Abstract Aim of the work: The aim of this work was based on a questionnaire survey to find out the respondents' views on whether smoking cigarettes, electronic cigarettes and the use of heated tobacco affects body weight, including gender differences. The secondary aim was determined with any likelihood of replacing respondents who vape EC or use heated tobacco according to a variable flavor, food, or snack of EC or heated tobacco. Methods: An anonymous online questionnaire consisting of 18 questions was spreaded via Facebook in the Spolucestování, Kolej 17. listopadů and 1. LF UK Nutriční terapeuti interest groups from 21 April 2021 to 31 March 2021, as well as through the discussion forums of the eMimino and Mamaguru websites. Only individuals who smoke cigarettes, vape electronic cigarettes with nicotine or use heated tobacco could participate in the questionnaire survey. The questionnaire was completed by 190 respondents. , while 6 respondents were excluded due to incomplete answers or failure to meet the entry criteria. The final set includes 184 respondents. Results: The group of 184 respondents consisted of 101 women and 83 men. Average age of the group was 27.63 ± 8.20 years, average age of women 27.10 ± 7.53 years, average age of men 28.27 ± 8.96 years. The result shows that 34% of...