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

A Theory-based Digital Intervention to Promote Weight Loss and Weight Loss Maintenance (Choosing Health): A Randomised Controlled Trial With Within Person Assessment

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Overweight and Obesity
• Intervention / Treatment: Behavioral: Choosing Health Intervention; Behavioral: Choosing Health Control

Detailed Description

Behavioural science offers theory-driven and evidence-based behaviour change techniques that can support people in losing weight and maintaining it long term. These techniques have not yet been assessed in within-person studies that not only examine aggregated between-group effects (e.g., intervention versus control comparisons) but also determine personal trajectories of weight loss and maintenance and tailor accordingly to the strongest predictors of outcomes. The aim of the proposed study is to develop and test a digital intervention that uses Ecological Momentary Assessment (EMA) and tailors the evidence-based behaviour change techniques that are based on theory to the strongest predictors of outcomes (based on EMA responses collected over time).

This study will determine the effectiveness and cost-effectiveness of the proposed intervention through the Randomised Controlled Trial (EMA tailored intervention versus control), with within person component embedded in the trial. Study hypothesis is that participants in the EMA tailored intervention group will lose significantly more weight than participants in the control group from baseline to 6 months (post program comparison - primary outcome) and at 12 months (maintenance effects assessment - secondary outcome).

This is a two-group intervention trial adopting a randomised controlled design. It is a hybrid trial assessing intervention effectiveness, cost-effectiveness and implementation. This study has within person component embedded in the design and intervention group will answer EMA questions during the initial 3 months of the study and will receive tailored intervention at month 3 combined with additional EMA. There are two phases of the 6-month intervention (I) observational EMA phase and (II) active intervention phase.

The proposed intervention is delivered online through emails and text messages and based on the EMA responses in phase I, it is tailored in phase II. The intervention will have a non-automatic component, meaning trained facilitators will answer participants' queries and provide additional resources if and when needed to improve the engagement with the intervention. The study meets CONSORT criteria for RCTs and study ethical approval was obtained from SWPS University of Social Sciences and Humanities, Wroclaw, Poland (approval number 03/P/12/2019).

• Study Type: Interventional
• Enrollment (Actual): 285
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Slaskie
    • Wroclaw, Slaskie, Poland, 03-815
      • SWPS University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Adults with overweight and obesity (18+);
• Individuals with a BMI 25 and higher at the baseline assessment.

Exclusion Criteria:

• Individuals who self-report a physical condition or impairment preventing them from being physically active or losing excess body weight;
• Individuals who have had a bariatric surgery or are planning to have one within the next 12 months;
• Individuals who are currently participating in another weight loss program (e.g., regular meetings with personal trainer);
• Individuals who report any contradictions to exercise as indicated by the PAR-Q or pregnant women who consulted their doctor to obtain approval to take part in the study and did not get the approval;
• Individuals who do not have a mobile phone with access to the internet;
• Individuals who are currently participating in another weight loss program (e.g., regular meetings with personal trainer);
• Pregnant women;
• Individuals who are planning to move outside of the study region and are not willing to travel for study measurement sessions;
• Individuals who are on medication that causes weight gain;
• Individuals with a pacemaker (the scale used in the study is not appropriate for use in these individuals).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention arm; The intervention group participants will be assessed with EMA and they will provide daily data regarding their predictors of weight loss outcomes and their adherence to the personal weight loss plan (phase I, month 0-3). Then participants will receive tailored information regarding the most predictive factors relevant to their weight loss trajectories (phase II, month 3-6). The information will be tailored and delivered through emails and text messages.	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.
Other: Control arm; Control group participants will receive basic educational weight loss information in a form of educational factual emails and text messages.	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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight	Mean difference in weight loss between groups at 6 months, in kilograms	Change from baseline to 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight	Objective measures of weight in kilograms	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Height	Objective measures of height in centimetres	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
BMI	Weight and height will be combined to report BMI in kg/m^2	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Body fat %	Objective measures of body fat %	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Systolic and diastolic blood pressure	Objective measures of systolic and diastolic blood pressure measured in units of millimeters of mercury (mmHg)	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Diet	Measured with the Dietary Instrument for Nutrition Education (fatty foods, fruit and vegetable, and sugary food consumption). High scores are indicative of high consumption. Higher scores for fruit and vegetable mean a better outcome (0-3 scale; 1 item) and higher scores for fatty foods (0-24; 8 items on 0-3 scale) and sugary food (0-9; 3 items on 0-3 scale) mean a worse outcome. The minimum values are 0 and the maximum values are specified above in brackets.	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Alcohol	Measured with the Audit C; scale 0-12, high scores are indicative of high consumption.	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Physical activity (self-reported) and sitting time	Measured with the International Physical Activity Questionnaire short version, the minimum value is 0 (no activity), higher scores mean a better outcome. All activity will be converted to minutes before calculating MET minutes (total score). In each category a maximum of 21 hours of activity are permitted a week (3 hours X 7 days). To calculate MET minutes a week the MET value given (walking = 3.3, moderate activity = 4, vigorous activity = 8) will be multiplied by the minutes the activity was carried out and again by the number of days that that activity was undertaken. To get total MET minutes of physical activity a week the MET minutes achieved in each category (walking, moderate activity and vigorous activity) will be added.	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Sleep duration and quality	Measured with the Pittsburgh Sleep Quality Index. In scoring the Pittsburgh Sleep Quality Index, seven component scores are derived, each scored 0 (no difficulty) to 3 (severe difficulty). The component scores are summed to produce a global score (range 0 to 21). Higher scores indicate worse sleep quality.	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Health related quality of life	Measured with the EQ-5D-5 L (this is the unabbreviated scale title), the scale has five domains each scored on 1-5 scale; min 5 maximum 25 for all domains combined) higher scores mean a worse outcome and visual analogue scale is the second part of the questionnaire, asking to mark health status on the day of the interview on a 20 cm vertical scale with end points of 0 and 100. There are notes at the both ends of the scale that the bottom rate (0) corresponds to " the worst health you can imagine", and the highest rate (100) corresponds to "the best health you can imagine".	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Number of adverse effects	report of any adverse effects that may occur during the intervention	Through study completion, an average of 1 year
Self-reported measures of intentions	Theory-derived psychological construct measured with 2 items addressing intentions (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a better outcome (higher intentions).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of motivation	Theory-derived psychological construct measured with 2 items addressing motivation (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a better outcome (higher motivation).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of self-efficacy	Theory-derived psychological construct measured with 2 items addressing self-efficacy (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a better outcome (higher self-efficacy).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of attitudes	Theory-derived psychological construct measured with 2 items addressing attitudes (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a better outcome (higher attitudes).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of action planning	Theory-derived psychological construct measured with 8 items addressing action planning (1-5 scale), the minimum and maximum values for the scale are 8-40, and higher scores mean a better outcome (better action planning).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of coping planning	Theory-derived psychological construct measured with 6 items addressing action planning (1-5 scale), the minimum and maximum values for the scale are 6-30, and higher scores mean a better outcome (better coping planning).	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of goal facilitation	Theory-derived psychological construct measured with 2 items addressing goal facilitation (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a better outcome (better goal facilitation)	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of goal conflict	Theory-derived psychological construct measured with 2 items addressing goal conflict (1-5 scale), the minimum and maximum values for the scale are 2-10, and higher scores mean a worse outcome (higher goal conflict)	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of habit strength for physical activity	Theory-derived psychological construct measured with h self-report behavioural automaticity index for physical activity, 4 items (1-5 scale); the minimum and maximum values for the scale are 4-20, and higher scores mean a better outcome (habit strength)	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)
Self-reported measures of habit strength for healthy eating	Theory-derived psychological construct measured with self-report behavioural automaticity index for healthy eating, 4 items (1-5 scale); the minimum and maximum values for the scale are 4-20, and higher scores mean a better outcome (habit strength)	baseline (Time 0), 3 months (Time 1), 6 months (Time 2) and 12 months (Time 3)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Demographic variables	Age, sex, marital status, ethnicity, education, height (to calculate BMI), and household income	baseline (Time 0)

Collaborators and Investigators

• Sponsor: University of Social Sciences and Humanities, Warsaw
• Investigators: Principal Investigator: Felix Naughton, PhD, University of East Anglia; Principal Investigator: Aleksandra Luszczynska, Prof, SWPS University of Social Sciences and Humanities; Principal Investigator: Dominika Kwasnicka, PhD, SWPS University of Social Sciences and Humanities; Principal Investigator: Martin Hagger, Prof, University of California; Principal Investigator: Eleanor Quested, PhD, Curtin University

Publications and helpful links

General Publications

• Kwasnicka D, Luszczynska A, Hagger MS, Quested E, Pagoto SL, Verboon P, Robinson S, Januszewicz A, Idziak P, Palacz I, Naughton F. Theory-based digital intervention to promote weight loss and weight loss maintenance (Choosing Health): protocol for a randomised controlled trial. BMJ Open. 2020 Nov 23;10(11):e040183. doi: 10.1136/bmjopen-2020-040183.

Helpful Links

• Study website

Study record dates

Study Major Dates

• Study Start (Actual): July 30, 2020
• Primary Completion (Anticipated): April 30, 2022
• Study Completion (Anticipated): December 31, 2022

Study Registration Dates

• First Submitted: February 4, 2020
• First Submitted That Met QC Criteria: February 27, 2020
• First Posted (Actual): March 2, 2020

Study Record Updates

• Last Update Posted (Actual): September 29, 2021
• Last Update Submitted That Met QC Criteria: September 28, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Keywords: Weight loss; Physical activity; Diet; Behaviour change; Digital health; Behaviour maintenance; Within-person design
• Additional Relevant MeSH Terms: Body Weight; Body Weight Changes; Weight Loss; Overweight
• Other Study ID Numbers: POIR.04.04.00-00-5CF3/18-00

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: We will share anonymised data using Open Science Framework.
• IPD Sharing Time Frame: The data will be available on the OSF after the study is completed.
• IPD Sharing Access Criteria: Anonymised data will be publicly available to access through the OSF.
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP); Informed Consent Form (ICF); Clinical Study Report (CSR); Analytic Code

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No