for people ages 20-65 (full criteria)
Healthy Volunteers
healthy people welcome
at San Francisco, California
study started
completion around
Principal Investigator
by Kathleen Mulligan
Headshot of Kathleen Mulligan
Kathleen Mulligan



The purpose of this study is to find out how the amount of fat or sugar in a person's diet, or the number of meals eaten each day, affect the amount of fat that people's bodies make, the types of fats in the bloodstream, and how much fat is stored in the liver. The study is funded by the National Institutes of Health.

Official Title

Lipogenesis, Lipoprotein Flux, and CVD Risk: Role of Meal Composition and Frequency


The study consists of two 10-day feeding periods that are separated by approximately two weeks. During each feeding period all food and beverages to be consumed will be provided by the study.

In Study 1, participants will be randomly assigned to receive one of two diets. Both diets are designed to maintain weight at a constant level. The diets are balanced nutritionally and have the same amount of protein. One diet has higher amounts of sugar, while the other has higher amounts of fat. For one 10-day period, the diet will be fed as two large meals ('meal-feeding'). For the other 10-day period, the identical diet will be fed as 8 small meals ('nibbling'). Half of the participants will meal-feed first, while the other half will 'nibble' first. The order of nibbling or meal feeding will be determined randomly.

In Study 2, the number of meals eaten per day will remain fixed at three (no nibbling or meal feeding). Participants will receive both the diet higher in sugar and the diet higher in fat. However, they will be randomly assigned to start one followed by the other for each 10-day feeding period.

At the end of each 10-day feeding period, participants will spend two nights in a research ward (Clinical Research Center) to undergo testing.


Overweight and Obesity, Diet, Sugar, Cardiovascular, Lipid, Overweight, High sugar/meal feed, High sugar/nibble, High fat/meal feed, High fat/nibble, High sugar/ 3 meals a day, High fat/ 3 meals a day


You can join if…

Open to people ages 20-65

  • overweight or obese men and women
  • ages 20-65 years

You CAN'T join if...

  • pregnancy or lactation within the past six months
  • type 1 or 2 diabetes mellitus]
  • AST and ALT above upper limit of normal (ULN)
  • fasting triglyceride or total cholesterol levels >ULN
  • Hgb below the lower of limit of normal
  • positive HIV antibody test or hepatitis serologies
  • use of any antidiabetic medications or lipid-lowering drugs
  • history of surgery for obesity
  • change in body weight >5% within preceding 6 months (self report)
  • claustrophobia, presence of metal implants
  • weight over 350 lbs


  • University of California, San Franciso, San Francisco General Hospital
    San Francisco California 94110 United States

Lead Scientist at UCSF

  • Kathleen Mulligan
    I study the nutritional and metabolic effects of chronic conditions including HIV infection and its therapies, obesity, fatty liver disease, and type 2 diabetes, with a focus on body composition, glucose and lipid metabolism, endocrine function, and bone metabolism; and a strong emphasis on treatments and mechanisms.


in progress, not accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Expecting 48 study participants
Last Updated