To evaluate the validity of food photographs used to support the reporting of food intake with an FFQ designed for adolescents from Rio de Janeiro, Brazil.

A set of ninety-five food photographs was elaborated. The photographs’ evaluation process included the acknowledgement of foods and portions in the pictures. In the identification of foods (ninety-five photographs) and typical portions (twelve photographs), the adolescents were requested to answer a structured questionnaire related to the food photographs. The identification of the portion size of amorphous foods (forty-three photographs) was performed using three different portion sizes of actual preparations. The proportions (and 95 % confidence intervals) of adolescents who correctly identified foods and portion size in each photograph were estimated.

A public school in Niterói, Rio de Janeiro State, Brazil.

Sixty-two adolescents between 11·0 and 18·9 years old, randomly selected.

At least 90 % of adolescents correctly identified the food in ninety-two photographs and the food in the three remaining photographs was recognized by 80–89 % of the adolescents. At least 98 % of the adolescents correctly identified eleven typical or natural portions in the food photographs. For amorphous foods, at least 70 % of teenagers correctly identified the portion size in the photograph of thirty-one foods; for the other photographs, the portion size was correctly recognized by 50–69 % of the adolescents for eight foods and by less than 50 % of adolescents for four foods.

The analysed photographs are appropriate visual aids to the reporting of food consumption by adolescents.