# The same, only different: Smartphone‐based dietary Ecological Momentary Assessment tools vary in complexity, usability and active information processing

## TL;DR

This study shows that more complex smartphone-based dietary tracking tools are seen as harder to use but may encourage more active thinking about food.

## Contribution

The study experimentally demonstrates that EMA tool complexity affects perceived active information processing.

## Key findings

- Protocols with more tracking features were perceived as more complex.
- More complex protocols were associated with higher perceived active information processing.
- No differences were found in perceived impact on eating-related cognitions or behavior.

## Abstract

Ecological Momentary Assessment (EMA) is popular for assessing dietary intake in real life and real time. Available tools differ substantially in the type and number of implemented features, including features to assess what and how much was consumed. These features require qualitatively different input that might have a differential impact on the participants' cognitions and behaviours while taking part in the study. This study aimed to test whether more complex dietary assessment tools, indicated by the type and number of assessment features, induce more active information processing (AIP).

Preregistered online between‐subjects experimental study.

A total of 373 participants (65.4% female; mean age 30.4 years) were randomly allocated to view one of eight EMA protocol mock‐ups, each describing a food tracking process verbally and using screenshots. Afterwards, they rated the protocol in terms of its complexity (manipulation check), AIP and its potential impact on eating‐related cognitions, intentions and eating behaviour change.

The eight EMA protocols differed in perceived complexity, that is protocols with more tracking features were perceived as more complex compared to those with fewer tracking features. EMA protocols that were perceived to be more complex were also perceived to induce more AIP. However, there were no differences in perceived impact on eating‐related cognitions, intentions and behaviour.

Differences in complexity and usability may influence compliance and study results. Researchers thus need to carefully select the appropriate EMA protocol for their study to balance the need for collected information with the need for high compliance.