Effect of Ultra Processed Versus Unprocessed Diets on Energy Intake
Condition: Healthy Diet
Study type: Interventional

Summary: 
      Background:

      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.

      Objective:

      To better understand how processed and unprocessed foods affect daily food consumption and
      how the body handles blood sugar.

      Eligibility:

      Healthy adults ages 18-50 who have stable weight and can exercise

      Design:

      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
    

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 feeding studies in adult men and women to
      investigate the differences in ad libitum energy intake resulting from consuming 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.
    

Intervention name(s): Ultra-processed diet; Unprocessed diet
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Consuming ultra-processed diet over a 2-week period; Consuming unprocessed diet over a 2-week period
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Calories; Food Intake; Glucose; Body Composition; Body Weight Regulation