Personal profile


Iris Shai, RD, Ph.D., is a Professor of Nutrition and Epidemiology at BGU in nutrition, aging, and chronic diseases, an Adjunct Professor at Harvard University & Honorary Professor at Leipzig University, Germany. Shai is the Chair of the International Center of Health Innovation& Nutrition, Chair of the Cathedra of Epidemiology named by Dr. Herman Kessel, former BGU President's deputy on the advancement of women in academia, and a member of the Government Health Ministry Committee for Healthy Nutrition Regulations in Israel. Her focuses are obesity, diabetes, aging, cognition, epigenetics, microbiome, and cardiometabolic risk while performing long-term, large-scale comprehensive dietary randomized controlled trials (RCTs), in accordance with drug trial standards and long-term cohorts at Ben Gurion University (BGU) of Negev, Israel. Following her fellowship, awarded with Fulbright, in Harvard School of Public Health, where she focused on traditional and non-traditional biomarkers for CVD,  she led, with her international research team, the  2-year Dietary Intervention Randomized Controlled Trial (DIRECT) and 4-year follow-up (A Dietary Intervention- Randomized Controlled Trial (DIRECT) Study), comparing the effects of dietary strategies on cardiometabolic risk and plaque regression. In her next trial, CASCADE (The CArdiovasCulAr Diabetes & Ethanol (CASCADE) Trial), she addressed the 2-year effect of moderate alcohol in type 2 diabetes and her recent whole-body MRI trial, CENTRAL (Diet and Body Composition (CENTRAL)), focused on dynamic of human-specific fat depots and fuel metabolism across dietary strategies. Recently, she completed the DIRECT PLUS trial (Effects of Green-MED Diet Via the Gut-fat-brain Axis (DIRECT-PLUS)), which explores the effect of green Med diet and high- polyphenols on the gut-fat-brain axis. In this trial, new horizons were explored related to Autologous Fecal Microbiota Transplantation, brain atrophy attenuation, and epigenetics. The above-mentioned clinical trials serve in global nutritional guidelines in obesity, cardiology, diabetes, and fatty liver diseases. Currently, Shai directs the Follow Intervention Trials (FIT) project, which aims to identify predictors & and drivers determining personal health outcomes, such as age-related brain atrophy; utilizing an AI integration of four long-term, large-scale dietary clinical trials. The FIT will leverage a vast omics data bank from various human specimens, MRI scans, and health outcomes towards an approach of personalized medicine for overall health and specific clinical outcome. As part of Prof. Shai’s FIT project, data from the past four RCTs will be integrated for ~1000 participants with ~2000 person-years of intervention, with 5–16-year follow-up measures. MRI and clinical and biological samples will be measured, including biomarkers from blood, feces, urine, hair, nails, and saliva.

Shai teaches and counsels in Germany and the US in the areas of Novel Technologists in Dietary Clinical Trials and Effective Scientific Writing courses.

Key publications:  H-index = 59 (i10-index = 115); Total citations: 18,230

Research interests

  • Normal fasting plasma glucose levels and type 2 diabetes in young men.  N Engl J Med 2005
  • Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. N Engl J Med 2008
  • Adolescent BMI Trajectory and Risk of Diabetes versus Coronary Disease. N Engl J Med 2011
  • Four-year follow-up after two-year dietary interventions.  N Engl J Med 2012
  • Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults with Type 2 Diabetes: A 2-Year Randomized, Controlled Trial. Ann Intern Med2015
  • Effect of distinct lifestyle interventions on mobilization of fat storage pools: The CENTRAL MRI Randomized Controlled Trial. Circulation2018
  • The beneficial effects of Mediterranean diet over low-fat diet may be mediated by decreasing hepatic fat content. Journal of Hepatology 2019
  • Visceral and ectopic fat, atherosclerosis, and cardiometabolic disease: a position statement. Lancet Diabetes Endocrinol2019
  • Waist circumference as a vital sign in clinical practice: a Consensus Statement from the IAS and ICCR Working Group on Visceral Obesity. Nature Reviews Endocrinology 2020
  • Effects of Diet-Modulated Autologous Fecal Microbiota Transplantation on Weight Regain. Gastroenterology2020
  • DNA methylation signature in blood mirrors successful weight-loss during lifestyle interventions: the CENTRAL trial. Genome Med. 2020
  • The effect of green Mediterranean diet on intrahepatic fat; The DIRECT PLUS randomized controlled trial. Gut 2021
  • The gut microbiome modulates the protective association between a Mediterranean diet and cardiometabolic disease risk. Nature Med. 2021
  • The effects of the Green-Mediterranean diet on cardiometabolic health are linked to gut microbiome modifications: a randomized controlled trial. Genome Med. 2022
  • Proximal aortic stiffness might be regressed by healthy lifestyle modification, mainly by the Green-Mediterranean diet; the DIRECT-PLUS randomized controlled trial. JACC 2023

Expertise related to UN Sustainable Development Goals

In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This person’s work contributes towards the following SDG(s):

  • SDG 2 - Zero Hunger
  • SDG 3 - Good Health and Well-being
  • SDG 6 - Clean Water and Sanitation
  • SDG 12 - Responsible Consumption and Production
  • SDG 17 - Partnerships for the Goals

Education/Academic qualification

PhD, Ben-Gurion University of the Negev


Master, Hebrew University of Jerusalem


External positions

Adjunct Professor of Nutrition, Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University

Honorary Professor , Leipzig University

Member in the Government Health Ministry Committee for healthy Nutrition Regulations in Israel and the Israeli Cardiology Association committee for nutritional guidelines for preventive cardiology , Ministry of Health, Israel

My gallery


Dive into the research topics where Iris Shai is active. These topic labels come from the works of this person. Together they form a unique fingerprint.
  • 1 Similar Profiles

Collaborations and top research areas from the last five years

Recent external collaboration on country/territory level. Dive into details by clicking on the dots or