Introduction. Overweight is an increasing social problem. Thus, investigating its sources and reasons is of great significance and it arouses not only of researches’ interest. Aim. The aim of the study was to verify: whether rational eating (RE) and psychosocial maturity (PM) – as the aspects of eating maturity (EM) – are associated with BMI and whether there are any differences in the level of EM and BMI with respect to socio-demographic features, including the place of residence. Material and methods. The Questionnaire of Eating Maturity was used to assess RE and PM. The study was conducted on the group of 400 women (living in the city and the village) from 5 Polish voivodeships. Results and conclusions. The average BMI in the studied group was on the standard level. The higher the PM, the lower the BMI (r = -0.19, p < 0.05), and the older the individual, the higher his/her RE (r = 0.12, p < 0.05). There were significant differences in BMI between women on maternity leaves and working mothers (t = 2.11, df = 398, p < 0.05). Women from mazowieckie and pomorskie voivodeships had the highest EM, whereas from lubuskie – the lowest. Women from lubuskie were the youngest and had the lowest RE. The differentiation of EM and BMI results as regards socio-demographic factors indicates that the body weight is a multifactorial issue. Obesity is influenced by psychological as well as socio-demographic features that should not be considered separately.

Key words: eating maturity, BMI, obesity, psychological factors, sociodemographic factors.