functional nutrition

Sibo Doctor Approved
Alyssa Simpson RD, CDE, CLT
Alyssa Simpson

(602) 422-9800

Sibo Doctor Approved
certified gastrointestinal nutritionist
Sibo Doctor Approved
certified gastrointestinal nutritionist

I’m Alyssa Simpson, a Registered Dietitian specializing in gut and digestive issues.

BUT, I’m also an Integrative and Functional Nutrition Therapist. I’m dedicated to resolving the issues causing the symptoms that are bothering you, not just giving you a temporary fix. I use a combination of tools to address the root cause of your gut problems so you can finally feel better.

When you work with me, you reap the benefits of my advanced training in medical nutrition therapy, integrative and functional nutrition, specialty testing, personalized meal planning, and dietary supplementation.

My philosophy is simple. Your body craves balance, and nutritious food provides the fuel to support this desirable state. But factors in your environment and even your frame of mind can offset this delicate balance. The result is one miserable digestive system.

If you’re not familiar with Functional Medicine, it showcases nutrition as the cornerstone of TRUE WELLNESS. And the foundation of your well-being depends on your gut health. 

If you’ve seen a doctor for your digestive problems, you know our current healthcare system is based on merely identifying illness and treating symptoms. But functional and integrative medicine methods show us we can truly heal by discovering and correcting our unique imbalances. So often, the root cause of illness lies in the gut, so this is where I start. 

I’ll work with you to get the solutions you’re looking for and help you reset your system. And since so many processes in your body hinge on digestive health, you’ll not only get relief from symptoms; you’ll experience the advantages good gut health has on your total well-being!

Using this specialized approach, I’ve been able to restore hope and health to thousands of patients. These are people who tried doctor after doctor but were left with no answers or, even worse, were told there was nothing wrong with them. 

At every virtual appointment, we’ll dig into strategies and use proven methods to correct your unique imbalances so you can truly heal.

I love seeing people finally feel relief and begin to thrive once they start working with me. I enjoy the challenge of developing sustainable nutrition plans that get real results for people living with digestive problems because I’m one of them!

About a year after starting my private practice, I developed acid reflux. Since my specialty is helping patients with digestive conditions, it was exciting to use my skills to manage my own. But what was even more eye-opening was the opportunity to see what it’s like to be in my patient’s shoes. I was able to see firsthand how stress was triggering my reflux. I also witnessed how changing my diet and lifestyle to correct imbalances transformed my health.

I’m now symptom-free and feeling better than ever. When I’m not busy with patients, you can find me spending time outdoors in the Gilbert, AZ area. An athlete at heart, I love the feel-good benefits of hiking, spoiling my dog with long walks, group exercise classes, weight lifting, and running. My young nieces also keep me on my toes!

Two very special people helped shape my interest in nutrition. The first is my mom, who I credit with teaching me to love healthy food as a child. The second is my high school cross-country and track coach, who taught me the importance of eating to fuel my performance. 

I’m so grateful I get to do what I’m most passionate about – working to get people with challenging digestive issues back on track! I know you’ve tried lots of things to soothe your gut symptoms before landing on my website. Get in touch, and I’ll show you how to get control of your gut health. I can’t wait to help you get better!

Education And Experience

  • B.S. in Dietetics, Arizona State University 2003
  • Completion of supervised practice program, Patton State Hospital 2004
  • Dietetic Registration Exam 2004
  • Nutrition Coach, Lifetime Fitness 2004-2005
  • Nutrition Coordinator, Adelante Healthcare 2005-2010
  • Passed Certified Diabetes Educator Exam 2009
  • Diabetes Health Coach, Nurtur 2010-2012
  • LEAP Therapist certification 2011
  • Private Practice 2012-present
  • Partnered with Arizona Digestive Health since 2013
  • Nutritionist at Fairmont Scottsdale Princess Resort Well & Being Spa, under Chief Medical Officer Tieraona Low Dog MD, Director of Fellowship of the Arizona Center for Integrative Medicine at the University of Arizona, founded by Dr. Andrew Weil  2013-2015
  • Integrative and Functional Medical Nutrition Therapy (IFMNT) Level II Certificate of Training Course 2014
  • Completed Integrative and Functional Medical Nutrition Therapy (IFMNT) Level III Certificate of Training Course 2015
  • Trained on the use of the Low FODMAP Diet by Monash University May 2023
  • Completed Certified Gastrointestinal Nutritionist Certification June 2023
  • Completed SIBO Mastery Program by Nirala Jacobi October 2023


  • Academy of Nutrition and Dietetics (AND)
  • Nutrition Entrepreneurs (NE)
  • Dietitians in Integrative and Functional Medicine (DIFM)
  • Central District of the Arizona Academy of Nutrition and Dietetics (C-AZAND)
Alyssa Simpson RD, CDE, CLT
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