OBJECTIVETo analyze the relations of body mass index(BMI)and obese prevalence in differently aged women and explore the effective strategy for preventing obesity among adult Chinese women.

METHODThis study was based on the data from 2002 National Nutrition and Health Survey. The method of multi-steps cluster sampling was adopted. Total subjects including unmarried women (n = 2474), married women without the experience of childbearing (n = 10,816), and married and bearing-child women (n = 4103), were 17,393.

RESULTSIn urban areas, the average body weights of unmarried, married and without childbearing experience, and the married with born-child were (53.7 +/- 9.0) kg, (57.6 +/- 9.4) kg and (54.5 +/- 8.5) kg respectively; the body weights of unmarried, married and without childbearing experience were significantly higher than that of the married with born-child women (t = 12.25, P < 0.001; t = 8.32, P < 0.001); the BMIs of unmarried, married without childbearing experience, and the married with born-child women were (21.1 +/- 3.3) kg/m(2), (22.8 +/- 3.4) kg/m(2) and (22.0 +/- 2.9) kg/m(2) respectively; the BMIs of married without childbearing experience and married with born-child women were significantly higher than that of unmarried women (t = 14.88, P < 0.001; t = 5.76, P < 0.001). In the rural areas, the body weights of unmarried, married without childbearing experience, and the married with born-child women were (52.3 +/- 7.8) kg, (55.3 +/- 8.6) kg and (52.8 +/- 8.1) kg respectively; the body weights of unmarried, the married with born-child women were significantly higher than that of married without childbearing experience (t = 11.67, P < 0.001; t = 14.15, P < 0.001); the BMIs of unmarried, married without childbearing experience, and the married with born-child women were (21.2 +/- 2.8) kg/m(2), (22.5 +/- 3.1) kg/m(2), and (21.8 +/- 3.0) kg/m(2) respectively; the BMIs of married and the married with born-child were significantly higher than that of unmarried women (t = 13.80, P < 0.001; t = 5.34, P < 0.001). In urban areas, the rate of low body weight of unmarried women (18.1%) was higher than that of married without childbearing experience and married with born-child group (7.3% vs. 9.1%; comparing with married without childbearing experience: chi(2) = 113.69, P < 0.001; comparing with married with born-child: chi(2) = 29.65, P < 0.001); the prevalence of overweight and obesity (32.7%) in married without childbearing was significantly higher than that of unmarried women (14.4%) (chi(2) = 28.257, P < 0.001). In rural areas, the rate of low body weight of unmarried women (12.4%) was higher than that of married without childbearing group (6.7%, chi(2) = 50.040, P < 0.001); however, the prevalence of overweight (22.4%) in the married without childbearing was significantly higher than that of unmarried women (12.3%) (chi(2) = 69.119, P < 0.001) and the married with born-child women (15.4%) (chi(2) = 69.866, P < 0.001). The prevalence of overweight and obesity of the married with born-child women was decreasing with extending time of postpartum in urban and rural areas.

CONCLUSIONWeight retention of married with born-child women was one of the most important factors leading to the obesity in the adulthood. However, more attentions should be paid to the changing trend of body weight in the married without childbearing experience.