Table 1.

Selected characteristics of the study population

Variable
Age, mean (SD), y	52.0 (9.1)
Body mass index at baseline, kg/m2	24.0 (3.4)
Body mass index at age 50, kg/m2	23.5 (3.3)
Body mass index at age 20, kg/m2	19.6 (2.5)
Average adult body mass index, kg/m2	22.6 (2.5)
Education level, %
≤ Elementary school	21.6
Middle school	36.9
High school	27.9
≥ College	13.6
Occupation, %
Professionals, technicians, administrators	28.7
Clerical and service workers	20.8
Manufacturing and agricultural workers	50.6
Annual family income, yuan, %
< 10,000	16.2
10,000 to < 20,000	38.3
20,000 to < 30,000	28.1
≥ 30,000	17.5
Postmenopausal, %	49.6
Hormone therapy, %	2.1
Ever smoked cigarettes, %	2.8
Ever drank alcohol, %	2.2
Regular exercise, mean, hr/wk	2.0 (3.7)