Introduction: One of the major nutritional mistakes committed by children and adolescents is snacking between meals. Sweet or salty snacks are rich in simple sugars, fats, preservatives and dyes, and poor in minerals and vitamins. Their excessive consumption can lead to the development of diet-related diseases in the future. Purpose: To evaluate the nutrition of children and adolescents with a focus on snacking between meals. Materials and methods: The study included 162 students from Bialystok schools, of which primary school students accounted for 30.2%, junior high school 38.3%, high school 31.5%. The questionnaire used by the authors contained 27 questions. Results: Regular meals were consumed by only 55.1% of primary school students, 35.5% of junior high school, and 37.3% of high school students. Two and fewer meals a day were consumed by 1.6% to 5.8% of the students studied. First breakfast was omitted by 18.4% of the students in elementary school, 16.1% of junior high school, and 15.7% of high school. Second breakfast was omitted by 12.9% to 17.6% of the respondents.Sweet products instead of a second breakfast were consumed by 44.9% of primary school students, 61.3% of junior high school, and 64.7% of high school students. Snacking most often occurred in the respondents' home (69.4% of elementary school students, 43.5% of secondary level students, and 52.9% of high school students). Water in school was drunk by 85.7% of primary level students, 56.5% of junior high school, and 51.0% of high school. The main source of knowledge about nutrition for 61.2% of primary level students was the family, while television, radio, and the Internet were the main sources of knowledge for 62.7% of high school students. Conclusions: The regularity of eating in the study group decreased with the studied students’ age. The most popular products in the group of younger students were salty snacks and sweets. Healthy snacking was observed more frequently in the group of high school students. The main place of snacking was the home. The primary source of knowledge about nutrition for primary school students was the family and for high school students the mass media.