Measuring dietary intake among participants with a urea cycle disorder using standard diet records or a novel food photography app

Abstract

Nutrition management of urea cycle disorders (UCDs) focuses on limiting dietary protein and providing adequate energy to ensure appropriate growth and prevent catabolism. Dietary protein intakes are recommended to patients; however, assessment of actual protein intake is challenging as standard assessment methods are recognized to be inaccurate, time-consuming, and cumbersome. A new dietary collection method utilizes a smartphone camera; participants take photos of meals and snacks for remote analysis by a registered dietitian. This food photography method using the mFood app was compared to traditional 3-day diet records in individuals with UCDs and reported energy intake for both were validated against an objective gold-standard measurement of total energy expenditure (TEE) by doubly labeled water. In weight-stable adults, energy intake is approximately equal to TEE. Eight individuals ≥16 years old participated in a randomized crossover design study. In this cohort, protein intake was 13 % and 15 % of energy for 3-day diet records and mFood, respectively. There was no statistical difference in gram intake of the macronutrients between the two methods. Compared to TEE, participants reported 16 % lower total energy intake by 3-day diet records and 22 % lower energy intake by mFood, demonstrating limited benefit to using mFood. We highlight the importance of utilizing consistent nutrient analysis methods to compare dietary assessments within a population. mFood, although not superior to traditional dietary collection methods, was preferred by the majority of participants and offers a novel method for collecting nutrition information in individuals with UCD who frequently find this task cumbersome.

Keywords: Dietary intake; Doubly labeled water; Food photography; Urea cycle disorder.