Development and Validation of a Brief Instrument to Measure Knowledge About the Energy Content of Meals.

OBJECTIVE: To develop and validate a brief scale to assess knowledge about the energy content of meals for adults in Switzerland. METHODS: Based on a random sample, the scale was developed using a Rasch model approach. To assess validity and reliability, the model was replicated and scores were compared with another nutrition knowledge measure and with dietitian trainees' scores. A test-retest was performed. RESULTS: Survey studies included 477, 505, and 136 participants from the general population and 59 dietician trainees. The Rasch scale consisted of 11 multiple-choice items ranging from easy to difficult and correlated with general nutrition knowledge (r = .47; P < .001; r2 = .22). Dietitian trainees achieved higher scores (P < .001; d = 2.17) than did people from the general population; test-retest reliability results were r = .73, P < .001, and r2 = .53. CONCLUSIONS AND IMPLICATIONS: Results showed that the scale is efficient, valid, and reliable for use in the general population in Switzerland.

Consumers' practical understanding of healthy food choices: a fake food experiment.

Little is known about laypeople's practical understanding of a healthy diet, although this is important to successfully promote healthy eating. The present study is the first to experimentally examine how consumers define healthy and balanced food choices for an entire day compared with normal choices and compared with dietary guidelines. We used an extensive fake food buffet (FFB) with 179 foods commonly consumed in the Swiss diet. The FFB is a validated method to investigate food choice behaviour in a well-controlled laboratory setting. People from the general population in Switzerland (n 187; 51·9 % females), aged between 18 and 65 years, were randomly assigned to one of two conditions. In the control group, the participants were instructed to serve themselves foods they would eat on a normal day, whereas in the 'healthy' group they were instructed to choose foods representing a healthy diet. Participants chose significantly more healthy foods, with 4·5 g more dietary fibre, 2 % more protein and 2 % less SFA in the 'healthy' group compared with the control group. However, in both experimental conditions, participants served themselves foods containing twice as much sugar and salt than recommended by dietary guidelines. The results suggest that laypeople lack knowledge about the recommended portion sizes and the amounts of critical nutrients in processed food, which has important implications for communicating dietary guidelines. Furthermore, the energy of the food served was substantially correlated with the energy needs of the participants, demonstrating the potential of the fake food buffet method.