Effectiveness of a Smartphone Application for Dietary Sodium Intake Measurement

Figure 1. Flow diagram of the study.

Figure 2. Features of the Noom Health application. (A) Participants were instructed to log their meals throughout the day using the smartphone application by selecting the ‘Log your meals’ icon, where participants first selected (B) which meal (breakfast, morning snack, lunch, afternoon snack, dinner, or evening snack) they were logging. (C) Participants then logged the type of meal by typing their meal in the grey search box (D) and selected the amount and units of food they had consumed by swiping their fingers across the blue tape measure and the units tab above, respectively. (E) Participants could also view key nutritional facts (serving calories, total fat, saturated fat, trans fat, cholesterol, sodium, potassium, total carbohydrates, dietary fiber, sugars, and protein) related to the selected food (F). They were also able to monitor their daily calorie and sodium intake throughout the day.

Figure 3. Correlation between dietary sodium intake measured by the smartphone application and that calculated using 24-h urine sodium at (A) baseline and (B) 6 months after enrollment.

Figure 4. Bland-Altman plots showing mean difference and limits of agreement between dietary sodium intake measured by the smartphone application and that calculated using 24-h urine sodium at (A) baseline and (B) 6 months after enrollment. (A) Mean difference = −836.8, limits of agreement = −70.3, 1797.0, (B) Mean difference = −24.1, limits of agreement = −76.3, 4646.4.