Liver Disease

Jonathan Stine, MD, MSc, FACP, is an associate professor of medicine and public health science at Penn State in State College, Pennsylvania.

As an internationally recognized liver expert with a research and clinical focus on metabolic dysfunction–associated steatotic liver disease (MASLD) and exercise, he has authored more than 100 peer-reviewed papers, including multinational consensus guidelines.

Dr. Stine is the recipient of multiple research grants and awards from the American Association for the Study of Liver Diseases and the American Cancer Society, and has maintained continuous funding from the National Institutes of Health since 2018.

Stine is the MASLD consultant to the American College of Sports Medicine’s “Exercise is Medicine” initiative, and recently co-chaired the International Roundtable on MASLD and Physical Activity for ACSM. He serves as the Fatty Liver Program director as well as the Liver Center Research director for Penn State.

Justin Laube, MD, is a board-certified integrative and internal medicine physician, a teacher, and a consultant with extensive expertise in integrative health, medical education, and trauma healing.

He graduated with a bachelor's in biology from the University of Wisconsin and a medical degree from the University of Minnesota Medical School. During medical school, he completed a graduate certificate in integrative therapies and healing practices through the Earl E. Bakken Center for Spirituality & Healing. He completed his three-year residency training in internal medicine at the University of California in Los Angeles on the primary care track and a two-year fellowship in integrative East-West primary care at the UCLA Health Center for East-West Medicine.

He is currently taking a multiyear personal and professional sabbatical to explore the relationship between childhood trauma, disease, and the processes of healing. He is developing a clinical practice for patients with complex trauma, as well as for others going through significant life transitions. He is working on a book distilling the insights from his sabbatical, teaching, and leading retreats on trauma, integrative health, mindfulness, and well-being for health professionals, students, and the community.

Previously, Dr. Laube was an assistant clinical professor at the UCLA Health Center for East-West Medicine and the David Geffen School of Medicine at UCLA, where he provided primary care and integrative East-West medical consultations. As part of the faculty, he completed a medical education fellowship and received a certificate in innovation in curriculum design and evaluation. He was the fellowship director at the Center for East-West Medicine and led courses for physician fellows, residents, and medical students.

Allison Buttarazzi, MD, is board-certified in internal medicine and lifestyle medicine, and is a certified health and well-being coach. In her primary care practice, Dr. Buttarazzi focuses on lifestyle medicine to help her patients improve their health and longevity, and her passion is helping patients prevent and reverse chronic diseases (like heart disease, high blood pressure, and diabetes) by improving their lifestyle habits.

She is a graduate of Tufts University School of Medicine and completed a residency at Maine Medical Center. Diagnosed with celiac disease during medical school, she realized the power of improving one's health through diet and lifestyle habits, which she later incorporated into her practice.

Lynn Grieger is a registered dietitian-nutritionist, certified diabetes care and education specialist, certified personal trainer, and certified health and wellness coach. She completed requirements to become a registered dietitian at Valparaiso University in 1987 and completed a dietetic internship at Ingalls Memorial Hospital in Harvey, Illinois, in 1988. 

Lynn brings her expertise in nutrition, exercise, and behavior change to her work in helping people reach their individual health and fitness goals. In addition to writing for Everyday Health, she has also written for websites and publications like Food and Health Communications, Today's Dietitian, iVillage.com, and Rodale Press. She has a passion for healthy, nutrient-dense, great-tasting food and for being outdoors as much as possible — she can often be found running or hiking, and has completed a marathon in every state.

Waseem Ahmed, MD, is an assistant professor of medicine in the Karsh Division of Gastroenterology and Hepatology at Cedars-Sinai Medical Center in Los Angeles and serves as Director, Advanced Inflammatory Bowel Disease Fellowship and Education within the F. Widjaja Inflammatory Bowel Disease Institute.

He received his undergraduate degree from the University of Michigan and attended medical school at Indiana University. He then completed an internal medicine residency at New York University, followed by a fellowship in gastroenterology and hepatology at Indiana University, and an advanced fellowship in inflammatory bowel disease at the Jill Roberts Center for Inflammatory Bowel Disease at New York-Presbyterian Hospital/Weill Cornell Medicine. Prior to his current role, Dr. Ahmed served as an assistant professor of medicine within the Crohn’s and Colitis Center at the University of Colorado from 2021-2024.

Dr. Ahmed is passionate about providing innovative, comprehensive, and compassionate care for all patients with inflammatory bowel disease (IBD). His research interests include IBD medical education for patients, providers, and trainees; clinical trials; acute severe ulcerative colitis; and the use of combined advanced targeted therapy in high-risk IBD.

He enjoys spending time with his wife and dog, is an avid follower of professional tennis, and enjoys fine dining.

Ira Daniel Breite, MD, is a board-certified internist and gastroenterologist. He is an associate professor at the Icahn School of Medicine at Mount Sinai, where he also sees patients and helps run an ambulatory surgery center.

Dr. Breite divides his time between technical procedures, reading about new topics, and helping patients with some of their most intimate problems. He finds the deepest fulfillment in the long-term relationships he develops and is thrilled when a patient with irritable bowel syndrome or inflammatory bowel disease improves on the regimen he worked with them to create.

Breite went to Albert Einstein College of Medicine for medical school, followed by a residency at NYU and Bellevue Hospital and a gastroenterology fellowship at Memorial Sloan Kettering Cancer Center. Working in city hospitals helped him become resourceful and taught him how to interact with people from different backgrounds.

Jennifer K. Frediani, PhD, RD, ACSM-CES, is a nutrition scientist, exercise physiologist, and registered dietitian with over two decades of experience in clinical research, education, and lifestyle intervention. She's an assistant professor, research track, at the Nell Hodgson Woodruff School of Nursing at Emory University, adjunct faculty in the nutrition and health sciences program at the Rollins School of Public Health, and a member of the Winship Cancer Institute.

Dr. Frediani earned her PhD in nutrition science from Emory University, and a master’s in exercise science and a bachelor’s in nutrition and dietetics from Georgia State University. Her doctoral research focused on body composition and dietary assessment among tuberculosis patients in the Republic of Georgia, and her postdoctoral work explored nutritional influences on pediatric liver disease.

She has published widely in journals such as Nature Scientific Reports, The New England Journal of Medicine, Clinical Nutrition, and Progress in Cardiovascular Diseases.

At Emory, she directs adult clinical studies for the NIH RADx initiative, overseeing trials on novel diagnostics for infectious diseases. She also leads the development of Emory’s fully online master of science in clinical nutrition program, designed to prepare future registered dietitian nutritionists through integrated coursework and supervised experiential learning.

Her research focuses on weight-neutral lifestyle interventions to improve cardiometabolic outcomes, with a special emphasis on dietary assessment, physical activity, and metabolomics.

Frediani’s teaching philosophy centers on creating inclusive, student-driven learning environments that foster critical thinking and professional growth. She is passionate about reducing weight stigma in clinical care and promoting sustainable, individualized approaches to food and movement.

Outside of work, Frediani is an avid runner and food enthusiast who travels the world to explore culinary traditions and cultural foodways. She believes that everyone deserves to enjoy food that nourishes both body and soul — without shame or restriction.

Natalia Johnsen, MD, practices internal medicine and lifestyle medicine. She works as an internist for the Vancouver Clinic in Vancouver, Washington.

Johnsen trained and worked as ob-gyn in Russia before coming to the United States in 2000. Subsequently, she interned in internal medicine at the University of Nevada and completed her residency at a Stanford-affiliated program in Santa Clara, California. After that she worked as a general internist for two years before to switching to full-time hospital work.

Johnsen has always been fascinated by the effects that lifestyle can have on physical and mental health, and she fell in love with the concept of lifestyle medicine as a specialty after seeing patients struggle with issues that could have been prevented had they known more about a healthy lifestyle. To make an impact on her patients through lifestyle interventions, she launched her own lifestyle medicine clinic, Vivalso Health and Longevity.

Marina Serper, MD, MS, is a transplant hepatologist, an associate professor of medicine in gastroenterology at the University of Pennsylvania Perelman School of Medicine, and staff physician at the Corporal Michael J. Crescenz VA Medical Center in Philadelphia.

Dr. Serper's research focuses on investigating barriers to access and high quality care for patients with liver disease; designing behavioral and health-system interventions utilizing health technology to improve care delivery and outcomes in chronic liver disease and liver transplantation; and evaluating how health literacy, medication understanding, and cognitive function affect medication adherence, self-care and health outcomes.

Michelle Seguin, MD, is a board-certified family medicine, lifestyle medicine, and certified functional medicine physician (IFMCP). She is a practicing physician at Root Functional Medicine, a leading telemedicine practice specializing in personalized, root-cause care.

Yuying Luo, MD, is an assistant professor of medicine at Mount Sinai West and Morningside in New York City. She aims to deliver evidence-based, patient-centered, and holistic care for her patients.

Her clinical and research focus includes patients with disorders of gut-brain interaction such as irritable bowel syndrome and functional dyspepsia; patients with lower gastrointestinal motility (constipation) disorders and defecatory and anorectal disorders (such as dyssynergic defecation); and women’s gastrointestinal health.

She graduated from Harvard with a bachelor's degree in molecular and cellular biology and received her MD from the NYU Grossman School of Medicine. She completed her residency in internal medicine at the Icahn School of Medicine at Mount Sinai, where she was also chief resident. She completed her gastroenterology fellowship at Mount Sinai Hospital and was also chief fellow.