Taking people in GreeceNo phase

Tests a phone app and smartwatch for preventing weight gain in adults

Tests a phone app and smartwatch that track daily habits in adults.

Key facts

Who runs it: Harokopio University
Where: Athens, GreeceSee the siteAlso in 6 other countries, 6 sites
Trial code: NCT07120802
Registry title: Better4All Personalized Intervention Pilot Study
Status: Recruiting
People taking part: 490 people, planned
Started: 1 Jun 2025
Planned end: 30 Sept 2025
Type of study: Interventional, 2 groups
Treatments tested: BETTER4U Mobile App and Wearable Use (End-User Group)
BETTER4U Intervention Platform Testing (Implementer Group)
Record updated: 13 August 2025

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults aged 18-65 from the general population, with normal weight or overweight/obesity, who can use a smartwatch and an Android app for three weeks.

Age: 18 to 65 years
Sex: All sexes can join
Disease stage: Body Mass Index (BMI) of 25 kg/m² or higher (overweight or obesity), or BMI of 18.5-24.9 kg/m² (normal weight)

Main reasons for not taking part

Pregnant or breastfeeding women
A physical or mental condition that prevents use of the wearable device or the app
Eating with chopsticks daily or regularly
No compatible Android smartphone, or unable to use the wearable device
Not a resident of one of the seven participating countries

The registry criteria, word for word

Show all 12 criteriaShow less

Who can take part

Age: Participants aged 18-65 years to represent the adult general population
Body Mass Index (BMI):; Overweight or obesity group: BMI ≥ 25 kg/m²; Normal weight group: BMI 18.5-24.9 kg/m²
Technology Use:; Willingness and ability to use wearable devices and an Android mobile application for the duration of the study; Owning a smartphone device with the Android operating system
Eating utensil technique: dominant hand gestures that correspond to handling of food via a fork or a spoon
Language Proficiency: Ability to read and understand the language in which the mobile app and study materials are provided
Consent: Willing to provide informed consent to participate in the study
Residency: Must be a resident of one of the seven participating countries
Availability: Able to participate for the full three-week duration of the study and comply with the study protocol

Who cannot take part

Health Conditions: Pregnant or breastfeeding women, as they might have different lifestyle behaviours or health needs
Physical Limitations: Any physical or mental condition that would prevent the participant from using the wearable device or mobile application as intended
Eating utensil technique: eating food with chopsticks on a daily or regular basis
Technical Incompatibility: Individuals who do not own a compatible smartphone or are unable to use the provided wearable devices for technical reasons

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

Are you between 18 and 65 years old?

Where in Greece

Also in 6 other countries, 6 sites

Harokopio UniversityAthens, GreeceContact: Yannis Manios, ProfessorTaking people

About the trial

What the trial wants to find out

The BETTER4U project (Preventing obesity through Biologically and bEhaviorally Tailored inTERventions for you) is funded by the European Union (EU) and involves an international consortium consisting of 28 partners across Europe, Israel, and Australia. The project started in November 2023 and will run until October 2027. The main aim of BETTER4U is to improve weight management through a tailor-made intervention, the "BETTER4ALL personalized intervention", using modern monitoring tools and artificial intelligence (AI), including machine learning (ML) practices.

Read full original descriptionShow less

In the context of the BETTER4U project, the present Pilot Study aims to a) evaluate the usability, feasibility and acceptability of the BETTER4U mobile application ("BETTER4U App") and Intervention Platform that will be used to monitor and collect data from participants in the BETTER4ALL personalized intervention (randomized controlled trial; RCT) and b) collect data to evaluate and improve the BETTER4U causal AI models for the prevention of weight gain, before deploying them at large scale, as well as test and identify the optimal ways of delivering the AI-based interventions to the participants. The study will be conducted in seven sites in Cyprus, France, Greece, Poland, Portugal, Spain, and Sweden.

The BETTER4All Pilot Study will be a longitudinal, correlational, observational study, including a total of n=490 participants, equally distributed among the seven sites (i.e. n=70 per site). Specifically, n=60 (± 3-5) "general population" participants (henceforth: "end-users" of the wearables and the BETTER4U App) and n=10 (± 3-5) healthcare or other types of providers (henceforth: potential "implementers" of the BETTER4U intervention) will constitute each site's sample.

The study will involve the following two components: a) the administration of the wearables (smartwatches) to the "end-users" and their registration to and training on the BETTER4U App, to be used for a total duration of three weeks (21 days). During this period, their lifestyle behaviours (i.e. "BETTER4U Core Behavioural Indicators - BCBIs", such as eating occasions, physical activity, sedentary time, sleep etc.) and "living environment indicators - LEIs"; (e.g. access to parks in your area, distance from your home to your work place etc.) will be recorded daily, either in an automated way via the wearables or self-reported by the end-users through the App; and b) the registration to and training on the BETTER4U Intervention Platform of the "implementers" for a total duration of one week (7 days), during which they will be asked to test the platform's functionalities using synthetic data. The implementers will also be provided with the wearables and the App (similarly to the end-users) for one week only to allow collection of additional data that will help verify the accuracy of the algorithms in the gathered data from the wearables/monitoring tools regarding BCBIs and LEIs.

Overall, the outcomes and the findings of the Pilot Study will be used to further refine, optimize, and adjust the tools for the BETTER4ALL RCT, according to the feedback received by both end-users' and implementers' perspectives.

The 2 groups in the trial

End-users - General Population ParticipantsOther group
Adults from the general population (aged 18- 65 years, with normal weight or overweight/obesity) who will use the BETTER4U mobile application and a wearable smartwatch for 21 days. During this period, lifestyle behaviors and living environment indicators will be recorded daily, either automatically via the wearable or through self-reports via the app.
Treatment: BETTER4U Mobile App and Wearable Use (End-User Group)
Implementers - Healthcare ProfessionalsOther group
Healthcare professionals (e.g., medical doctors, dietitians/nutritionists, psychologists, nurses) who will use the BETTER4U Intervention Platform, mobile application, and wearable smartwatch for 7 days. During this period, they will interact daily with the Intervention Platform using synthetic data to evaluate its functionalities and usability. Additionally, they will wear the smartwatch and use the app to record lifestyle behavior and living environment indicators (LEIs). They will provide structured "growth truth" data (e.g., transportation mode, activity levels, sleep quality) to validate the accuracy of the AI algorithms. Their feedback will help optimize their intervention delivery system and AI-based tools before large-scale deployment.
Treatment: BETTER4U Intervention Platform Testing (Implementer Group)