Lactose Intolerance
ALL LACTOSE INTOLERANCE ARTICLES





Yuying Luo, MD
Medical Reviewer
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.

Sanjai Sinha, MD
Medical Reviewer
Dr. Sinha did his undergraduate training at the University of California in Berkeley, where he graduated magna cum laude. He earned his medical degree at the Albert Einstein College of Medicine in New York City in 1998 and completed his internship and residency training at the New York University School of Medicine in 2001. Subsequently, he worked with the Department of Veterans Affairs from 2001 to 2012 and held faculty appointments at both the Mount Sinai School of Medicine and Columbia University College of Physicians and Surgeons.
In 2006, he won the VISN3 Network Director Award for Public Service and a commendation from the secretary of Veterans Affairs for his relief work after Hurricane Katrina. He joined Weill Cornell Medical College in 2012, where he is an assistant professor of clinical medicine and the director of the care management program, as well as a practicing physician.
In addition to his work for Everyday Health, Sinha has written for various publications, including Sharecare and Drugs.com; published numerous papers in peer-reviewed medical journals, such as the Journal of General Internal Medicine; and presented at national conferences on many healthcare delivery topics. He is a fellow of the American College of Physicians.

Reyna Franco, RDN
Medical Reviewer
Reyna Franco, RDN, is a New York City–based dietitian-nutritionist, certified specialist in sports dietetics, and certified personal trainer. She is a diplomate of the American College of Lifestyle Medicine and has a master's degree in nutrition and exercise physiology from Columbia University.
In her private practice, she provides medical nutrition therapy for weight management, sports nutrition, diabetes, cardiac disease, renal disease, gastrointestinal disorders, cancer, food allergies, eating disorders, and childhood nutrition. To serve her diverse patients, she demonstrates cultural sensitivity and knowledge of customary food practices. She applies the tenets of lifestyle medicine to reduce the risk of chronic disease and improve health outcomes for her patients.
Franco is also a corporate wellness consultant who conducts wellness counseling and seminars for organizations of every size. She taught sports nutrition to medical students at the Albert Einstein College of Medicine, taught life cycle nutrition and nutrition counseling to undergraduate students at LaGuardia Community College, and precepts nutrition students and interns. She created the sports nutrition rotation for the New York Distance Dietetic Internship program.
She is the chair of the American College of Lifestyle Medicine's Registered Dietitian-Nutritionist Member Interest Group. She is also the treasurer and secretary of the New York State Academy of Nutrition and Dietetics, having previously served in many other leadership roles for the organization, including as past president, awards committee chair, and grant committee chair, among others. She is active in the local Greater New York Dietetic Association and Long Island Academy of Nutrition and Dietetics, too.

Natalia Johnsen, MD
Medical Reviewer
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.

Michelle Seguin, MD
Medical Reviewer
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.
- Lactose Intolerance. Johns Hopkins Medicine.