The master thesis deals with issue of dietary fiber. It introduces the readers with basic information about dietary fiber, health benefits associated with increasing intake of dietary fiber, sources of dietary fiber or the recommended daily allowance for different groups of the population. It also describes the individual components of dietary fiber and their basic attributes. The research part is focused on the evaluation of basic knowledge about dietary fiber among high school students of various specializations. Finds out what an overview of the issue, health benefits, food labeling or how often they include fiber containing foods in their diet. Increase knowledge about dietary fiber, health benefits and its sources among high students is the main goal at this project. The specific goal was to increase the consumption of foods rich in dietary fiber.