Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Feb 13, 2020
Date Accepted: Sep 2, 2020
Accuracy of nutrient calculations using the consumer focused online application MyFitnessPal
ABSTRACT
Background:
Digital food registration via online platforms that are coupled to large food databases obviates the need for manual processing of dietary data. Reliability of such platforms depends on the quality of the associated food database.
Objective:
In this study we validated the database of MyFitnessPal (MyFP) versus the Belgian Food Composition Database Nubel.
Methods:
After careful instructions, 50 participants recorded twice (T1 and T2) a 4-day diary using MyFP. Nutrient intake values were calculated either manually using the Food Composition Database Nubel or automatically using the database coupled to MyFP. First, nutrient values from T1 were used as training set to develop an algorithm that defined upper limit values for energy intake, carbohydrates, fat, protein, fibre, sugar, cholesterol and sodium. These limits were applied to the MyFP dataset extracted at T2 to remove extremely high and likely erroneous values. Original and cleaned T2 values were correlated with the Nubel calculated values. Bias was estimated using Bland-Altman plots. Finally, we simulated the impact of using MyFP for nutrient analysis instead of Nubel on the power of a study design that correlates nutrient intake to a chosen outcome variable.
Results:
Cleaning the dataset extracted at T2 resulted in a 2.8% rejection. Cleaned MyFP values demonstrated strong correlations with Nubel for energy intake (r = 0.96), carbohydrates (r = 0.90), fat (r = 0.90), protein (r = 0.90), fibre (r = 0.80) and sugar (r = 0.79), but weak correlations for cholesterol (ρ = 0.51) and sodium (ρ = 0.53); all P ≤ 0.001. No bias was found between both methods, except for a fixed bias for fibre and a proportional bias for cholesterol. A 5-10% power loss should be taken into account when correlating energy intake and macronutrients obtained with MyFP to an outcome variable, compared to Nubel.
Conclusions:
Dietary analysis with MyFP is accurate and efficient for total energy intake, macronutrients, sugar and fibre but not for cholesterol and sodium.
Citation
Per the author's request the PDF is not available.
Copyright
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