An observational study in Obesity and Healthy Volunteers, sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Recruiting at 1 site in United States. Open to participants aged 18 Years to 100 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-28.
Sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Observational
Among 104 studies in Obesity by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — 12 open to participants now, 13 under way, none of them phase 3. Obesity · National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Among the 104 studies in Obesity by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), this one is the 3rd largest by planned enrollment of the 31 observational ones that give a count, is one of 7 that started in 2007, is one of 31 observational ones, and was the 52nd registered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
Browse Obesity studies →12 of the 104 studies in Obesity by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) are open now, in 1 country. Recruiting first, the newest first:
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Sites in United States
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Sites in United States
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Sites in United States
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Sites in United States
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Sites in United States
By country, each count listing its studies:
Of the 1,336 Obesity studies recruiting now, 377 (28%) set no upper age limit and 856 (64%) stop at 75 or younger; 168 take children under 18; 491 take healthy volunteers.
This study: 18 Years to 100 Years · all sexes · healthy volunteers too.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
104 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 6 · Phase 2 22 · Phase 3 6 · Phase 4 1
First in 1983; this study’s year is marked. 7 started in 2007.
This study's planned enrollment of 2,000 is above the median of 114 across 2,154 observational studies indexed under Obesity.
Median enrollment 100 across the 66 interventional studies, 144 across the 31 observational. Of the 88 that completed or were terminated, 10 (11%) have results posted.
This tab as a report to print or save as PDF → With an account.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) is the lead sponsor of 538 studies on the registry; 55 are open to participants now.
Of its 80 completed or terminated interventional studies of FDA-regulated products, 51 (64%) have results posted.
5 of the studies in Obesity by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06690294National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Assessing the Impact of Perceptions of Unpredictability on Objective Measures of Food Consumption and Metabolism | 2027-01-30 |
| NCT00739362National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Effects of Brain Stimulation on Food Intake and Behavioral Weight Loss Treatment | 2027-01-31 |
| NCT06044935National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Effect of Nicotinamide Riboside on Ketosis, Fat Oxidation & Metabolic Rate | 2027-01-31 |
| NCT05545306National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The Effects of Increasing Caloric Intake on Diet-Induced Thermogenesis and 24h Energy Expenditure | 2027-02-02 |
| NCT06223555National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Variability In Mixed Meal Tests: Fixed Versus Adjusted to Energy Needs Caloric Dose | 2027-06-30 |
Among the 104 studies in Obesity by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), from their registry updates:
This tab as a report to print or save as PDF → With an account.
This study will describe the phenotype (physical and behavioral traits) of overweight and obese people. It will characterize the hormones, metabolism, food preferences, fitness and physical activity levels, sleep patterns and thought processes in people with and without weight problems. Genetic material will be collected for studies of the internal codes that influence body weight.
People over 18 years of age from all weight categories (lean, overweight, obese) who are reasonably healthy may be eligible for this study. Participants undergo the following tests and procedures:
Although complex metabolic, hormonal, and neural networks operate to control body weight, obesity is in most cases, the result of over-feeding and inactivity. In most obese patients, patterns of fundamental behavior determine the success or failure of weight loss interventions. Behavior is controlled to some degree by conscious decision making and is influenced by signals from the integrated networks involved in body weight regulation. The contributions of behavior, environment, socioeconomic status, physiology and genetics assure that no single therapeutic regimen will be successful in all obese individuals. In order to explore the factors that impede weight loss and result in weight regain, the obese phenotype and its variants must be defined. The purpose of this study is to detail hormonal, metabolic, cognitive and behavioral traits across the spectrum of weight categories utilizing the state-of the-art facilities of the Metabolic Units at the Mark O. Hatfield Clinical Research Center, NIH. Genetic material will be banked for analysis of phenotypic subgroups as they emerge.
Patients over the age of 18 are eligible for this study. While childhood obesity is an important public health issue, the variables of growth and hormonal controls will be delineated in separate studies. Over-weight and obese patients are encouraged to participate in as full an evaluation as feasible. Lean individuals will be recruited to create a normative database for body composition (dual energy x-ray absortiometry, air displacement plethysmography), energy expenditure (resting energy expenditure, 24h respiratory chamber and doubly labeled water) and other techniques used to study traits of importance. The study will be conducted in both the inpatient and outpatient setting and can include evaluation of hormones, diurnal variation, sleep, eating behavior and taste perception, physical fitness, psychological and neurocognitive functioning. Importantly, this protocol is the means by which pilot data are obtained to develop novel approaches and hypotheses for studying obesity and its associated traits.
men and women 18 years old and over with BMI > 30 BMI > 25 and \< 30 BMI > 18.5 and \< 25
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Obese subjects:
Overweight subjects:
Control subjects (may be matched for age, sex and years of education):
EXCLUSION CRITERIA:
Additional exclusion for lean control subjects:
The NIH Patient Recruitment and Public Liaison Office will receive inquiries from interested study subjects. Pre-screening by this office will exclude patients who require more than minimal assistance to complete activities of daily living in order to select subjects who can safely participate in the full phenotyping protocol. All others will be contacted by the protocol team to review exclusion criteria. Eligible patients will be invited to Clinical Research Center for a screening visit.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Normal weight men and women over the age of 18 years with BMI greater than 18.5 and less than 25, who are reasonably healthy
Obese men and women over the age of 18 years with BMI greater than 30, who are reasonably healthy
Overweight men and women over the age of 18 years with BMI greater than 25 and less than 30, who are reasonably healthy
Phenotype (physical and behavioral traits) of overweight and obese people
The aim of this study is to extensively phenotype subjects with varying degrees of obesity, as well as those with rare adipose disorders such as multiple symmetric lipomatosis (Madelung s disease), Dercums disease (adiposis dolorosa) and lipedema; to assess their hormonal, metabolic, cognitive and behavioral traits.
Time frame: Two weeks
Started Mar 2007 (actual).
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) →