Body Mass Index (BMI)GENEROOSNCT06092372
The Role of Genetics in Weight Loss
A study testing Diet intervention program in people with Body Mass Index (BMI), run by University of Helsinki at 1 site in Finland.
Trial summary
The prevalence of both overweight and obesity is increasing at an alarming rate worldwide. In fact, it is estimated that 2.16 billion adults (38%) will be overweight and 1.12 billion adults (20%) will be obese by 2030. Read more about this study
- Who is it for?
- Ages 35 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Body Mass Index (BMI)
- What is being tested?
- Diet intervention program
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 223 participants
- Where
- 1 siteFinland
- Study dates
- 2 Oct 2023to 16 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 30-65 years old
- body mass index (BMI) of 25-35
- participants with genetic data available
- participants with a valid recontacting informed consent to their biobank
Who cannot join
- diagnosis of type I and II Diabetes Mellitus
- history of bariatric surgery
- diagnosis of schizophrenia and intellectual disability
- diagnosis of dementia and Parkinson's
- diagnosis of visual impairment
- diagnosis of multiple sclerosis
- pregnancy or breastfeeding during enrollment screening
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Role of Genetics in Weight Loss: a Randomized Diet Intervention Study in Individuals With High or Low Genetic Risk for Obesity (GENEROOS Study)
The prevalence of both overweight and obesity is increasing at an alarming rate worldwide. In fact, it is estimated that 2.16 billion adults (38%) will be overweight and 1.12 billion adults (20%) will be obese by 2030. Among other risk factors (e.g., environmental, behavioral, and medical), genetics holds an important role. Genome-wide association studies have discovered hundreds of loci associated with body mass index (BMI). Polygenic scores (PS) are generated from a combination of millions of genetic variants that are associated with BMI. Several diet intervention studies aimed at reducing body weight in overweight and obese individuals. However, the effect of genetic background on the effectiveness of diet interventions is largely unknown. To our knowledge, the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) trial is the only prospective study that has been designed to evaluate the effect of genotypes in modifying the impact of a healthy low-fat diet vs a healthy low-carbohydrate diet on weight change, but this study did not consider PS.
The aim of our study is to determine whether BMI PS impacts the effectiveness of dietary intervention in reducing BMI among individuals with elevated BMI.
Read more
To achieve this, the investigators will leverage the unique opportunity provided by the Finnish biobanks research environment to re-contact 1200 individuals who have extreme genetic predisposition for high/low BMI as measured by a PS for BMI and evaluate how a randomized diet intervention effect varies between the two extreme groups. In brief, the investigators will invite overweight (25-35 BMI) individuals with very high (Top 5%; n=600) and very low (Bottom 5%; n=600) PS for BMI. Half of the participants in each group will be subsequently randomized to enroll in a dietary/lifestyle coaching intervention program or the placebo group and not receive any dietary advice or information. All participants will be asked to answer an online questionnaire and provide a fasting blood sample at baseline and at the end of the study.
This well-powered prospective study leverages the unique opportunity to re-contact individuals at the extremes of BMI PS from a large pool of individuals with already available genetic information. This study will determine whether BMI PS can be used to identify overweight and obese individuals who are more likely to succeed in a reduced-energy dietary intervention, which will assist our efforts in curbing the overweight and obesity epidemic.
- Conditions
- Body Mass Index (BMI)
- Being tested
- Diet intervention program
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diet intervention programBehavioural
Participants will get 5 meals/day based on their calorie needs minus 500 kcal/day less than their daily calorie expenditure. All meals will be tracked via a mobile application, including any meals outside the recommended food plan. The calories will be calculated based on the information provided.
To calculate the calories burned from any activities, all participants in the diet intervention arm will get an activity tracking device. The first calorie level is calculated based on the information in the registration form: age, height, weight, gender, and personal view of the daily activity. After that, and once the activity tracker is synced to the program, the calorie level is calculated based on the 7-day average calories burned.
The external diet intervention provider will be blinded to whether the study participants belong to the top or bottom 5% of the polygenic score for BMI.
| Study group | Role | What they receive |
|---|---|---|
| Control | No intervention | Participants in the control group will be asked to fill out online surveys and book appointments for blood sample collection and weight measurements at the beginning and at the end of the study. In addition, participants will be asked to report their weight two more times during the study (in months 2 and 4) with an online survey that will be sent via the MyBiobank portal. The participation in the study ends with another personal visit to the clinic for blood sampling and weight measurement six months after registration. No other personal advice or support is provided to this group. |
| Diet Intervention | Experimental | Participants in the diet intervention group will be asked to fill out online surveys and book appointments for blood sample collection and weight measurements at the beginning and at the end of the study. After visiting the clinic for the first time, each participant will be contacted to start a diet coaching program and to obtain an activity tracking device. In addition, each participant will be asked to report their weight two more times during the study (in months 2 and 4) with an online survey that will be sent to them via the online portal of the study (OmaBiopankki portal). The study participation ends with another personal visit to the clinic for blood sampling and weight measurement six months after registration. Receives: Behavioral: Diet intervention program |
What is being measured
The primary outcome is the main question the study is designed to answer.
Interaction between the top and bottom 5th percentile of the polygenic score (PS) distribution for body mass index (BMI) distribution and BMI reduction
The investigators will test the interaction between the BMI PS groups (i.e., top and bottom 5% PS for the BMI groups) and intervention groups (i.e. diet intervention and control) in their association with BMI differences between baseline and after 6 months (ΔBMI). More specifically, the investigators will test this interaction using a linear model such as ΔBMI ~ intervention_group*BMI_PS_group + age + age^2 + sex. In other words, the investigators will assess whether the effect of diet intervention on BMI reduction differs by the polygenic score for BMI among participants.
BMI will be calculated based on the lab-measured body weight and height of each participant and according to the BMI calculation formula (i.e., weight in kilograms divided by height in meters squared).
Measured: Six months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Oct 2023
- Study start2 Oct 2023
- Primary completion8 Nov 2024
- Study completion16 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Body Mass Index (BMI)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 223 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Helsinki
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Andrea Ganna, University of Helsinki
- Investigators
- Andrea Ganna, Principal investigator, University of Helsinki
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06092372
- Sponsor's protocol ID
- 945733HUS5832022
- Acronym
- GENEROOS
- Status last verified
- Jan 2026
- First submitted
- 11 Oct 2023
- Last updated
- 29 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Access to individual participant data can be obtained via FinnGenious (https://site.fingenious.fi/en/) and via study PI
Publications
Rodosthenous RS, Viiri LE, Carson AM, Cajuso T, Corbetta A, Jones S, Brenna E, FinnGen, Makkonen E, Virolainen M, Korkeala N, Widen E, Ripatti S, Ganna A. Dietary intervention and BMI reduction in individuals at the extremes of genetic predisposition to higher BMI: a randomized controlled trial. Nat Commun. 2026 Jul 13. doi: 10.1038/s41467-026-75224-0. Online ahead of print.
PubMed 42443177
Study at a glance
From the registry record, last updated by the sponsor on 29 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Genetics in Weight Loss: a Randomized Diet Intervention Study in Individuals With High or Low Genetic Risk for Obesity (GENEROOS Study)
- ClinicalTrials.gov ID
- NCT06092372
- Acronym / sponsor ID
- GENEROOS / 945733HUS5832022
- Conditions
- Body Mass Index (BMI)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 223 participants (actual)
- Lead sponsor
- University of HelsinkiUniversity, hospital or other
- Study start
- 2 Oct 2023 (actual)
- Primary completion
- 8 Nov 2024 (actual)
- Study completion
- 16 Dec 2024 (actual)
- First posted
- 23 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The prevalence of both overweight and obesity is increasing at an alarming rate worldwide. In fact, it is estimated that 2.16 billion adults (38%) will be overweight and 1.12 billion adults (20%) will be obese by 2030. Among other risk factors (e.g., environmental, behavioral, and medical), genetics holds an important role. Genome-wide association studies have discovered hundreds of loci associated with body mass index (BMI). Polygenic scores (PS) are generated from a combination of millions of genetic variants that are associated with BMI. Several diet intervention studies aimed at reducing body weight in overweight and obese individuals. However, the effect of genetic background on the effectiveness of diet interventions is largely unknown. To our knowledge, the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) trial is the only prospective study that has been designed to evaluate the effect of genotypes in modifying the impact of a healthy low-fat diet vs a healthy low-carbohydrate diet on weight change, but this study did not consider PS.
The aim of our study is to determine whether BMI PS impacts the effectiveness of dietary intervention in reducing BMI among individuals with elevated BMI.
To achieve this, the investigators will leverage the unique opportunity provided by the Finnish biobanks research environment to re-contact 1200 individuals who have extreme genetic predisposition for high/low BMI as measured by a PS for BMI and evaluate how a randomized diet intervention effect varies between the two extreme groups. In brief, the investigators will invite overweight (25-35 BMI) individuals with very high (Top 5%; n=600) and very low (Bottom 5%; n=600) PS for BMI. Half of the participants in each group will be subsequently randomized to enroll in a dietary/lifestyle coaching intervention program or the placebo group and not receive any dietary advice or information. All participants will be asked to answer an online questionnaire and provide a fasting blood sample at baseline and at the end of the study.
This well-powered prospective study leverages the unique opportunity to re-contact individuals at the extremes of BMI PS from a large pool of individuals with already available genetic information. This study will determine whether BMI PS can be used to identify overweight and obese individuals who are more likely to succeed in a reduced-energy dietary intervention, which will assist our efforts in curbing the overweight and obesity epidemic.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control | No intervention | –Participants in the control group will be asked to fill out online surveys and book appointments for blood sample collection and weight measurements at the beginning and at the end of the study. In addition, participants will be asked to report their weight two more times during the study (in months 2 and 4) with an online survey that will be sent via the MyBiobank portal. The participation in the study ends with another personal visit to the clinic for blood sampling and weight measurement six months after registration. No other personal advice or support is provided to this group. |
| Diet Intervention | Experimental | Behavioral: Diet intervention programParticipants in the diet intervention group will be asked to fill out online surveys and book appointments for blood sample collection and weight measurements at the beginning and at the end of the study. After visiting the clinic for the first time, each participant will be contacted to start a diet coaching program and to obtain an activity tracking device. In addition, each participant will be asked to report their weight two more times during the study (in months 2 and 4) with an online survey that will be sent to them via the online portal of the study (OmaBiopankki portal). The study participation ends with another personal visit to the clinic for blood sampling and weight measurement six months after registration. |
Who may qualify
- Ages
- 35 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 30-65 years old
- body mass index (BMI) of 25-35
- participants with genetic data available
- participants with a valid recontacting informed consent to their biobank
Key exclusion criteria (7 listed)
- diagnosis of type I and II Diabetes Mellitus
- history of bariatric surgery
- diagnosis of schizophrenia and intellectual disability
- diagnosis of dementia and Parkinson's
- diagnosis of visual impairment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diet intervention programParticipants will get 5 meals/day based on their calorie needs minus 500 kcal/day less than their daily calorie expenditure. All meals will be tracked via a mobile application, including any meals outside the recommended food plan. The calories will be calculated based on the information provided. To calculate the calories burned from any activities, all participants in the diet intervention arm will get an activity tracking device. The first calorie level is calculated based on the information in the registration form: age, height, weight, gender, and personal view of the daily activity. After that, and once the activity tracker is synced to the program, the calorie level is calculated based on the 7-day average calories burned. The external diet intervention provider will be blinded to whether the study participants belong to the top or bottom 5% of the polygenic score for BMI. | Behavioural | Diet Intervention |
Primary outcome
Interaction between the top and bottom 5th percentile of the polygenic score (PS) distribution for body mass index (BMI) distribution and BMI reduction
Time frame: Six months
The investigators will test the interaction between the BMI PS groups (i.e., top and bottom 5% PS for the BMI groups) and intervention groups (i.e. diet intervention and control) in their association with BMI differences between baseline and after 6 months (ΔBMI). More specifically, the investigators will test this interaction using a linear model such as ΔBMI ~ intervention_group*BMI_PS_group + age + age^2 + sex. In other words, the investigators will assess whether the effect of diet intervention on BMI reduction differs by the polygenic score for BMI among participants. BMI will be calculated based on the lab-measured body weight and height of each participant and according to the BMI calculation formula (i.e., weight in kilograms divided by height in meters squared).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jan 2026.
- Derived from this study: PubMed 42443177Rodosthenous RS, Viiri LE, Carson AM, Cajuso T, Corbetta A, Jones S, Brenna E, FinnGen, Makkonen E, Virolainen M, Korkeala N, Widen E, Ripatti S, Ganna A. Dietary intervention and BMI reduction in individuals at the extremes of genetic predisposition to higher BMI: a randomized controlled trial. Nat Commun. 2026 Jul 13. doi: 10.1038/s41467-026-75224-0. Online ahead of print.
- Individual participant dataSharing planned: No. Access to individual participant data can be obtained via FinnGenious (https://site.fingenious.fi/en/) and via study PI
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Andrea Ganna principal investigator
University of Helsinki
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Diet intervention program in people with Body Mass Index (BMI), run by University of Helsinki at 1 site in Finland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Finland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Interaction between the top and bottom 5th percentile of the polygenic score (PS) distribution for body mass index (BMI) distribution and BMI reduction (time frame: Six months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06092372, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jan 2026.