A Phase 2 interventional study of Weight Loss and Overfeeding in Obesity, Diet Therapy and Weight Loss, sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Completed at 1 site in United States. Open to participants aged 18 Years to 60 Years. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) · Phase 2, Interventional, and Treatment
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 36th largest by enrollment of the 66 interventional ones that give a count, is one of 3 that started in 2008, is one of 20 in phase 2, and was the 67th 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 60 Years · all sexes · no healthy volunteers.
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. 3 started in 2008.
This study's enrollment of 83 is above the median of 67 across 9,006 interventional 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 investigate how to better predict why some individuals gain or lose weight more easily than others. It will examine whether the increase in the amount of energy a body burns in 24 hours with overeating or the decrease over 24 hours with fasting can help determine how easily someone gains or loses weight.
Healthy people between 18 and 60 years of age who have a body mass index (BMI) between 18.5 kg/m(2) and 24 kg/m(2) (for overfeeding study) or a BMI greater than 27 kg/m(2) with a body weight less than 350 pounds (weight loss study) may be eligible for this study. The study requires a 10-week admission to the NIH Clinical Center (2-week baseline, 6-week overfeeding/weight loss, 2-week post-weight change).
Participants undergo the following tests and procedures during the hospital admission:
Followup procedures after the inpatient stay:
For obese individuals, losing weight and keeping it off are extremely difficult, whereas some other individuals are thin and report trouble gaining weight. In most weight loss and overfeeding studies there is a large variation in the amount of weight lost or gained, and it is not clear whether an individual s response to an intervention can be predicted. Measurement of the amount of energy an individual uses over 24 hours (24 hour energy expenditure or 24-EE) and the response of 24-EE to overfeeding and fasting may help predict which individuals will have the greatest changes in weight with changes in energy balance. In previous work, 24-EE responses to overfeeding and fasting were related such that individuals with the greatest increase in 24-EE upon overfeeding tended to have the smallest decrease in 24-EE upon fasting ( spendthrift phenotype) and those individuals with less increase in 24-EE during overfeeding had a greater decrease in 24-EE with fasting ( thrifty phenotype). Those with the spendthrift phenotype who had a greater increase in 24-EE in response to overfeeding gained less weight over time. Furthermore, studies have shown that diets with very low protein content may magnify the variability in response to overfeeding.
The aim of this study is to determine if a phenotype defined by 24-EE responses to overfeeding and underfeeding is related to weight loss or gain in 4 different under- and overfeeding settings: an inpatient weight loss group for obese individuals who will be administered one of two diets based on a 50% reduction of their daily energy needs for six weeks (standard reduction diet or calorie reduced diet that is still high in protein; 6 week weight reduction, 10 week stay, n=20/standard reduction diet group and n=10/relative high protein diet), and two overfeeding groups for lean, weight gain resistant individuals: a low-protein overfeeding group at 150% of daily energy needs for 6 weeks overfeeding (6% protein, 64% carbohydrate, 30% fat; 10 week stay, n=10), and a normal protein overfeeding group at 150% of daily energy needs for 6 weeks overfeeding (20% protein, 50% carbohydrate, 30% fat; 10 week stay, n=10). We will also examine additional metabolic and behavioral measurements to determine how they relate to weight change and changes in 24-EE. These include sympathetic nervous system activity, behavior, adipose and muscle tissue energy content, and abdominal adipocyte size. The study will evaluate the relationship between the percent increase in 24-EE in response to overfeeding/underfeeding and the amount of weight change over time in each subject. These findings may provide important information for predicting and adapting specific individualized interventions for obesity.
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.
EXCLUSION CRITERIA:
Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators. Additionally, potential subjects might be excluded if they demonstrate a style of interpersonal relationships that would inhibit successful completion of the study.
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.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
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.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
an inpatient overfeeding arm in which obesity resistant individuals are prescribed a 150% increase in a weight maintenance calorie diet for 6 weeks which (by random assignment) is either low in protein (6%) content. Overfeeding or Overfeeding Low Pro or with normal (20%) protein content
Behavioral: Overfeeding · Behavioral: Overfeeding Low Pro
a weight loss arm in which obese individuals are placed on a 50% decrease from a weight maintenance calorie diet for 6 weeks which (by random assignment) is either a standard 50% decrease in energy intake with all macronutrients held at the same percentage (20% protein, 50% carbohydrate, 30% fat) or a 50% decrease in energy intake with the same absolute protein content (in grams) as the weight maintaining diet while on our clinical research unit then followed as outpatients monthly for 10 months
Behavioral: Weight Loss
liquid diet at 50% of weight maintaining intake
Overfeeding at 150% of weight maintaining intake
Overfeeding 150% of normal intake at \<5% protein
The primary goal of the current study is to determine if changes in energy expenditure in response to acute over- and underfeeding are related to variation in changes in weight and body energy stores with longer-term over- and underfeeding.
Changes in energy expenditure, weight, and body energy stores measured via physical examinations, laboratory studies, questionnaires, body composition assessments, oral glucose tolerance tests, metabolic chamber studies, and free-living energy use studies
Time frame: Ongoing
Determine if hormones, responses to behavioral testing, adipocyte size, body composition, core temperature, spontaneous activity, and food absorption/excretion are related to changes in EE with over/under-feeding and variation in weight change.
Changes in hormones, behavior, adipocyte size, body composition, core temperature, spontaneous activity, food absorption/excretion, changes in EE, and weight measured via physical examinations, laboratory studies, questionnaires, body composition assessments, oral glucose tolerance tests, meal tests, activity monitors, metabolic chamber studies, free-living energy use studies, and fat and muscle biopsies
Time frame: Ongoing
Plan to share: Undecided
Ran from Sep 2008 to primary completion in Dec 2018, 123 months.
Of 132 non-industry phase 2 interventional studies under Obesity, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 57. This study's 123 months is above that.
Counting every sponsor, half of 308 studies reached it within 16 months; a quarter within 10 and three quarters within 35.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) →