Purpose The purpose of this study is to evaluate the perception and knowledge of standard food/meal portion size and related factors in young adults. Design/methodology/approach The present study was conducted on 1,000 volunteer young adults, consisting of 504 men and 496 women (18 and 28 years). The portion size of food/meal, amount of food measuring utensils and also nutritional knowledge were evaluated via a questionnaire and some visual materials. Findings Knowledge of portion sizes, amount of food each utensil holds and nutrition was evaluated via a questionnaire and some visual materials. Knowledge of portion size with respect to food groups (p = 0.015), meals (p < 0.001) and food measuring utensils (p = 0.002) and nutritional knowledge scores (p = 0.011) differed based on body mass indexes (BMI). Women had on mean a higher nutritional knowledge score than men (2.0 ± 1.3, 1.9 ± 1.1 points, respectively). The probability of having knowledge about food measuring utensils was 1.4-fold greater for individuals who had been previously educated about nutrition (p = 0.034). Individuals of the faculty of health sciences had higher mean scores for all portion scores (p < 0.05). Originality/value The study findings highlighted that portion knowledge and perception of young adults were affected by gender, BMI, enrolled faculty and nutritional knowledge status. This is the first study, through which the portion knowledge and perception subcomponents (food, meal and measuring utensils) are evaluated, indicating each subcomponent to be affected by distinct factors.
