The use of a food logging app in the naturalistic setting fails to provide accurate measurements of nutrients and poses usability challenges

Large discrepancies in nutrient measurements from MyFitnessPal indicate suboptimal performance with using the app to record intake, particularly given food omissions in records and difficulties encountered with app usability relating to the food database and input of portion sizes. Stand-alone use of MyFitnessPal is therefore cautioned and guidance from dietitians is necessary to support use of nutrition apps in collecting accurate dietary data.