John Gieng, PhD

Gieng profile picture

Associate Professor of Nutritional Sciences
General Education Program Coordinator
Department of Nutrition, Food Science & Packaging

Contacting Me


Licenses and Certificates

  • National Certified Phlebotomy Technician, CPT-1, since 2023

  • CPR-Basic Life Support, American Heart Association, since 2023

  • X-Ray Bone Densitometry (DXA) Technician, since 2018


Dr. John Gieng is a researcher who has studied nutrition in a variety of settings, including in the lab and in the community. He has used both in vitro and in vivo models, such as human and animal cell culture, rodents, and humans, in his work. His earlier research examined the effects of inflammation on the body's use of vitamin A, using mathematical modeling to better understand how nutrient deficiencies and disease can interact. Later, he focused on studying the role of gut microbiota in host health and diet-induced obesity, as well as the potential for teenagers to teach elementary school students about nutrition through a garden-based education program and how this can improve the teenagers' self-efficacy and ability to live a healthy lifestyle. At San José State University, Dr. Gieng combines his expertise in human metabolism, mammalian physiology, and applied nutrition education in his teaching and research.

Currently, Dr. Gieng's research centers on evaluating and improving health and performance through sustainable diets and behaviors. His research has three main areas of focus:

  1. Evaluating the nutritional quality of sustainable foods and their impact on health.
  2. Examining the impact of diet on health and related behaviors and programs using biotechnology.
  3. Investigating the relationships among nutrition, metabolism, body composition, health, and performance.

To learn more about Dr. Gieng's work, go to the Research and Publications pages.

Faculty Insights interview in fall 2021:


Twitter: @jgieng
LinkedIn: @johngieng
Instagram: @john.gieng