A study on a weight loss app for Indonesian adults living with obesity

ISRCTN	ISRCTN45333971
DOI	https://doi.org/10.1186/ISRCTN45333971
Sponsor	University of Leeds
Funder	Lembaga Pengelola Dana Pendidikan

Submission date: 12/06/2026
Registration date: 12/06/2026
Last edited: 30/07/2026

Recruitment status: No longer recruiting
Overall study status: Ongoing
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Obesity is an important and growing health concern among adults in Indonesia. Mobile phone apps may be a convenient way to support people who want to manage their weight by improving diet, physical activity, and self-monitoring. This study will test DietducateX, an evidence-based weight-loss mobile app. The main aim is to find out whether it is feasible and acceptable to use DietducateX in a future larger study. The study will also give an early indication of whether DietducateX may help with weight loss, body composition, and diet quality.

Who can participate?
Adults aged 18 years or older who live in Jember Regency, Indonesia; have a BMI of 27 kg/m² or higher; are in good general health; can read and write in Bahasa Indonesia; and own or have access to a smartphone that can run the study apps

What does the study involve?
After eligibility checks, written consent, and baseline measurements, participants will be randomly allocated to one of two groups for 12 weeks. One group will use the full DietducateX app. The other group will use a dummy app that provides health information about topics such as nutrition, physical activity, sleep, and weight management. Researchers will measure recruitment, retention, app engagement, and acceptability. They will also measure body weight, body composition, and diet quality at the start of the study and after 12 weeks. Researchers and staff who measure outcomes will be masked to group allocation; only one independent researcher who creates randomisation will know group allocation.

What are the possible benefits and risks of participating?
Participants may learn more about weight management and healthy lifestyle behaviours. Participants in the control group will be offered access to DietducateX after the pilot trial. There may be no direct personal benefit. The risks are expected to be low, but participants may experience inconvenience from attending study visits, completing questionnaires, or using the app. Body measurements may cause minor discomfort or embarrassment. People with implanted electrical devices, significant metal implants, or pregnancy are excluded because body composition measurement using bioelectrical impedance analysis may not be suitable for them.

Where is the study run from?
The study is run from the Nutrition Care Centre (NCC), Politeknik Negeri Jember, Jember, East Java, Indonesia, with sponsorship from the University of Leeds (UK).

When is the study starting and how long is it expected to run for?
June 2026 to October 2026

Who is funding the study?
The study is funded by Lembaga Pengelola Dana Pendidikan (LPDP), also known as the Indonesia Endowment Fund for Education.

Who is the main contact?
Muhammad Iqbal, fsmi@leeds.ac.uk

Contact information

Mr Muhammad Iqbal
Public, Principal investigator, Scientific

University of Leeds
Woodhouse Lane
Leeds
LS2 9JT
United Kingdom

ORCID ID	0000-0003-1986-5330
Phone	+44 (0)7776613133
Email	fsmi@leeds.ac.uk

Study information

Primary study design	Interventional
Allocation	Randomized controlled trial
Masking	Blinded (masking used)
Control	Active
Assignment	Parallel
Purpose	Treatment
Scientific title	Feasibility and acceptability of DietducateX, an evidence-based weight-loss mobile app, compared with a dummy app among Indonesian adults with obesity: a single-blind, randomised, controlled, parallel-group pilot trial
Study acronym	DietducateX
Study objectives	1. To assess the feasibility of recruiting and retaining Indonesian adults with obesity in a 12-week pilot randomised controlled trial of DietducateX compared with a dummy app. 2. To assess participant engagement with DietducateX over 12 weeks, including whether participants use the app at least twice per week on average. 3. To assess the acceptability of DietducateX at 12 weeks, including whether at least 70% of participants rate the app as acceptable. 4. To provide preliminary exploratory estimates of the effect of DietducateX compared with a dummy app on body weight, body composition, and diet quality/dietary intake at 12 weeks.
Ethics approval(s)	1. Approved 22/12/2025, Research Ethics Committee for Business, Environment, Social Sciences (BESS+ FREC), University of Leeds (Governance and Compliance, 11-14 Blenheim Terrace, University of Leeds, Leeds, LS2 9HZ, United Kingdom; +44 (0)113 2431751; ResearchEthics@leeds.ac.uk), ref: BESS+ FREC 3238 2. Approved 17/06/2025, The Ethics Committee of the State Polytechnic of Jember (Komisi Etik Penelitian Politeknik Negeri Jember) (Mastrip PO Box 164, Jember, 68101, Indonesia; +62 (0)331 333531; polije@ac.id), ref: 0755/PL17.4/PG/2025
Health condition(s) or problem(s) studied	Overweight and obesity
Intervention	Participants will be recruited through digital flyers shared through social media, online communities, local influencers, and the existing DietducateX user email list. Interested individuals will complete an online eligibility screening form. Those who appear eligible will be invited to attend a baseline appointment at the Nutrition Care Centre (NCC), Politeknik Negeri Jember, Jember, East Java, Indonesia. At this visit, participants will complete a second eligibility screening, provide written informed consent, and complete baseline assessments. Eligible participants will be randomly assigned in a 1:1 ratio to either the DietducateX group or the dummy app control group for 12 weeks. The randomisation list will be generated using sealedenvelope.com. One of the independent researchers may be aware of group allocation, but other researchers and staff measuring outcomes will remain masked to group allocation. Intervention group: Participants will receive full access to DietducateX, an evidence-based weight loss app. DietducateX includes progress reports, self-monitoring, reminders, weekly educational texts, gamification, and monitoring by an expert. Participants will use the app for 12 weeks. Control group: Participants will receive access to a dummy app that provides passive health information/messages about physical activity, nutrition, sleep, and weight management through informative articles and a BMI calculator. All participants will complete outcome assessments at baseline (week 0) and post-intervention (week 12). The DietducateX app will be made available to control participants after the pilot trial.
Intervention type	Behavioural
Primary outcome measure(s)	Recruitment rate measured using the number randomised divided by the target sample size of 66, multiplied by 100, at the end of recruitment Retention rate measured using the percentage of randomised participants who complete the post-intervention at post-intervention (week 12) Participant engagement measured using automatically recorded app usage data, summarised as average app use per participant per week, at the 12-week intervention period Acceptability measured using the User Version Mobile App Rating Scale (uMARS) and the percentage of participants rating the app as acceptable at post-intervention (week 12)
Key secondary outcome measure(s)	Body weight measured using a digital weighing scale/BIA device at baseline (week 0) and post-intervention (week 12) Body composition measured using bioelectrical impedance analysis (BIA), including body fat mass, percentage body fat, skeletal muscle mass, fat-free mass, fluid balance, segmental analysis, basal metabolic rate, and visceral fat level, at baseline (week 0) and post-intervention (week 12) Diet quality measured using the Diet Quality Questionnaire (DQQ) at baseline (week 0) and post-intervention (week 12) Dietary intake recorded measured using app-based dietary records, including energy intake, macronutrients, and micronutrients, at the 12-week intervention period
Completion date	09/10/2026

Eligibility

Participant type(s)
Age group	Mixed
Lower age limit	18 Years
Upper age limit	100 Years
Sex	All
Target sample size at registration	66
Total final enrolment	66
Key inclusion criteria	1. Adult aged 18 years or older 2. Body mass index (BMI) of 27 kg/m² or higher 3. Residing in Jember, Indonesia 4. Good general health 5. Able to read and write in bahasa Indonesia 6. Owns and has access to a smartphone capable of running the required applications
Key exclusion criteria	1. Individuals with clinical dietary restrictions 2. Individuals implanted electrical devices (e.g., pacemakers, defibrillators) 3. Significant metal implants 4. Pregnancy
Date of first enrolment	25/06/2026
Date of final enrolment	06/07/2026

Locations

Countries of recruitment

Indonesia

Study participating centre

Politeknik Negeri Jember

Mastrip PO BOX 164, Jember - Jawa Timur- Indonesia;
Jember
68101
Indonesia

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan	An anonymised participant-level dataset, data dictionary, and relevant analysis materials will be deposited in a suitable research data repository, such as Zenodo, Figshare, and Research Data Leeds Repository, after completion of the study and publication of the main results. Direct identifiers will be removed before sharing. Data will be retained for more than 10 years. Access and reuse will follow the consent, ethics approval, and repository requirements applicable to the study.

Individual participant data (IPD) Intention to share

Yes

IPD sharing plan

An anonymised participant-level dataset, data dictionary, and relevant analysis materials will be deposited in a suitable research data repository, such as Zenodo, Figshare, and Research Data Leeds Repository, after completion of the study and publication of the main results. Direct identifiers will be removed before sharing. Data will be retained for more than 10 years. Access and reuse will follow the consent, ethics approval, and repository requirements applicable to the study.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Protocol (other)		19/06/2025	30/07/2026	No	No

Editorial Notes

30/07/2026: The following changes were made to the study record:
1. The date of final enrolment was changed from 10/07/2026 to 06/07/2026.
2. The completion date was changed from 02/10/2026 to 09/10/2026.
3. Final enrolment number and protocol link added.
12/06/2026: Study's existence confirmed by the Research Ethics Committee for Business, Environment, Social Sciences (BESS+ FREC), University of Leeds.