The paper gives the long-term results of five-year correction of unbalanced nutrition (5 and 16 years after its completion) in a population sample of boys aged 12 years or older. Information on nutrition was obtained applying a food frequency questionnaire. Information on their diets was obtained using a food frequency questionnaire. The effect of a prevention intervention was evaluated by comparing the rate of consumption of different foods in two male groups (prevention and comparison groups) aged 22 and 33 years. The results of the study demonstrated that their diets were atherogenic in the majority of adult males in both the prevention and comparison groups. The particularly high incidence of alimentary disorders, such as excessive fat, cholesterol, salt, and alcohol intakes, was established in the young men aged 22 and 33 years. The positive changes found in the dietary patterns of men aged 22 years (lower intake of butter, sausages, and boiled sausages) and those aged 33 years (higher intake of 1.5% milk, shrimps and lower intake of butter and sugar) 5 and 16 years after completion of the prevention intervention may have resulted from the healthy nutrition knowledge got in the period of active prevention intervention at a school age (adolescence).