About HAT

Welcome, and thank you for your interest in HAT!

The trial

  • HAT stands for Habitual diet and Avocado Trial.
  • HAT is a research project aimed to answer the question whether eating an avocado every day impacts energy balance and metabolism. There are four Universities participating in this trial: Tufts University, Loma Linda University, Pennsylvania State University, and UCLA.
  • The trial is completed over the course of SIX months inside and outside of the laboratory. We are looking for men and women at least 25 years of age to participate and contribute to our project.

To be eligible you must meet the following criteria:

  • BMI of at least 25 for women or at least 27 for men
  • Willing to undergo two MRI scans of your abdomen
  • Not pregnant, lactating, or have an intention of pregnancy during the trial
  • No significant body weight change in the last year

Lab Visits

  • You will be asked to visit the lab eight times over the course of the trial (up to 90 minutes per visit) to complete questionairs, vitals, and blood draws
  • You will complete two MRI visits, each lasting less than one hour
  • You will complete four telephone interviews throughout the trial (approximately 40 minutes)
  • Half of the participants will be required to pick up trial items every two weeks (10 minutes)
  • Some participants may be asked to complete computer tests, blood pressure tests, and/or provide fecal and urine samples


You will receive a stipend and gifts throughout the trial and at trial completion

Interested in participating?

Please consider the contributions we are asking you to make in this trial:
  • Every two weeks, you may be required to pick up trial items
  • You must be available to participate in ALL eight clinic visits and four telephone interviews throughout the course of the six month trial
  • You will be required to undergo two MRI's
  • You may be required to limit your intake of avocado to two avocados or less a month
  • You may be required to eat an avocado every day for six months
  • You will be required to follow trial protocol, even while traveling and celebrating holidays and events

To sign up for a 15 minute phone screening to see if you qualify, please contact us at:

Penn State - Hershey

500 University Drive
Hershey, PA 17033


900 Weyburn Place
Los Angeles, CA 90024

Penn State - University Park

Clinical Research Center
211 Noll Lab, Elmore Research Wing
University Park, PA 16802

Loma Linda University

Parkland Building
10970 Parkland Avenue
Loma Linda, CA 92350