The purpose of this study is to determine the effect of menopause on obesity, energy balance, and insulin in postmenopausal, obese women.

The effect of menopause on body composition and cardiovascular risk in healthy caucasian women has been the subject of much study. In contrast, there are few data available on menopause in African-American women. Since menopause is associated with potentially preventable health risks in women, this proposal is aimed at characterizing the perimenopausal period in terms of body fat, energy balance, and insulin action in both caucasian and African-American women.

The study will address 4 general hypotheses:

• Menopause increases both total and visceral abdominal fat
• Changes in body composition and body weight at menopause are mediated, at least in part by changes in 24-hour energy expenditure and/or food intake
• Menopause results in decreased insulin sensitivity that may predispose certain women to develop diabetes later in life
• African-American women may respond to the shifts in reproductive hormones at menopause differently than caucasian women.

Inclusion Criteria:

• Age 47-52 yr, at time of enrollment
• Body Mass Index 25-40
• Normal oral glucose tolerance test by National Diabetes Data Group criteria
• Premenopausal, defined by FSH levels <30mIU/ml and at least 5 menstrual periods in the last 6 months
• Able to confirm ethnic heritage of past 2 generations in family

Exclusion Criteria:

• hypertension or hypercholesterolemia requiring medication
• regular use of medications that influence glucose tolerance
• use of oral contraceptives within the past 6 months
• history of myocardial infarction or significant coronary vascular disease or stroke
• history of endocrine, kidney, or liver disease or malignancy
• any psychopathology, including eating disorders, substance abuse, and major depression
• unable to complete longitudinal study commitment, including anticipating moving out of the area within the next 5 years.

Pennington Biomedical Research Center is located in Baton Rouge, Louisiana, adjacent to the medical services district of the Regional Medical Center. The city of Baton Rouge is the home of state government, the 27,000-student Louisiana State University, the 9,000-student Southern University and a large petrochemical industry. Lacking the traditional active urban "downtown", the region is characterized by the suburban pattern of single family subdivisions and small apartment complexes. The population within a 7 parish (i.e. county) area is 635,202. The population of East Baton Rouge Parish is 380,105 with an ethnic distribution of 62% Caucasian, 35% African-American, 1% Asian, and <1% Native American and Hispanic. There are 34,885 people over age 65 and 251,586 between ages 16-65 yr.