MEET
Created by Dr. Andrew Keyser and Britt Cables, NP to bring a better way of caring for people — one that focuses on prevention, longevity, and feeling good in your body.
After years inside traditional medicine, they saw how rushed, reactive, and disconnected care had become. The kind of thoughtful, high-touch care that works was only available through private doctors and elite clinics.
DefineMD brings that level of care into a modern, built for you, program.
Dr. Andrew Keyser
Andrew Keyser, MD is an emergency medicine physician and the Co-founder of DefineMD. After years on the front lines of care, he saw firsthand how often traditional medicine steps in too late—treating disease rather than helping people understand their health and prevent long-term decline.
Dr. Keyser built DefineMD to offer a more intentional approach to care—one centered on education, prevention, and personalized treatment. His work focuses on weight management, sexual health, and whole-person wellness, helping patients make informed, sustainable decisions that support both how they feel today and their long-term health.
Married to a pediatrician and raising two children, Dr. Keyser is deeply committed to advancing a model of medicine that supports patients across every stage of life. DefineMD reflects that vision: thoughtful, relationship-driven care designed to help people feel better and live healthier, longer lives.
Robin Lee, RD
Robin Lee, RD is a registered dietitian who specializes in building sustainable, realistic habits for weight loss and blood sugar control. Robin has extensive experience, having previously been a dietician with industry leading Telehealth weight loss brands. She brings a supportive, behavior-based approach that focuses on progress—not perfection.
She specializes in working with people with pre-diabetes and those looking to lose weight in a healthy, maintainable way. Robin believes nutrition should fit into real life and creates personalized plans that feel doable, enjoyable, and empowering. She lives in Colorado and enjoys hiking and being outdoors with her husband, two daughter and three dogs.
Britt Cables, FNP
Britt Cables, FNP, co-founder of the Define MD team, where care is personal, compassionate, and centered on the whole individual. She is certified in obesity medicine and brings a strong focus on identifying root causes and creating thoughtful, individualized treatment plans—meeting patients where they are and supporting sustainable progress over time.
Britt believes great medicine starts with connection. She practices relationship-based, concierge-style care that prioritizes listening, trust, and real-life solutions—offering an experience that feels refreshingly human and deeply personalized.
Outside the clinic, Britt is a devoted dog lover, a proud mom to college-age kids, and an avid traveler. She’s currently learning to ski (embracing the learning curve) and enjoys exploring new places, trying new things, and continuing to grow both personally and professionally.