A Theory-based Digital Intervention to Promote Weight Loss and Weight Loss Maintenance

Summary

Obesity can severely reduce quality and longevity of life and there is an urgent need to help people lose weight and maintain weight loss long term. Digital behaviour change interventions targeting diet and physical activity have the potential for public health gain; however, these interventions are often not adequately tailored to the participants. The aim of this study is to develop and test a digital intervention to help people make sustainable changes to diet and physical activity, and consequently their weight. This study is a hybrid trial that will evaluate the effectiveness, cost-effectiveness and implementation of the Choosing Health program among overweight/obese adults.

This study is a two-group randomised controlled trial (RCT) with within person assessment. Participants (N=285) will be randomly assigned to either the Choosing Health digital intervention or a control group. For intervention participants, Ecological Momentary Assessment (EMA) will be used to identify behavioural determinants for each individual in order to tailor evidence-based behaviour change techniques and intervention content. Control group will receive non-tailored factual weight loss advice. Primary outcome is mean difference in weight loss between groups at 6 months, in kilograms. Key outcomes will be measured at baseline, 3-, 6- and 12 months. Data will be analysed using multilevel modelling and time series analysis.

This is the first weight loss intervention applying individualised digital tailoring based on continuous assessment of individual's psychological determinants of behaviour measured over time. The Choosing Health will offer insight into factors associated with success in making sustained changes to weight, and secondary outcomes, such as diet and physical activity.

Conditions

• Overweight and Obesity

Interventions

BEHAVIORAL

Choosing Health Intervention

The intervention consists of information materials provided at baseline in a form of eBook or a physical book depending on participants preferences. The book includes the rationale for the intervention, basic information on healthy eating and behaviour change and tables allowing self-monitoring of weight, physical activity and eating (i.e., brief food diary). The book is non-tailored and it has weekly tasks for the participants to complete during 26 weeks (initial 6 months) to support their weight loss. The intervention group will also receive a series of daily text messages and weekly email messages supporting their weight loss and promoting weight loss maintenance. In phase I (month 0-3), the messages and emails will be generic and factual; in the phase II of the intervention, participants will receive text messages and emails tailored to the strongest predictors of outcomes identified in phase I.

BEHAVIORAL

Choosing Health Control

The control consists of information materials provided at baseline in a form of eBook or a physical book depending on participants preferences. The book includes the rationale for the intervention and basic information on healthy eating and physical activity. The control group will also receive monthly email messages with generic and factual information.

Sponsors & Collaborators

• University of Social Sciences and Humanities, Warsaw

  lead OTHER

Principal Investigators

• Felix Naughton, PhD · University of East Anglia

• Aleksandra Luszczynska, Prof · SWPS University of Social Sciences and Humanities

• Dominika Kwasnicka, PhD · SWPS University of Social Sciences and Humanities

• Martin Hagger, Prof · University of California

• Eleanor Quested, PhD · Curtin University

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-07-30

Primary Completion

2022-04-30

Completion

2022-12-31

Countries

• Poland