Our Scientific Advisory Council members are experts in a wide array of wellness topics. They bring health and wellness knowledge from different disciplines and advise us as we develop innovative products and programs.


John is the Chairman of Onlife Health’s Scientific Advisory Council.  He is the Clinical Professor of Medicine at the University of California, San Francisco and the Clinical Professor of Health and Medical Sciences at the University of California, Berkeley.  He’s an Editorial Board Member at the American Journal of Medical Quality and is a co-author of “The Wellness Self-Care Handbook” and “The Complete Home Wellness Handbook.”

Dr. Guenther is a Research Professor in the Department of Nutrition and Integrative Physiology, College of Health, University of Utah. From 2003 to 2013, she was a nutritionist at the US Department of Agriculture’s Center for Nutrition Policy and Promotion, where she led the 2005 and 2010 revisions of the Healthy Eating Index and conducted other research related to dietary assessment and the Dietary Guidelines for Americans. Dr. Guenther is a registered dietitian, member of the Academy of Nutrition and Dietetics and of the American Society for Nutrition, and serves on the editorial board of the Journal of the Academy of Nutrition and Dietetics.

David is Associate Professor of Psychology at Vanderbilt University where he specializes in the psychology of change, particularly, how racial, ethnic and environmental factors influence lifestyle behaviors affecting eating, exercise and smoking. He is a member of the Vanderbilt Diabetes Research and Training Center, and works with the Vanderbilt Ingram Cancer Center, and the Vanderbilt Institute of Community and Translation Research. His research has examined how community action, public policy, and environmental change can be used to promote healthy eating and exercise.  

Jamie is a Registered Dietician and Instructor of Nutrition at Vanderbilt University School of Nursing.

She holds a master’s degree in Nutrition Science and is member of the Academy of Nutrition and Dietetics. She is a recognized authority in the areas of nutrition and health promotion, obesity and weight management, and heart disease prevention and has authored or contributed to best-selling books including The Last Five Pounds: A Liberating Guide to Living Thin, an introductory nutrition textbook, and The T-Factor Fat Gram Counter

Dr. Weaver is a Corporate Medical Director at Blue Cross Blue Shield of Tennessee.  In this role, she serves as clinical interface with the provider community as well as medical director level support for the company’s group accounts, provider network management, innovations and sales/marketing teams. 

Dr. Weaver is an active Diplomat for both the American Board of Family Medicine and American Board of Preventive Medicine.  With over 20 years of clinical experience she has served as an Associate Professor in the Meharry Medical College Department of Family and Preventive Medicine. Dr. Weaver currently serves on the Meharry Preventive Medicine Residency Advisory Committee and is an Advisor for multiple community health advisory boards.  Prior to her medical training, Dr. Weaver received her Master’s Degree in Psychology and served as a Psychological Examiner.