Dietary Treatment Study of Fat Synthesis and Risk of Cardiovascular Disease

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

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Overweight and Obesity
• Intervention / Treatment: Other: High sugar/meal feed; Other: High sugar/nibble; Other: High fat/meal feed; Other: High fat/nibble; Other: High sugar/ 3 meals a day; Other: High fat/ 3 meals a day

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.

• Study Type: Interventional
• Enrollment (Anticipated): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: OTHER
• Allocation: RANDOMIZED
• Interventional Model: FACTORIAL
• Masking: DOUBLE

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: High sugar/meal feed; Diet high in simple sugar fed as two large meals daily	Other: High sugar/meal feed; Weight-maintaining diet relatively high in sugar fed as two large meals daily; Other: High sugar/nibble; Weight-maintaining diet relatively high in sugar fed as 8 meals daily
EXPERIMENTAL: High sugar/nibble; Diet high in simple sugar fed as 8 small meals daily	Other: High sugar/meal feed; Weight-maintaining diet relatively high in sugar fed as two large meals daily; Other: High sugar/nibble; Weight-maintaining diet relatively high in sugar fed as 8 meals daily
EXPERIMENTAL: High fat/meal feed; Diet high in fat fed as two large meals daily	Other: High fat/meal feed; Weight-maintaining diet relatively high in fat fed as two large meals daily; Other: High fat/nibble; Weight-maintaining diet relatively high in fat fed as 8 small meals daily
EXPERIMENTAL: High fat/nibble; Diet high in fat fed as 8 small meals daily	Other: High fat/nibble; Weight-maintaining diet relatively high in fat fed as 8 small meals daily
EXPERIMENTAL: High sugar/3 meals a day; Diet high in simple sugar fed as 3 meals a day	Other: High sugar/ 3 meals a day; Weight-maintaining diet relatively high in sugar fed as 3 meals daily; Other: High fat/ 3 meals a day; Weight-maintaining diet relatively high in fat fed as 3 meals daily
EXPERIMENTAL: High fat/ 3 meals a day; Diet high in fat fed as 3 meals a day	Other: High sugar/ 3 meals a day; Weight-maintaining diet relatively high in sugar fed as 3 meals daily; Other: High fat/ 3 meals a day; Weight-maintaining diet relatively high in fat fed as 3 meals daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effect of meal composition on fractional de novo lipogenesis (fatty acid synthesis)	Differences between high carbohydrate and high fat diets on postprandial de novo lipogenesis De novo lipogenesis will be measured using stable (not radioactive) isotopes given intravenously and orally during feeding.	After 10-day dietary period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effect of meal frequency on fractional de novo lipogenesis (fatty acid synthesis)	Differences between consuming the same diet as eight small meals per day or two larger meals per day on postprandial de novo lipogenesis. Please see description of measurement of de novo lipogenesis under aim 1.	After 10-day dietary period

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Liver fat content	Effects of diet composition or meal frequency on fat stored in the liver. Liver fat content will be measured non-invasively using magnetic resonance spectroscopy.	After 10-day dietary period
Lipids and lipoproteins in the blood	Effects of diet composition or meal frequency on the types of fats in the bloodstream that might affect risk of heart disease. The types of fats in the bloodstream will be measured in blood samples collected while the participant is fasting and also during the stable isotope/feeding study of de novo lipogenesis.	After 10-day dietary intervention period

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Collaborators: Touro University, California
• Investigators: Principal Investigator: Jean-Marc Schwarz, PhD, Touro University, California

Study record dates

Study Major Dates

• Study Start: July 1, 2013
• Primary Completion (ANTICIPATED): December 1, 2022
• Study Completion (ANTICIPATED): December 1, 2022

Study Registration Dates

• First Submitted: February 26, 2014
• First Submitted That Met QC Criteria: February 27, 2014
• First Posted (ESTIMATE): March 3, 2014

Study Record Updates

• Last Update Posted (ACTUAL): May 19, 2022
• Last Update Submitted That Met QC Criteria: May 17, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Keywords: Lipid; Diet; Cardiovascular; Sugar
• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: Nibble99