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Effect of Ultra Processed Versus Unprocessed Diets on Energy Intake

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03407053
Recruitment Status : Recruiting
First Posted : January 23, 2018
Last Update Posted : January 7, 2019
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) )

Brief Summary:


Eating too much processed food is believed to lead to obesity. But the effect of processed food on energy intake has not been carefully studied. Researchers want to study people s diets for 4 weeks and do specialized tests of the effects. Participants will get two diets. They will have the same calories and nutrients, but one diet will be unprocessed food and the other will be ultra-processed.


To better understand how processed and unprocessed foods affect daily food consumption and how the body handles blood sugar.


Healthy adults ages 18-50 who have stable weight and can exercise


Participants will not eat for 12 hours. Then they will be screened with:

  • Medical history
  • Physical exam
  • Heart and blood tests
  • Resting energy expenditure test (REE). A hood will collect air exhaled while lying down for 30-40 minutes.
  • Psychiatric questions
  • Questions about mood, eating, sleep, and socioeconomic status
  • 20-minute stationary biking

Female participants will have a urine pregnancy test.

Participants will stay in the clinic for 4 weeks. For 2 weeks they will get a processed diet. For the other 2 weeks they will get an unprocessed diet. Participants cannot use the study period to gain or lose weight.

Participants will have:

  • Meals and snacks provided
  • Daily exercise
  • Blood, urine, and saliva tests
  • To drink a special water and a very sweet liquid
  • REE
  • Scans and X-rays
  • To wear activity monitors and a device to measure blood sugar
  • Several 24-hour periods in a room that measures oxygen and carbon dioxide
  • Repeats of screening questions
  • Questions about hunger and meals
  • Sleep monitoring
  • Taste tests

Condition or disease
Healthy Healthy Volunteers

Detailed Description:
Overconsumption of foods that result from extensive industrial processing is believed to contribute to the development of obesity. Ultra-processed foods now represent most of the calories consumed in America and their contribution to overall diet has increased in parallel with the rise in the prevalence of obesity over the past several decades. While such correlations are suggestive, the effect of industrial processing per se, independent of dietary macronutrient composition, on ad libitum energy intake has not been carefully investigated. Therefore, we will conduct a feeding study in 20 adult men and women to investigate the differences in ad libitum energy intake resulting from consuming two test diets for a pair of 2-week periods in a randomized, crossover design during a single 4-week period. The test diets presented to participants will be matched for calories, macronutrient composition, sugar, fiber, and sodium, but one diet will be composed of ultra-processed foods whereas the other diet will be unprocessed foods.

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Study Type : Observational
Estimated Enrollment : 200 participants
Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Effect of Ultra Processed Versus Unprocessed Diets on Energy Intake
Actual Study Start Date : March 1, 2018
Estimated Primary Completion Date : February 29, 2020
Estimated Study Completion Date : December 31, 2020

Adult men and women

Primary Outcome Measures :
  1. To determine differences in ad libitum energy intake (kcals) during 2 weeks of eating an ultra-processed diet as compared to 2 weeks of an unprocessed diet matched for presented calories, macronutrient composition, sugar, fiber, and sodium. [ Time Frame: Ongoing ]

Secondary Outcome Measures :
  1. Changes in oral glucose tolerance [ Time Frame: Ongoing ]
  2. Differences in inflammatory markers; [ Time Frame: Ongoing ]
  3. Changes in body weight and body composition [ Time Frame: Ongoing ]
  4. Changes in energy expenditure and substrate metabolism [ Time Frame: Ongoing ]
  5. Changes in hepatic triglyceride. [ Time Frame: Ongoing ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
20 adult men and women

    1. Adults age 18-50 years, male and female
    2. Weight stable (< +/- 5 % over past 6 months)

    4. Body mass index (BMI) greater than or equal to 18 kg/m^2

    5. Willing to cease their habitual caffeine intake during the study, beginning one week prior to inpatient admission

    6. Written informed consent

    7. Willing to eat the food provided in the study

    8. Able to complete daily bouts of stationary cycling at a moderate rate and intensity with a HR equal to or greater than 0.3x(220-age-HR(rest))+HR(rest) but not exceeding 0.4x(220-age-HR(rest))+HR(rest) and no signs of arrhythmia


  1. Evidence of metabolic or cardiovascular disease, or disease that may influence metabolism (e.g. cancer, diabetes, thyroid disease)
  2. 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)
  3. Hematocrit < 34% (women only)
  4. Hematocrit < 40% (men only)
  5. Pregnancy, lactation (women only)
  6. Participating in a regular exercise program (> 2h/week of vigorous activity)
  7. Caffeine consumption > 300 mg/day
  8. Regular use of alcohol (> 2 drinks per day), tobacco (smoking or chewing) amphetamines, cocaine, heroin, or marijuana over past 6 months
  9. Eating disorders or psychological conditions, such as (but not limited to) claustrophobia, clinical depression, bi-polar disorders, that would be incompatible with safe and successful participation in this study, as determined by investigators.

    --Past or present history of claustrophobia since part of the protocol will involve being confined to a small room for whole-body indirect calorimetry and being in an MRI scanner for liver fat measures

  10. Implants, devices, or foreign objects implanted in the body that interfere with the Magnetic Resonance procedures
  11. Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, food allergies)
  12. Volunteers unwilling or unable to give informed consent
  13. Non-English speakers due to unavailability of required questionnaires in other languages.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03407053

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Contact: Irene T Rozga, R.N. (301) 496-1069

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United States, Maryland
National Institutes of Health Clinical Center Recruiting
Bethesda, Maryland, United States, 20892
Contact: For more information at the NIH Clinical Center contact Office of Patient Recruitment (OPR)    800-411-1222 ext TTY8664111010   
Sponsors and Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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Principal Investigator: Kevin Hall, Ph.D. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Additional Information:
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Responsible Party: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Identifier: NCT03407053     History of Changes
Other Study ID Numbers: 180044
First Posted: January 23, 2018    Key Record Dates
Last Update Posted: January 7, 2019
Last Verified: December 28, 2018

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) ):
Food Intake
Body Composition
Body Weight Regulation