Dietary Fatty Acid Composition and Obesity-related Metabolic Abnormalities

Assessing the Effects of Two Diets Enriched in Either Saturated or Unsaturated Fatty Acids to Determine the Cellular and Molecular Mechanisms in Insulin Sensitivity

Individuals have a significant capacity to adapt to different environments by changing their core metabolic pathways. This adaptation is especially important in regards to diet. Epidemiological research over the last several decades have shown that diets high in saturated fats have a greater ability to cause insulin resistance and the 'metabolic syndrome' while diets low in saturated fats (or a so called 'Mediterranean Diet), reduces the risk for cardiovascular disease. In humans, experimental diets high in unsaturated fats, as compared to high carbohydrate or high saturated fat diets, result in increased insulin sensitivity and improved lipid profiles.

In this application, the investigators propose to systematically assess the effects of two diets enriched in either saturated or unsaturated fatty acids and determine the cellular and molecular mechanisms of the apparent increase in insulin sensitivity. The investigators hypothesize that individuals will 'adapt' to the different diets and the investigators will be able to generate predictive alterations in gene expression and metabolites that underlie the alterations in metabolism. In parallel, the investigators will test the ability of these different diets to affect the release of gastrointestinal hormones that may be critical to modulation of appetite.

Study Overview

• Status: Completed
• Conditions: Overweight/Obese Women
• Intervention / Treatment: Other: High Fat Diet

• Study Type: Interventional
• Enrollment (Anticipated): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • Michigan Clincal Research Unit

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Premenopausal females with BMI range of 25-32 kg/m2

Exclusion Criteria:

• Evidence of metabolic or cardiovascular disease, Fasting plasma glucose concentration > 125mg/dl, Abnormal EKG, Hyperlipidemia (plasma triglyceride concentration > 150mg/dl), Pregnancy, Hematocrit <34%

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: High Monounsaturated Fat Diet; Subjects will adhere to their specific diet for four weeks. The diet will be a weight-maintaining diet, and the target nutrient composition for diets will be 55% carbohydrate, 30% fat, 15% protein. For the monounsaturated fat treatment (M diet) approximately 10% of all lipids ingested will be saturated.	Other: High Fat Diet; Subjects will adhere to their specific diet for four weeks. For both diet treatments, the diet will be a weight-maintaining diet, and the target nutrient composition for diets will be 55% carbohydrate, 30% fat, 15% protein. For the monounsaturated fat treatment (M diet) approximately 10% of all lipids ingested will be saturated. For the saturated fat treatment (S diet) approximately 40% of all lipids ingested will be saturated.
Other: High Saturated Fat Diet; Subjects will adhere to their specific diet for four weeks. The diet will be a weight-maintaining diet, and the target nutrient composition for diets will be 55% carbohydrate, 30% fat, 15% protein. For the saturated fat treatment (S diet) approximately 40% of all lipids ingested will be saturated.	Other: High Fat Diet; Subjects will adhere to their specific diet for four weeks. For both diet treatments, the diet will be a weight-maintaining diet, and the target nutrient composition for diets will be 55% carbohydrate, 30% fat, 15% protein. For the monounsaturated fat treatment (M diet) approximately 10% of all lipids ingested will be saturated. For the saturated fat treatment (S diet) approximately 40% of all lipids ingested will be saturated.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin Sensitivity	A hyperinsulinemic-euglycemic clamp will be used to assess insulin sensitivity.	2-3 hours

Secondary Outcome Measures

Outcome Measure	Time Frame
Resting Metabolic Rate	20-30 min

Collaborators and Investigators

• Sponsor: University of Michigan
• Collaborators: Robert C. Atkins Foundation
• Investigators: Principal Investigator: Jeffrey F Horowitz, Ph.D., University of Michigan

Study record dates

Study Major Dates

• Study Start: August 1, 2007
• Primary Completion (Actual): December 12, 2010
• Study Completion (Actual): December 12, 2010

Study Registration Dates

• First Submitted: October 11, 2011
• First Submitted That Met QC Criteria: October 13, 2011
• First Posted (Estimate): October 14, 2011

Study Record Updates

• Last Update Posted (Actual): March 21, 2022
• Last Update Submitted That Met QC Criteria: March 18, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: insulin sensitivity; high fat diet treatment
• Additional Relevant MeSH Terms: Body Weight; Overweight
• Other Study ID Numbers: N009310