To determine perception v. actual intakes of energy-dense nutrient-poor ‘junk food’ (JF) and sugar-sweetened beverages (SSB) in young adults, using the mobile food record (mFR).

Before-and-after eating images using a 4 d mFR were assessed for standardised 600 kJ (143 kcal) servings of JF and SSB (excluding diet drinks). Participants reported their concern about the health aspects of their diet, perceptions and intentions regarding JF and SSB.

Perth, Western Australia.

Adults (n 246) aged 18–30 years.

The mean (sd) intake of JF+SSB was 3·7 (2·0) servings/d. Women thinking about drinking less SSB consumed more SSB servings/d (1·5 (1·2)) than men (0·7 (0·5); P<0·05) who were thinking about drinking less. Men not thinking about cutting down JF consumed more servings/d (4·6 (2·4)) than women (2·5 (0·7); P<0·01) who were not thinking about cutting down. Those who paid a lot of attention to the health aspects of their diet consumed less JF+SSB than those who took only a bit of notice (P<0·001), were not really thinking much about it (P<0·001) or who didn’t think at all about the health aspects of food (P<0·01).

Perceptions and attitudes regarding JF and SSB were associated with level of consumption. Those not thinking about cutting down their intake of these foods represent an important target group as they consume more than their peers. Further research is needed to identify how amenable young adults are to changing their intake, particularly given the lack of attention paid to the health aspects of their diet.

To evaluate adolescents’ abilities to identify foods and estimate the portion size of foods consumed in order to inform development of the mobile telephone food record (mpFR).

Data were collected from two samples of adolescents (11–18 years). Adolescents in sample 1 participated in one lunch (n 63) and fifty-five of the sixty-three adolescents (87 %) returned for breakfast the next morning. Sample 2 volunteers received all meals and snacks for a 24 h period. At mealtime, sample 1 participants were asked to write down the names of the foods. Sample 2 participants identified foods in an image of their meal 10–14 h postprandial. Adolescents in sample 2 also estimated portion sizes of their breakfast foods and snacks.

Sample 1 identified thirty of the thirty-eight food items correctly, and of the misidentified foods all were identified within the correct major food group. For sample 2, eleven of the thirteen food items were identified correctly 100 % of the time. Half of the breakfast and snack foods had at least one portion size estimate within 10 % of the true amount using a variety of measurement descriptors.

The results provide evidence that adolescents can correctly identify familiar foods and they can look at an image of their meal and identify the foods in the image up to 14·5 h postprandial. The results of the present study not only inform the development of the mpFR but also provide strong evidence of the use of digital images of eating occasions in research and clinical settings.