Validity of a digital photo-based dietary assessment tool: Development and initial evaluation

Background and aim: To evaluate the validity and user satisfaction of a digital photo-based dietary assessment tool as an alternative to the hand-written paper record method that assists researchers during the pandemic. This study compared nutrient intake and users' satisfaction with methods between a digital photo-based dietary assessment tool, known as the Nutrinote Gama app, and food weighing as the gold standard. Methods: Fifty college students majoring in food and nutrition (90% were women; median age, 21 years) took pictures of their foods and beverages before and after consumption and then uploaded them to the Nutrinote Gama application. Trained nutritionists evaluated plate wastes, and nutritional content was revealed on the Nutrinote Gama application. Parallel to the photo-based method, they kept a weight dietary record and sent it to the researcher. A questionnaire was used to assess participants' satisfaction. Results: No statistical differences (p = 0.89) were observed in the measurement of energy intake between Nutrinote Gama (mean ± standard deviation [SD] = 582.8 ± 131) and food weighing (mean ± SD = 566.1 ± 133). No statistical differences (p = 0.59) were also observed in the measurement of protein, fat (p = 0.434), and carbohydrate (p = 230). The energy, protein, fat, and carbohydrate intakes estimated from the two methods were significantly correlated (r = 0.86, 0.870, 0.811, 0.738, respectively). Over 70% of participants were satisfied with the photo-based record. Conclusion: The results indicate that this digital photo-based dietary assessment tool is valid and user-friendly to estimate nutrient intake.