The problem raised in the study relates to the eating habits of students and their relations with the body mass index (BMI). The effect of selected sociodemographic variables (sex, place of residence, material status, field of study) on eating habits of the respondents was also analysed. The structure of the Dietary Behaviour Index (DBI) was proposed and its relations to the BMI were established.Material and methods. The study covered 508 students of state and private universities in Poznań (Poland) of whom 73% were female and 27% male. The study used an anonymous questionnaire poll on the basic dietary habits developed on the basis of the Food Pyramid guidelines as well as the Golden Charter of Correct Nutrition. The BMI was calculated on the students’ self-reported weight and height.Results. 15% of the participating students are overweight or obese. The distribution of the BMI differs between men and women (p<.000). Particularly unfavourable behaviour was noted in terms of the consumption of legumes (72% of respondents), fish (53%), dairy products (36%), vegetables (29%) and fruit (27%). Beneficial trends relate to the everyday consumption of breakfast (63%), the number of meals per day (59%), limiting the consumption of red meat (59%), including vegetable fats in the daily diet (56%). The difference in the way of eating described by the DBI is related to the field of study (p<.001) as physical education students had the best indicators.Conclusions. In the studied group of students overweight and obesity are not as frequent as in other countries of Western Europe or America. We noted a number of dietary mistakes made by the respondents, which can lead to adverse health consequences in the future. During the university studies, not only in the fields related to health, information promoting pro-health lifestyle should appear more often