as measured by Food Frequency Questionnaire at baseline, 6 months, and 12 months [ Designated as safety issue: No ]
  

OBJECTIVES:

Primary

• Compare the effects of a 1-year exercise intervention, reduced-calorie diet intervention, or a combined exercise and reduced-calorie diet intervention vs no intervention on serum estrone concentrations in overweight or obese postmenopausal women.

Secondary

• Compare the effects of these interventions on serum estradiol and free estradiol in these participants.
• Compare the effects of these interventions on serum testosterone and free testosterone in these participants.
• Compare the effects of these interventions on sex hormone binding globulin in these participants.
• Compare the effects of these interventions on insulin in these participants.
• Compare the effects of these interventions on insulin-like growth factor (IGF)-1 and IGF binding protein-3 in these participants.
• Compare the effects of these interventions on mammographic density in these participants.
• Compare the effects of these interventions on anthropometrics and body composition (i.e., weight, body mass index, total and percentage body fat, and waist and hip circumferences) in these participants.
• Compare the effects of these interventions on quality of life in these participants.

OUTLINE: This is a randomized study. Participants are stratified according to body mass index (< 27 vs ≥ 27).

Participants are randomized to 1 of 4 intervention arms.

• Arm I (exercise program): Participants exercise 3 days per week under the supervision of a physiologist and 2 days per week independently at home, for a total of 5 exercise sessions (at least 45 minutes of moderate-intensity exercise per session) weekly over 12 months.
• Arm II (reduced-calorie diet): Participants meet with a nutritionist individually and in small groups.

Participants receive general information about diet and behavior strategies such as self-monitoring, goal-setting, stimulus-control, problem-solving, and relapse-prevention training. Participants learn to set a calorie goal and a fat gram goal and how to achieve the goal calorie reduction. Meetings are held weekly during the first 6 months of the diet program but taper off over the course of the study.

• Arm III (exercise program and reduced-calorie diet): Participants meet with a physiologist and a nutritionist, as in arms I and II, and exercise and diet accordingly.
• Arm IV (control: delayed diet and exercise): Participants receive study materials on healthy diet and exercise at the end of the 12-month study period. In addition, participants are offered 2 months of group exercise training with a study physiologist and 4 group meetings with a nutritionist to learn about weight loss techniques and behavioral principles for achieving weight loss. All participants undergo testing at baseline and periodically during study. Participants undergo blood collection for evaluation of serum levels of sex and metabolic hormones (i.e., estrone, estradiol, testosterone, free testosterone, sex hormone binding globulin, insulin, insulin-like growth factor [IGF]-1, and IGF binding protein-3) by radioimmunoassay and other immunoassays. Participants also undergo anthropometrics and body composition measurements and mammographic density assessment.

Participants complete questionnaires at baseline and at 6 and 12 months for assessment of diet and exercise.

Quality of life (QOL) is measured at baseline and at 6 and 12 months using the Medical Outcomes Study 36-Item Short Form and the Impact of Weight on QOL questionnaire. Information on health habits, medical history, family history of breast cancer, and reproductive and menstrual history is also collected.

PROJECTED ACCRUAL: A total of 503 participants (135 per intervention arm and 98 in control arm) will be accrued for this study.