Assessing the validity and acceptability of DietPhone as a dietary measurement tool in adolescent girls

Introduction Dietary assessment is essential for investigating the relationship between diet and disease. Previously it has been assumed that dietary measures used in adults were appropriate in younger age groups. However research has highlighted that measuring the diets of adolescents in particular, poses unique challenges (Livingstone et al, 2004). It has been suggested the development of new and innovative techniques for obtaining dietary intakes of adolescents could improve the accuracy of reporting in this age group. This study aims to investigate whether DietPhone is a valid dietary assessment tool and whether it is acceptable to use with adolescents. Methods Eleven third year girls were required to keep a five day dietary record using both diet diaries and DietPhone over separate time periods. Comparisons of the mean daily intakes of energy, protein, carbohydrate, total fat and calcium were made between the two methods. Using the Bland & Altman technique, the level of agreement between the two methods was determined. Additionally focus groups were carried out to establish whether this group found DietPhone to be acceptable to use. Results At the group level, analysis revealed good agreement between the two methods for carbohydrate, with a mean difference of 15.9g being observed. However there appears to be a lack of agreement for intakes of energy, protein, total fat and calcium, with mean differences of 169kcal, 9.3g, 8.3g and 72mg respectively. Furthermore wide limits of agreement were observed for all the nutritional parameters measured, suggesting a lack of agreement at the individual level. Nevertheless DietPhone was established as the preferred method of choice during the focus groups. In addition the group identified several modifications that could ultimately improve DietPhone. Conclusion Due to the lack of agreement observed between the two methods, it is not appropriate to recommend replacing diet diaries with DietPhone as a dietary assessment tool at this time. However it appears that participants enjoyed using DietPhone and it was favoured over using diet diaries, suggesting this technology is acceptable to use with this population. Therefore in the future, DietPhone has the potential to improve the accuracy of dietary assessment in adolescents.