Understanding Heterogeneity in Individual Responses to Digital Lifestyle Intervention through Self-monitoring Adherence Trajectories in Overweight or Obese Adults: A Secondary Analysis of 6-month Randomized Controlled Trial (Preprint)

Abstract

Achieving clinically significant weight loss through lifestyle interventions for obesity management is challenging for most individuals. Improving intervention effectiveness involves early identification of intervention non-responders and providing them with timely, tailored interventions. Early and frequent self-monitoring (SM) adherence predicts later weight loss success, making it a potential indicator for identifying non-responders in the initial phase.

This study aimed to identify clinically meaningful participant subgroups based on longitudinal adherence to SM of diet, activity, and weight, over 6 months, as well as psychological predictors of participant subgroups from a Self-Determination Theory (SDT) perspective.

This was a secondary data analysis of a 6-month digital lifestyle interventions for overweight/obese adults. Participants were instructed to perform daily SM on 3 targets: diet, activity, and weight. Data from 50 participants (mean age: 53.0 ± 12.6 years) were analyzed. Group-based multi-trajectory modeling were performed to identify subgroups with distinct trajectories in SM adherence across the 3 SM targets. Differences between subgroups were examined on changes in clinical outcomes (i.e., body weight, hemoglobin A1c (HbA1c)) and SDT constructs (i.e., eating-related autonomous motivation, perceived competence for diet) over 6 months, using linear mixed models.

Two distinct SM trajectory subgroups emerged: the “Lower SM Group” (42%), characterized by “all-round low and rapidly declining SM” and the “Higher SM Group” (58%), characterized by “moderate and declining diet and weight SM with high activity SM”. Since week 2, participants in the Lower SM Group exhibited significantly lower levels of diet (p = .0026), activity (p = .002), and weight SM (p = .022) compared to the higher SM group. For clinical outcomes, the Higher SM group achieved a significant reduction in body weight (-6.06 ± 0.87 kg, p < .0001) and HbA1c (-0.38 ± 0.11%, p = .0188), while the Lower SM group exhibited no improvements. For SDT constructs, both groups maintained high levels of autonomous motivation over 6 months. However, the Lower SM group experienced a significant decline in perceived competence (p = .005) compared to the Higher SM group, which remained a high level of perceived competence throughout the intervention (p = .089)

The presence of the Lower SM Group highlights the value of using longitudinal SM adherence trajectories as an intervention response indicator. Future adaptive trials should identify non-responders within the initial 2 weeks based on their SM adherence and integrate intervention strategies to enhance perceived competence for diet to benefit non-responders.

ClinicalTrials.gov NCT05071287

RR2-10.1016/j.cct.2022.106845