Assessment of the accuracy of nutrient calculations of five popular nutrition tracking applications

Objective To assess the accuracy of nutrient intake calculations from leading nutrition tracking applications (apps).Design Nutrient intake estimates from thirty 24 h dietary recalls collected using Nutrition Data System for Research (NDSR) were compared with intake calculations from these recalls entered by the researcher into five free nutrition tracking apps. Apps were selected from the Apple App Store based on consumer popularity from the list of free 'Health and Fitness' apps classified as a nutrition tracking apps.Subjects Dietary recall data collected from thirty lower-income adults.Results Correlations between nutrient intake calculations from NDSR and the nutrition tracking apps ranged from 0·73 to 0·96 for energy and macronutrients. Correlations for the other nutrients examined (Na, total sugars, fibre, cholesterol, saturated fat) ranged from 0·57 to 0·93. For each app, one or more mean nutrient intake calculations were significantly lower than those from NDSR. These differences included total protein (P=0·03), total fat (P=0·005), Na (P=0·02) and cholesterol (P=0·005) for MyFitnessPal; dietary fibre (P=0·04) for Fitbit; total protein (P=0·0004), total fat (P=0·008), Na (P=0·002), sugars (P=0·007), cholesterol (P=0·0006) and saturated fat (P=0·005) for Lose It!; Na (P=0·03) and dietary fibre (P=0·005) for MyPlate; and total fat (P=0·03) for Lifesum.Conclusions Findings suggest that nutrient calculations from leading nutrition tracking apps tend to be lower than those from NDSR, a dietary analysis software developed for research purposes. Further research is needed to evaluate the validity of the apps when foods consumed are entered by consumers.