Evaluation of a Personalised Digital Intervention (EviBody) for Healthy and Sustained Lifestyle Behaviors and Well-being Among Adults: a Real-world Quasi-experimental Study

Effectiveness and Theory-based Evaluation of a Personalised Digital Intervention (EviBody) for Healthy and Sustained Lifestyle Behaviours and Well-being Among Adults

The goal of this quasi-experimental observational study is to evaluate the impact of a personally tailored digital intervention aimed to support a healthy lifestyle on well-being, lifestyle behaviors, and mental health among the adult population.

The main questions it aims to answer are:

I) Is a digital intervention developed to offer personalised digital support for healthy habits effective in improving well-being compared to a control group from the general population after 6 months? II) Is the effectiveness dose-dependent (better effect with higher membership level)? III) Does the digital intervention assist in maintaining healthy eating and physical activity habits, mental health, and well-being across 24 months? IV) Are sociodemographic factors associated with achieving the self-identified goals and improvements in eating and physical activity habits, mental health, and well-being? VI) Do engagement, motivation, self-efficacy, and perceived barriers mediate the associations between sociodemographic characteristics and changes in self-identified goals, eating and physical activity habits, mental health, and well-being over a 24-month period? V) How is the pattern of user engagement across 24 months?

Participants are users of the mobile phone application EviBody. The group will be compared with individuals from the general population to evaluate if the digital intervention is effective in improving well-being, eating and physical activity habits, and mental health.

Study Overview

• Status: Recruiting
• Conditions: Well-being
• Intervention / Treatment: Behavioral: EviBody- Basic; Behavioral: EviBody- Standard; Behavioral: EviBody- Premium

Detailed Description

EviBody is a personally tailored digital intervention promoting healthy habits that is co-developed, based on behavioural research evidence, and supported by artificial intelligence.

The primary study is a quasi-experimental study with a non-randomised control group. A four-armed design will allow for comparison between three levels of intervention (basic, standard and premium) and a control group. The digital intervention (the app EviBody) will be marketed and managed by its owner LongLife Active AB (Limited Company), Sweden. Allocation to intervention arm is by preference (chosen membership level of the app) and takes place at enrolment. Being a research participant includes answering seven questionnaires during two years and allowing researchers to extract data from app analytics. Ethical approval was obtained from the Swedish Ethical Review Authority, Dnr 2023-06246-01 on January 30 2024.

• Study Type: Observational
• Enrollment (Estimated): 1500

Contacts and Locations

• Study Contact: Name: Jenny Rossen, PhD; Phone Number: +4684062985; Email: jenny.rossen@shh.se
• Study Contact Backup: Name: Unn-Britt Johansson, Professor; Phone Number: +464062902; Email: Unn-Britt.Johansson@shh.se

Study Locations

• Sweden
  • Stockholm, Sweden
    • Recruiting
    • Sophiahemmet University
    • Contact: Jenny Rossen, Associate professor; Phone Number: +4684062985; Email: jenny.rossen@shh.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Intervention:

Adults signing up for a digital intervention that is supporting a healthy lifestyle.

Control:

Adults of the general population.

Description

Inclusion Criteria (intervention arms):

• adults ≥18 years
• signing up for the app EviBody using electronic identification
• consent to the research study

Inclusion Criteria (controls):

• adults ≥18 years
• consent to the research study

Exclusion Criteria (intervention arms):

• individuals who are discharged from the app due to refracting the terms of the service,
• is currently using a digital product that is explicitly designed to support behaviour change,
• subjects scoring >70 on well-being will be excluded from the primary analyses,
• subjects who appear as friends, colleagues, or family with anyone in the research or owner group will be excluded.

Exclusion Criteria (controls):

• is currently using a digital product that is explicitly designed to support behaviour change,
• is found to be a user of EviBody,
• subjects scoring >70 on well-being will be excluded from the primary analyses,
• subjects who appear as friends, colleagues, or family with anyone in the research or owner group will be excluded.

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Control group; No exposure
Intervention group- Basic; Subjects with behavioral support from the app EviBody	Behavioral: EviBody- Basic; The app EviBody with three core subjects: 1) a Healthy eating, 2) Physical activity, and 3) Mental balance. The intervention includes tracking and self-monitoring of behaviors, goal setting, action planning, feedback and digital rewards, an AI chat, a database with food recipes, a database with exercises, inspiration, and skills training webinars.
Intervention group- Standard; Subjects with behavioral support from the app EviBody + social support	Behavioral: EviBody- Standard; The digital service EviBody with three core subjects: 1) a Healthy diet, 2) Physical activity, and 3) Mental balance. The service includes tracking and self-monitoring of behaviors, goal setting, action planning, feedback and digital rewards, an AI chat, a database with food recipes, a database with exercises, inspiration, and skills training webinars. Users with the membership Standard are also offered a community with social support.
Intervention group- Premium; Subjects with behavioral support from the app EviBody + social support + individual coaching	Behavioral: EviBody- Premium; The digital service EviBody with three core subjects: 1) a Healthy diet, 2) Physical activity, and 3) Mental balance. The service includes tracking and self-monitoring of behaviors, goal setting, action planning, feedback and digital rewards, an AI chat, a database with food recipes, a database with exercises, inspiration, and skills training webinars. Users with the membership Premium are also offered a community with social support plus private on-line health consultations. The number of private health consultations is 3 for a 3 months subscription, 4 for a 6 months subscription, and 6 for a 12 months subscription.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Well-being	Well-being will be assessed by the WHO-5 Well-Being Index. The WHO-5 comprises the following five items: being cheerful and in good spirits; being calm and relaxed; feeling active and vigorous; feeling fresh and rested when waking up in the morning; and having an interest in day-to-day activities. Six response alternatives are scored from 5 (All of the time) to 0 (At no time). The total raw score which ranges from 0 to 25 is multiplied by 4 to calculate the final score. The final score range goes from 0 = worst imaginable well-being to 100 = the best imaginable well-being.	6 months
Well-being	Well-being will be assessed by the WHO-5 Well-Being Index. The WHO-5 comprises the following five items: being cheerful and in good spirits; being calm and relaxed; feeling active and vigorous; feeling fresh and rested when waking up in the morning; and having an interest in day-to-day activities. Six response alternatives are scored from 5 (All of the time) to 0 (At no time). The total raw score which ranges from 0 to 25 is multiplied by 4 to calculate the final score. The final score range goes from 0 = worst imaginable well-being to 100 = the best imaginable well-being.	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stress	Stress will be assessed by the Karolinska Exhaustion Disorder Scale (KEDS), a self-rating scale for stress-induced exhaustion disorder. 9 items are scored 1-6, a higher total score indicates more exhaustion.	6 months
Burnout	Burnout will be assessed by the Oldenburg Burnout Inventory (OLBI). 16 items are scored 1-4, a higher total score indicates more burnout.	6 months
Sleep	Sleep will be assessed by the self-reported number of hours of sleep per night and by Insomnia Severity Index (ISI). In ISI 7 items are scored 1-4 and a higher total score indicates more sleeping problems.	6 months
Stress	Stress will be assessed by the Karolinska Exhaustion Disorder Scale (KEDS), a self-rating scale for stress-induced exhaustion disorder. 9 items are scored 1-6, a higher total score indicates more exhaustion.	24 months
Burnout	Burnout will be assessed by the Oldenburg Burnout Inventory (OLBI). 16 items are scored 1-4, a higher total score indicates more burnout.	24 months
Sleep	Sleep will be assessed by the self-reported number of hours of sleep per night and by Insomnia Severity Index (ISI). In ISI 7 items are scored 1-4 and a higher total score indicates more sleeping problems.	24 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Goal achievement	Reaching the self-identified goal will be evaluated by collecting information on number of days/week the self-identified goal was met during the past month. Confidence for reaching the goal will also be asked for on a scale 1 low confidence to 6 high confidence.	6 months
Dietary habits	Dietary behaviours will be assessed by questions from the Social Board of Health and Welfare in Sweden, with the addition of some study specific questions on plant based diet.	6 months
Physical activity	Physical activity will be collected by questions from the Social Board of Health and Welfare with additional questions on active transport and physical activity at work. In a randomized sample of individuals having increased physical activity as a goal (n=300) physical activity will also be measured objectively by the use of the three-axial accelerometer-based device.	6 months
Sedentary behavior	Sedentary behavior will be collected by questions from the Social Board of Health and Welfare with additional questions on active transport and physical activity at work. In a randomized sample of individuals having increased physical activity as a goal (n=300) physical activity will also be measured objectively by the use of the three-axial accelerometer-based device.	6 months
Daily number of steps	Daily number of steps will be obtained from app analytics.	6 months
Goal achievement	Reaching the self-identified goal will be evaluated by collecting information on number of days/week the self-identified goal was met during the past month. Confidence for reaching the goal will also be asked for on a scale 1 low confidence to 6 high confidence.	24 months
Dietary habits	Dietary behaviours will be assessed by questions from the Social Board of Health and Welfare in Sweden, with the addition of some study specific questions on plant based diet.	24 months
Physical activity	Physical activity will be collected by questions from the Social Board of Health and Welfare with additional questions on active transport and physical activity at work. In a randomized sample of individuals having increased physical activity as a goal (n=300) physical activity will also be measured objectively by the use of the three-axial accelerometer-based device.	24 months
Sedentary behavior	Sedentary behavior will be collected by questions from the Social Board of Health and Welfare with additional questions on active transport and physical activity at work. In a randomized sample of individuals having increased physical activity as a goal (n=300) physical activity will also be measured objectively by the use of the three-axial accelerometer-based device.	24 months
Daily number of steps	Daily number of steps will be obtained from app analytics.	24 months

Collaborators and Investigators

• Sponsor: Sophiahemmet University
• Collaborators: Karolinska Institutet; Linnaeus University; The Swedish School of Sport and Health Sciences; Stockholm University
• Investigators: Principal Investigator: Jenny Rossen, PhD, Sophiahemmet University

Publications and helpful links

General Publications

• Rossen J, Anderbro T, Andermo S, Bergman P, Hagstromer M, Jacobsson M, Johansson UB, Kallings L, Lonn A, Regan C, von Rosen P. Effectiveness and theory-based evaluation of a personalised digital intervention (EviBody(R)) for healthy and sustained lifestyle behaviours and well-being among adults: Study protocol for a real-world quasi-experimental study. PLoS One. 2025 Oct 7;20(10):e0333201. doi: 10.1371/journal.pone.0333201. eCollection 2025.

Helpful Links

• Research project website

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: July 8, 2023
• First Submitted That Met QC Criteria: August 1, 2023
• First Posted (Actual): August 2, 2023

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: self-management; behavior; primary prevention; secondary prevention; health promotion
• Additional Relevant MeSH Terms: Behavior
• Other Study ID Numbers: CIV-23-07-043416

Drug and device information, study documents

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