Clinical trial NCT02075710: Dietary Treatment Study of Fat Synthesis and Risk of Cardiovascular Disease
Official title: Lipogenesis, Lipoprotein Flux, and CVD Risk: Role of Meal Composition and Frequency
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Overweight and Obesity
Keywords: Diet
Sugar
Cardiovascular
Lipid
Lead sponsor: University of California, San Francisco
Sponsor class: OTHER
Collaborators: name: Touro University, California
First posted: 2014-03-03
Enrollment: 48
Sex: ALL
Minimum age (years): 20
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: OTHER

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Effect of meal composition on fractional de novo lipogenesis (fatty acid synthesis)
timeFrame: After 10-day dietary period
Secondary outcomes:
measure: Effect of meal frequency on fractional de novo lipogenesis (fatty acid synthesis)
timeFrame: After 10-day dietary period
Other outcomes:
measure: Liver fat content
timeFrame: After 10-day dietary period
measure: Lipids and lipoproteins in the blood
timeFrame: After 10-day dietary intervention period
Locations:
city: San Francisco
country: United States
facility: University of California, San Franciso, San Francisco General Hospital
state: California
Study officials:
affiliation: University of California, San Francisco
name: Kathleen Mulligan, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Touro University, California
name: Jean-Marc Schwarz, PhD
role: PRINCIPAL_INVESTIGATOR
References: