Introduction: According to a report from the European Association for the Study of Obesity (EASO), there are 200 million overweight and obese school children in the world today. To assess body mass for students in Poland, in middle schools, high schools and universities, according to growth charts and BMI. Also, to investigate the link between chosen dietary habits and the risks to these subjects of being overweight and obese. Material and methods: The 13,566 subjects surveyed in 2011 consisted of middle school (3,548), high school (4,423) and university (5,595) students. The two younger groups received a questionnaire that had been devised by GIS (Poland's Chief Sanitary Inspectorate) based on one previously used for the WHO's global school-based student health survey (GSHS). An electronic questionnaire was used for the university students, made available at a designated internet site. Results: Overweight rates of 13%, 11% and 14% were found in students from middle-school, high-school and university. Overall obesity rates were 3%. Most subject ate three meals daily, although almost 1 in 5 said they ate only 1 to 2 meals daily. Snacking between meals was admitted by 84%, 89% and 89% of students, respectively, whereas corresponding rates for nighttime eating were 24%, 37% and 36%. Conclusions: The survey demonstrated that overweight status, according to growth charts and BMI, occurs in 13%, 11% and 14% of subjects in each student group, respectively. Overall, obesity accounts for 3% of respondents. Numerous instances of abnormal dietary habits were found, highlighted by irregular mealtimes, between-meal snacking and nighttime eating.