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Protocol Details

Dinner Time for Obesity and Prediabetes (DTOP)

This study is currently recruiting participants.

Summary | Eligibility | Citations | Contacts




Sponsoring Institute

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Participants currently recruited/enrolled
Gender: Male & Female
Min Age: 18 Years
Max Age: 50 Years

Referral Letter Required


Population Exclusion(s)



Food Intake;
Fat Oxidation;
Dim Light Melatonin Onset (Dlmo);
Metabolic Dysfunction

Recruitment Keyword(s)



Type 2 Diabetes (T2dm)

Investigational Drug(s)


Investigational Device(s)



Other: Early Dinner (ED)
Other: Late Dinner (LD)

Supporting Site

National Institute of Diabetes and Digestive and Kidney Diseases


Studies suggest that eating late at night is linked with obesity; however, these studies do not account for differences in people s internal clocks. Researchers want to learn more.


To study how eating at different times, relative to a person s internal clock, affects metabolism.


People aged 18 to 50 years. Two groups are needed: people who are obese and have prediabetes, and people who have a normal weight and are healthy.


Participants will have one overnight stay at Johns Hopkins University (JHU) and two 2-night stays at the National Institutes of Health (NIH).

One week before each overnight visit, participants will wear a device like a wristwatch to monitor their activities. They will keep diaries of their food and sleep. They will wear a sensor on their skin to monitor their blood sugar levels. Before the NIH visits, they will be asked to sleep at certain times.

At JHU, participants will swallow a pill-sized thermometer. They will sit still in dim lighting for up to 10 hours; saliva will be collected every 30 minutes. They will lie under a plastic dome to measure how much oxygen they use as they breathe.

At NIH, participants will stay in a special room that monitors the oxygen they inhale and the carbon dioxide they exhale. Lights will be turned on and off and meals will be delivered on a set schedule. They will have a thin tube placed in a vein in the arm for drawing blood.

The NIH stay will be repeated after 3 to 4 weeks. The sleep and meal schedules will be different at each visit.

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Participants must meet all of the inclusion criteria to participate in this study.

-Normal-weight healthy (NWH) cohort:

--Healthy male and female adults, age 18-50

--BMI 18-24.9 kg/m2

-Obesity-Prediabetes (OPD) cohort:

--Male and female adults, age 18-50

--BMI >=30 kg/m2

--Prediabetes defined by hemoglobin A1c 5.7-6.4% or fasting glucose from 100 to 125 mg/dL or 2-hour glucose from 140 to 199 mg/dL after 75-gram oral glucose tolerance test

-All participants must be able to understand study procedures, to comply with them for the entire length of the study and be fully mobile.


All candidates meeting any of the exclusion criteria at baseline will be excluded from study participation.

-Sleep disorder including insomnia, untreated moderate-severe sleep apnea, restless leg syndrome, or narcolepsy

-Night shift work

-Extreme delayed sleep phase defined as self-reported routine bedtime later than 1:00AM or having mid-sleep on free days later than 5:00AM on the Munich Chronotype Questionnaire (MCTQ) or DLMO later than 24:00

-Gastroesophageal reflux disease that affects ability to tolerate a dinner close to bedtime

-Active smoking (may interfere with metabolism and CRU activities)

-Current drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements.

-Diabetes (type 1 or 2) or on any diabetes medications besides metformin

-Evidence of metabolic or cardiovascular disease, or disease that may influence metabolism (e.g. cancer, thyroid disease)

-HbA1c point of care >=5.7% for NWH cohort; HbA1c point of care >=6.5% for OP cohort

-Point-of-care hemoglobin < 10 g/dL

-Self-reported kidney disease

-Any known history of an inherited metabolic disorder

-Pregnant or lactating female (pregnancy test will be required prior to metabolic visits)

-Peri-menopausal or post-menopausal female as determined by follicle stimulating hormone of > 30 mIU/mL or fewer than 3 menstrual periods in 6 months

-Professional or collegiate athlete

-Travel across >1 time zone within a 3-month period before and during the protocol

-Weight less than 40 kg or more than 180 kg

-Gastrointestinal disorders that can lead to obstruction of the digestive tract (i.e. diverticular disease, history of bowel obstruction, inflammatory bowel disease, motility disorder)

-History of any surgical procedures in the gastrointestinal tract.

-Swallowing disorders

-Taking any prescription medication or other drug that may influence metabolism (e.g. diet/weight-loss medication, asthma medication, blood pressure medication, psychiatric medications, corticosteroids, or other medications at the discretion of the PI and/or study team)

-Chronic use of sedative hypnotics, anxiolytics, opiates

-Use of medications that can affect circadian rhythm (beta blockers, melatonin)

-Presence of a cardiac pacemaker or other implanted electro-medical devices

-Those who have to undergo strong electromagnetic field during the period of use of the ingestible thermosensor (i.e. MRI)

-Weight loss or gain of >= 5% of total body weight over the preceding 3 months

-Currently participating in a weight loss program

-Prior bariatric surgery

-Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, food allergies)

-History of significant intravenous access issues

-Non-English speaking individuals: The complexity of the instructions for various components of the study would make the study procedures difficult to follow in the setting of a language barrier.

-Other conditions or situations at the discretion of the PI

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Not Provided

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Principal Investigator

Referral Contact

For more information:

Stephanie T. Chung, M.D.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
NIHBC 10 - CRC BG RM 5-5940
(240) 479-8137

Lilian S. Mabundo
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
National Institutes of Health
Building 10
Room 5-5750
10 Center Drive
Bethesda, Maryland 20892
(240) 383-9379

Office of Patient Recruitment
National Institutes of Health Clinical Center (CC)
Building 61, 10 Cloister Court
Bethesda, Maryland 20892
Toll Free: 1-800-411-1222
Local Phone: 301-451-4383
TTY: TTY Users Dial 7-1-1

Clinical Trials Number:


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