Overweight , ObesityMAPNCT07415213
Mapping Metabolic Organ Plasticity in Energy Adaptation
A study testing Calorie Restriction (CR), Time Restricted Eating (TRE) and Resistance Training (RT) in people with Overweight , Obesity and Energy Metabolism, run by Tel Aviv University at 1 site in Israel.
Trial summary
Brief Summary (Plain Language) Many people who lose weight experience a slowdown in their metabolism that is greater than expected. This response, called metabolic adaptation, makes it harder to continue losing weight or to keep weight off over time. The biological reasons for this slowdown are not fully understood. Read more about this study
- Who is it for?
- Ages 25 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Overweight , Obesity, Energy Metabolism
- What is being tested?
- Calorie Restriction (CR), Time Restricted Eating (TRE) and Resistance Training (RT)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 1 siteIsrael
- Study dates
- 3 Feb 2026to Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 25 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Sedentary men and women aged 25-60 years
- Body mass index (BMI) of 25-35 kg/m²
Who cannot join
- Participation in another exercise or weight loss program in the last 6 months
- Non-stable weight (>±5%) over the past 6 months
- Smoking within the past 6 months
- Post-menopause
- Breastfeeding
- Pregnancy or having been pregnant within the past 6 months
Show all 14Show fewer
- Contraindication for MRI scans (e.g., tattoos, intrauterine devices, permanent makeup, etc.)
- Severe cardiopulmonary disease (e.g., recent myocardial infarction or unstable angina)
- Musculoskeletal or neuromuscular impairments that preclude exercise training
- Cognitive impairments
- Other health issues, including cancer, diabetes, thyroid disease, hypertension, or chronic renal failure
- Use of drugs that affect body metabolism
- Secondary liver disease (viral, autoimmune, alcoholic, or hepatotoxic)
- Alcohol consumption above 20 g/day for women or 30 g/day for men
Trial locations and contacts
1 site in 1 country.
About this study
Brief Summary (Plain Language)
Many people who lose weight experience a slowdown in their metabolism that is greater than expected. This response, called metabolic adaptation, makes it harder to continue losing weight or to keep weight off over time. The biological reasons for this slowdown are not fully understood.
Read more
Some organs in the body, especially the liver and kidneys, use a large amount of energy even when the body is at rest. Although these organs make up only a small portion of body weight, they account for a large share of daily energy use. Changes in the size or function of these organs may play an important role in metabolic adaptation, but this has not been well studied in humans.
The purpose of this study is to understand how different lifestyle approaches affect metabolic adaptation and the size of key metabolic organs. Specifically, the study compares three common strategies:
- resistance training without calorie restriction,
- a calorie-restricted diet, and
- time-restricted eating (eating all daily food within a limited time window).
Adults with overweight will take part in one of these approaches for 10 weeks. Before and after the study period, participants will undergo advanced measurements, including magnetic resonance imaging (MRI) scans to measure liver and kidney size, tests to measure resting metabolism, and assessments of body composition. Some participants will also undergo additional testing to measure daily energy use.
By understanding how different lifestyle strategies influence metabolism and organ size, this study aims to improve knowledge about why weight loss is difficult to maintain and to support the development of more personalized approaches to long-term weight management.
Read the detailed description
Metabolic adaptation refers to a reduction in resting energy expenditure that is greater than what would be predicted from changes in body weight or body composition. This phenomenon is commonly observed during weight loss and is believed to contribute to weight regain. While metabolic adaptation is well documented, the underlying physiological mechanisms remain unclear.
Highly metabolic organs, including the liver and kidneys, consume a disproportionate amount of energy at rest. Emerging evidence suggests that reductions in the size of these organs during energy deficit states may contribute to declines in resting metabolic rate. However, few human studies have directly examined how different lifestyle interventions influence organ size and how these changes relate to metabolic adaptation.
This study is a 10-week, open-label, lifestyle intervention trial conducted in sedentary adults with overweight. Participants are assigned to one of three intervention groups: resistance training with a normal diet, calorie restriction, or time-restricted eating. All participants are supervised by qualified health professionals throughout the study.
Measurements are conducted before and after the intervention period and include gold-standard assessments of resting metabolic rate, body composition, liver and kidney volume using MRI, and hepatic fat content. A subset of participants undergoes doubly labeled water testing to assess total daily energy expenditure.
The primary goal of the study is to compare the degree of metabolic adaptation across the three lifestyle strategies. Secondary objectives include evaluating changes in liver and kidney volume and determining how these organ-level changes contribute to changes in metabolism. The study is designed to provide mechanistic insight into how exercise- and diet-based interventions influence energy regulation at the organ level.
The results of this research are expected to advance understanding of metabolic adaptation in humans and may help inform more effective and individualized strategies for weight loss and long-term weight maintenance.
- Conditions
- Overweight , Obesity, Energy Metabolism
- Being tested
- Calorie Restriction (CR), Time Restricted Eating (TRE), Resistance Training (RT)
- Keywords
- Metabolic adaptation, Energy expenditure, Metabolic organs, lifestyle modalities, weight loss
- Medical subject headings
- Overweight, Obesity, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Calorie Restriction (CR)Behavioural
Participants in the CR group will be asked to stay on an energy deficit of 500 Kcal/day, based on their RMR measurement. This intervention is designed to optimize the likelihood that a substantial degree of CR is achieved through a variety of nutritional and behavioural strategies. The CR intervention will be conceptualized as an intensive behavioural approach coupled with dietary modifications and daily self-monitoring of calories, designed to promote adherence to long-term CR. Each participant will be provided with an individualized CR prescription for ~25% CR from baseline ad libitum energy intake as determined by intake as determined by their personalized RMR.
Time Restricted Eating (TRE)Behavioural
Participants in the TRE groups will be instructed at weekly personal meetings to consume all meals between 10am to 6pm, and to avoid consumption of food or caloric drinks during the fasting period (8 h eating window with 16 h of fasting).
Resistance Training (RT)Behavioural
The participants who are assigned to the RT groups will perform supervised and monitored RT three times a week for a duration of 10 weeks. During the first two weeks of training, participants will be familiarized with RT exercises to ensure adoption, adherence, and correction of their technique. Additionally, intensity will increase from 40-60% 1-repetition maximum (1RM). Guided training sessions will start with the evaluation of 10 RM. Participants will train for 60 minutes, 3 times a week, using a full-body workout with nine exercises for a major muscle group. The exercise sessions will last ~60 minutes and will include a five-minute warmup, followed by 50 minutes of resistance exercises, including nine upper- and lower-body exercises using weight-lifting machines. In every training session, subjects will complete between 8-12 repetitions. If subjects successfully finish three sets of 12 reps, extra weight will be added to maintain an increased intensity. The r
| Study group | Role | What they receive |
|---|---|---|
| Calorie Restriction | Experimental | energy deficit of 500 Kcal/day Receives: Behavioral: Calorie Restriction (CR) |
| Time Restricted Eating | Experimental | fasting period (8 h eating window with 16 h of fasting). Receives: Behavioral: Resistance Training (RT) |
| Resistance Training | Experimental | Participants will train for 60 minutes, 3 times a week, using a full-body workout with nine exercises for a major muscle group. Receives: Behavioral: Time Restricted Eating (TRE) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Metabolic Adaptation
Change in metabolic adaptation, defined as the difference between predicted resting metabolic rate and measured resting metabolic rate.
Measurement:
Resting metabolic rate measured by indirect calorimetry and predicted from body composition-based equations.
Measured: Baseline to 10 weeks
Secondary outcomes (4)
Change in Resting Metabolic Rate (RMR)
Change in resting metabolic rate.
Measurement:
Resting metabolic rate (kcal/day) measured by indirect calorimetry.
Measured: Baseline to 10 weeks
Change in Liver Volume
Change in liver volume following the intervention.
Measurement:
Liver volume (cm³) measured by magnetic resonance imaging (MRI).
Measured: Baseline to 10 weeks
Change in Kidney Volume
Change in total kidney volume.
Measurement:
Left and right kidney volume (cm³) measured by magnetic resonance imaging (MRI).
Measured: Baseline to 10 weeks
Association Between Organ Volume Changes and Metabolic Adaptation
Relationship between changes in liver and kidney volume and changes in metabolic adaptation.
Measurement:
Correlation between MRI-derived organ volume changes and metabolic adaptation values.
Measured: Baseline to 10 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Feb 2026
- Study start3 Feb 2026
- Primary completionDec 2029 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Overweight , ObesityStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tel Aviv University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Gepner Yftach, Tel Aviv University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07415213
- Sponsor's protocol ID
- 0003858-5
- Acronym
- MAP
- Status last verified
- Feb 2026
- First submitted
- 9 Feb 2026
- Last updated
- 17 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mapping Metabolic Organ Plasticity in Energy Adaptation
- ClinicalTrials.gov ID
- NCT07415213
- Acronym / sponsor ID
- MAP / 0003858-5
- Conditions
- Overweight , Obesity, Energy Metabolism
- Keywords
- Metabolic adaptation, Energy expenditure, Metabolic organs, lifestyle modalities, weight loss
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- Tel Aviv UniversityUniversity, hospital or other
- Study start
- 3 Feb 2026 (actual)
- Primary completion
- Dec 2029 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 17 Feb 2026 (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.
Brief Summary (Plain Language)
Many people who lose weight experience a slowdown in their metabolism that is greater than expected. This response, called metabolic adaptation, makes it harder to continue losing weight or to keep weight off over time. The biological reasons for this slowdown are not fully understood.
Some organs in the body, especially the liver and kidneys, use a large amount of energy even when the body is at rest. Although these organs make up only a small portion of body weight, they account for a large share of daily energy use. Changes in the size or function of these organs may play an important role in metabolic adaptation, but this has not been well studied in humans.
The purpose of this study is to understand how different lifestyle approaches affect metabolic adaptation and the size of key metabolic organs. Specifically, the study compares three common strategies:
- resistance training without calorie restriction,
- a calorie-restricted diet, and
- time-restricted eating (eating all daily food within a limited time window).
Adults with overweight will take part in one of these approaches for 10 weeks. Before and after the study period, participants will undergo advanced measurements, including magnetic resonance imaging (MRI) scans to measure liver and kidney size, tests to measure resting metabolism, and assessments of body composition. Some participants will also undergo additional testing to measure daily energy use.
By understanding how different lifestyle strategies influence metabolism and organ size, this study aims to improve knowledge about why weight loss is difficult to maintain and to support the development of more personalized approaches to long-term weight management.
Detailed description
Metabolic adaptation refers to a reduction in resting energy expenditure that is greater than what would be predicted from changes in body weight or body composition. This phenomenon is commonly observed during weight loss and is believed to contribute to weight regain. While metabolic adaptation is well documented, the underlying physiological mechanisms remain unclear.
Highly metabolic organs, including the liver and kidneys, consume a disproportionate amount of energy at rest. Emerging evidence suggests that reductions in the size of these organs during energy deficit states may contribute to declines in resting metabolic rate. However, few human studies have directly examined how different lifestyle interventions influence organ size and how these changes relate to metabolic adaptation.
This study is a 10-week, open-label, lifestyle intervention trial conducted in sedentary adults with overweight. Participants are assigned to one of three intervention groups: resistance training with a normal diet, calorie restriction, or time-restricted eating. All participants are supervised by qualified health professionals throughout the study.
Measurements are conducted before and after the intervention period and include gold-standard assessments of resting metabolic rate, body composition, liver and kidney volume using MRI, and hepatic fat content. A subset of participants undergoes doubly labeled water testing to assess total daily energy expenditure.
The primary goal of the study is to compare the degree of metabolic adaptation across the three lifestyle strategies. Secondary objectives include evaluating changes in liver and kidney volume and determining how these organ-level changes contribute to changes in metabolism. The study is designed to provide mechanistic insight into how exercise- and diet-based interventions influence energy regulation at the organ level.
The results of this research are expected to advance understanding of metabolic adaptation in humans and may help inform more effective and individualized strategies for weight loss and long-term weight maintenance.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Calorie Restriction | Experimental | Behavioral: Calorie Restriction (CR)energy deficit of 500 Kcal/day |
| Time Restricted Eating | Experimental | Behavioral: Resistance Training (RT)fasting period (8 h eating window with 16 h of fasting). |
| Resistance Training | Experimental | Behavioral: Time Restricted Eating (TRE)Participants will train for 60 minutes, 3 times a week, using a full-body workout with nine exercises for a major muscle group. |
Who may qualify
- Ages
- 25 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Sedentary men and women aged 25-60 years
- Body mass index (BMI) of 25-35 kg/m²
Key exclusion criteria (14 listed)
- Participation in another exercise or weight loss program in the last 6 months
- Non-stable weight (>±5%) over the past 6 months
- Smoking within the past 6 months
- Post-menopause
- Breastfeeding
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 |
|---|---|---|
| Calorie Restriction (CR)Participants in the CR group will be asked to stay on an energy deficit of 500 Kcal/day, based on their RMR measurement. This intervention is designed to optimize the likelihood that a substantial degree of CR is achieved through a variety of nutritional and behavioural strategies. The CR intervention will be conceptualized as an intensive behavioural approach coupled with dietary modifications and daily self-monitoring of calories, designed to promote adherence to long-term CR. Each participant will be provided with an individualized CR prescription for ~25% CR from baseline ad libitum energy intake as determined by intake as determined by their personalized RMR. | Behavioural | Calorie Restriction |
| Time Restricted Eating (TRE)Participants in the TRE groups will be instructed at weekly personal meetings to consume all meals between 10am to 6pm, and to avoid consumption of food or caloric drinks during the fasting period (8 h eating window with 16 h of fasting). | Behavioural | Resistance Training |
| Resistance Training (RT)The participants who are assigned to the RT groups will perform supervised and monitored RT three times a week for a duration of 10 weeks. During the first two weeks of training, participants will be familiarized with RT exercises to ensure adoption, adherence, and correction of their technique. Additionally, intensity will increase from 40-60% 1-repetition maximum (1RM). Guided training sessions will start with the evaluation of 10 RM. Participants will train for 60 minutes, 3 times a week, using a full-body workout with nine exercises for a major muscle group. The exercise sessions will last ~60 minutes and will include a five-minute warmup, followed by 50 minutes of resistance exercises, including nine upper- and lower-body exercises using weight-lifting machines. In every training session, subjects will complete between 8-12 repetitions. If subjects successfully finish three sets of 12 reps, extra weight will be added to maintain an increased intensity. The r | Behavioural | Time Restricted Eating |
Primary outcome
Change in Metabolic Adaptation
Time frame: Baseline to 10 weeks
Change in metabolic adaptation, defined as the difference between predicted resting metabolic rate and measured resting metabolic rate. Measurement: Resting metabolic rate measured by indirect calorimetry and predicted from body composition-based equations.
4 secondary outcomes
Change in Resting Metabolic Rate (RMR)
Time frame: Baseline to 10 weeks
Change in Liver Volume
Time frame: Baseline to 10 weeks
Change in Kidney Volume
Time frame: Baseline to 10 weeks
Association Between Organ Volume Changes and Metabolic Adaptation
Time frame: Baseline to 10 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Feb 2026.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Calorie Restriction (CR), Time Restricted Eating (TRE) and Resistance Training (RT) in people with Overweight , Obesity and Energy Metabolism, run by Tel Aviv University at 1 site in Israel.
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 2 inclusion and 14 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: under way, not looking for participants, as of the sponsor's last update on 17 Feb 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 Israel. 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?
This study is still under way. Results are not available in the source record yet.
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?
Change in Metabolic Adaptation (time frame: Baseline to 10 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 17 Feb 2026.