ObesityPhase 3NCT00073242
Low-Dose Leptin and the Formerly-Obese
A Phase 3 study testing Leptin, Dietary modification and T3 repletion in people with Obesity, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
Our previous studies have demonstrated that there is substantial metabolic opposition to the maintenance of an altered body weight. Leptin is a protein secreted by fat cells and the circulating concentrations of leptin are directly proportional to fat mass. Read more about this study
- Who is it for?
- Ages 19 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- Leptin, Dietary modification and T3 repletion
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 31 participants
- Where
- 1 siteUnited States
- Study dates
- Jul 2000to Jul 2015
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 19 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Healthy
Trial locations and contacts
1 site in 1 country.
United States1 site
Columbia Presbyterian Medical Center
New York, New York, 10032
About this study
Official title: Effects of Low-Dose Leptin on the Metabolic/Behavioral Phenotypes of the Formerly-Obese
Our previous studies have demonstrated that there is substantial metabolic opposition to the maintenance of an altered body weight. Leptin is a protein secreted by fat cells and the circulating concentrations of leptin are directly proportional to fat mass. Leptin-deficiency is associated with severe obesity in rodents and in humans and the obesity is relieved by leptin administration. These studies examine the hypothesis that some of this metabolic opposition cto the maintenance of an altered body weight can be relieved by restoring circulating concentrations of the hormone leptin to the same range as at usual body weight in subjects who are maintaining a reduced body weight. The basic design of this study is to observe subjects at a 10% reduced body weight and then again at that reduced body weight while receiving physiological leptin or T3 supplementation.
Read the detailed description
We demonstrated a substantial metabolic resistance to maintenance of altered body weight. Leptin is secreted by fat cells in circulating concentrations that are directly proportional to fat mass. Leptin-deficiency is associated with severe obesity in rodents and in humans and the obesity is relieved by leptin administration. These studies examine the hypothesis that some of this metabolic opposition cto the maintenance of an altered body weight can be relieved by restoring circulating concentrations of the hormone leptin to the same range as at usual body weight in subjects who are maintaining a reduced body weight. The basic design of this study is to observe subjects at a 10% reduced body weight and then again at that reduced body weight while receiving physiological leptin or T3 supplementation.
- Conditions
- Obesity
- Being tested
- Leptin, Dietary modification, T3 repletion
- Keywords
- leptin, obesity
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LeptinDrug
Also called no other names
leptin administration
Dietary modificationBehavioural
Also called no other name
Subjects lose 10% of body weight via dietary restriction
T3 repletionDrug
Also called no other name
administer T3
| Study group | Role | What they receive |
|---|---|---|
| leptin repletion | Experimental | Repletion of leptin following weight loss induced by dietary modification. Receives: Drug: Leptin; Behavioral: Dietary modification |
| T3 repletion | Experimental | Repletion of T3 following weight loss induced by dietary modification. Receives: Behavioral: Dietary modification; Drug: T3 repletion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total Energy Expenditure (TEE)
Total 24-hour energy expenditure was determined by caloric titration. At the reduced-weight repletion condition, TEE was calculated from weight-maintenance caloric intake adjusted for changes in body energy stores during the treatment period.
Measured: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Secondary outcomes (4)
Resting Energy Expenditure (REE)
Resting energy expenditure was measured by indirect calorimetry using a hood calorimeter at initial body weight, after 10% weight loss during placebo treatment, and after 10% weight loss during the repletion condition.
Measured: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Non-Resting Energy Expenditure (NREE)
Non-resting energy expenditure was calculated as total energy expenditure minus resting energy expenditure and the thermic effect of feeding: NREE = TEE - (REE + TEF). NREE was assessed at initial weight, after 10% weight loss during placebo treatment, and after 10% weight loss during the repletion condition.
Measured: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Urinary Norepinephrine (24-hour Excretion)
Urinary Norepinephrine (24-hour excretion)
Measured: Initial Wt; 10% Wt Loss + placebo; 10% Wt Loss + repletion
Urinary Epinephrine (24-hour Excretion)
24-hour urinary epinephrine excretion measured at initial weight and after 10% weight loss during placebo and repletion conditions.
Measured: Initial Wt; 10% Wt Loss + Placebo; 10% Wt Loss + Repletion (5 weeks each condition)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Nov 2003 (estimated)
- Study startJul 2000
- Primary completionJul 2015
- Study completionJul 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The sponsor's other registered studies.
- 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 3
- Primary purpose
- Health services research
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 31 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00073242
- Sponsor's protocol ID
- 9631(completed)
- Status last verified
- Oct 2026
- First submitted
- 18 Nov 2003
- Last updated
- 27 Oct 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 27 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Low-Dose Leptin on the Metabolic/Behavioral Phenotypes of the Formerly-Obese
- ClinicalTrials.gov ID
- NCT00073242
- Acronym / sponsor ID
- 9631(completed)
- Conditions
- Obesity
- Keywords
- leptin, obesity
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 31 participants (actual)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- Jul 2000 (actual)
- Primary completion
- Jul 2015 (actual)
- Study completion
- Jul 2015 (actual)
- First posted
- 19 Nov 2003 (estimated)
- Results
- Posted 27 Oct 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Our previous studies have demonstrated that there is substantial metabolic opposition to the maintenance of an altered body weight. Leptin is a protein secreted by fat cells and the circulating concentrations of leptin are directly proportional to fat mass. Leptin-deficiency is associated with severe obesity in rodents and in humans and the obesity is relieved by leptin administration. These studies examine the hypothesis that some of this metabolic opposition cto the maintenance of an altered body weight can be relieved by restoring circulating concentrations of the hormone leptin to the same range as at usual body weight in subjects who are maintaining a reduced body weight. The basic design of this study is to observe subjects at a 10% reduced body weight and then again at that reduced body weight while receiving physiological leptin or T3 supplementation.
Detailed description
We demonstrated a substantial metabolic resistance to maintenance of altered body weight. Leptin is secreted by fat cells in circulating concentrations that are directly proportional to fat mass. Leptin-deficiency is associated with severe obesity in rodents and in humans and the obesity is relieved by leptin administration. These studies examine the hypothesis that some of this metabolic opposition cto the maintenance of an altered body weight can be relieved by restoring circulating concentrations of the hormone leptin to the same range as at usual body weight in subjects who are maintaining a reduced body weight. The basic design of this study is to observe subjects at a 10% reduced body weight and then again at that reduced body weight while receiving physiological leptin or T3 supplementation.
Study design
- Primary purpose
- Health services research
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| leptin repletion | Experimental | Drug: Leptin, Behavioral: Dietary modificationRepletion of leptin following weight loss induced by dietary modification. |
| T3 repletion | Experimental | Behavioral: Dietary modification, Drug: T3 repletionRepletion of T3 following weight loss induced by dietary modification. |
Who may qualify
- Ages
- 19 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
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 |
|---|---|---|
| LeptinAlso: no other namesleptin administration | Drug | leptin repletion |
| Dietary modificationAlso: no other nameSubjects lose 10% of body weight via dietary restriction | Behavioural | T3 repletion, leptin repletion |
| T3 repletionAlso: no other nameadminister T3 | Drug | T3 repletion |
Primary outcome
Total Energy Expenditure (TEE)
Time frame: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Total 24-hour energy expenditure was determined by caloric titration. At the reduced-weight repletion condition, TEE was calculated from weight-maintenance caloric intake adjusted for changes in body energy stores during the treatment period.
4 secondary outcomes
Resting Energy Expenditure (REE)
Time frame: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Non-Resting Energy Expenditure (NREE)
Time frame: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.
Urinary Norepinephrine (24-hour Excretion)
Time frame: Initial Wt; 10% Wt Loss + placebo; 10% Wt Loss + repletion
Urinary Epinephrine (24-hour Excretion)
Time frame: Initial Wt; 10% Wt Loss + Placebo; 10% Wt Loss + Repletion (5 weeks each condition)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Oct 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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 Phase 3 study testing Leptin, Dietary modification and T3 repletion in people with Obesity, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
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 27 Oct 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 United States. 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.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Oct 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Total Energy Expenditure (TEE) (time frame: At initial body weight; after 10% weight loss during placebo treatment; and after 10% weight loss during the 5-week repletion treatment period.). 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 27 Oct 2026.