7-YEAR TRENDS IN BODY-WEIGHT AND ASSOCIATIONS WITH LIFE-STYLE AND BEHAVIORAL-CHARACTERISTICS IN BLACK-AND-WHITE YOUNG-ADULTS - THE CARDIA STUDY

Objectives. This study estimated the amount of weight change in a bira cial cohort of young adults and the separate components attributable t o time-related and aging-related changes, as well as identified possib le determinants of weight change. Methods. In this population-based pr ospective study of 18- to 30-year-old African-American and White men a nd women, body weight and prevalence of overweight were measured from 1985/86 to 1992/93. Results. Average weight increased over the 7 years , increases ranging from 5.2 kg (SE = 0.21, n = 811) in White women to 8.5 kg (SE = 0.3, n = 882) in African-American women. Significant tim e-related increases in weight, ranging from 2.0 kg (SE = 1.0) in White women to 4.8 kg (SE = 1.0, n = 711) in African-American men, accounte d for 40% to 60% of the average total weight gain. Aging-related incre ases were also significant, ranging from 2.6 kg (SE = 0.8, n = 944) in White men to 5.0 kg (SE = 1.1) in African-American women. The prevale nce of overweight increased progressively in each group. Decreased phy sical fitness was most strongly associated with weight gain in both se xes. Conclusions. The observed dramatic time-related weight gains, mos t likely due to secular (period-related) trends, are a serious public health concern.