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We're changing the way the world treats weight.

We’re in this together.

Lasting weight loss and metabolic health takes the right team. Our doctors, coaches, specialists, and advisory board members work together to ensure you’re supported through every victory, setback, and comeback.

Small wins create big wins.

We want long-term results for every Calibrate member, so everything we do is in service of creating enduring and empowering habits. We know that small, simple steps can add up to something much greater than its parts, so that’s what we do.

You’re in control.

Your Calibrate program fits your life and your progress, not the other way around. Throughout the year, you’ll connect regularly with your doctor and coach, making it easy for them to personalize your goals, cheer you on, and make adjustments in real-time.

Real results matter.

We don’t do instant gratification—because it doesn’t work long-term. The Calibrate program combines what’s been scientifically proven to lead to lasting results and, over the course of a year, helps you make it your new everyday.


Isabelle Kenyon

Founder & CEO

Isabelle is the Founder & CEO of Calibrate. Prior to Calibrate, she led the business operations, growth, and strategic partnerships & communications teams at Capsule, a technology business that has raised $570 million to rebuild the pharmacy from the inside out. Before Capsule, Isabelle worked at beloved consumer brands in London and New York and was selected to the Forbes 30 Under 30 Retail & E-commerce list in 2015. She began her career as an investment banker in Hong Kong and graduated from the University of Pennsylvania.

Our vision is to put you in control of your health. Calibrate is changing the way the world treats weight by bringing decades of proven metabolic science to everyone, everywhere.

Calibrate Program Team

As a Calibrate member, you will be in it together with a comprehensive team that supports you at every step of the way. The Coaching Team will be your day-to-day guides and cheerleaders, the Medical Team will ensure your metabolic health is improving, and the Support Team will make certain that every aspect of the Calibrate program runs seamlessly.

Kim Boyd, MD

Chief Medical Officer

Kim is a Stanford-trained physician with integrative medicine fellowship training, a functional medicine background, and ten years of healthcare startup experience. She was an early leader at One Medical, working on clinical systems, national expansion, and leading the virtual medical teams. Kim has also worked on the forefront of new models of medical care, having served as the Medical Director for Galileo and Nurx.

Calibrate gives people the understanding, tools, and support they need to take control of their health. With Calibrate's comprehensive program, not only does the weight on the scale go down, but the improvements in metabolic health—which affect everything from disease risk to mood and energy—set members up for healthier, happier lives.

Jim Geracci, MD

Chief Clinical Officer

Jim is a seasoned physician executive who has led healthcare innovation and transformation in some of the largest and most complex systems. He joins Calibrate from Optum (United Health) where he was CMO for Digital Health and Innovation/CEO of their Virtual Medical Group. Previously, Jim served as CMO in the Texas market of Ascension Healthcare and has over two decades of senior leadership experience in the military health system. Jim is a Fellow of the American Academy of Family Physicians, a graduate of the Uniformed Services University School of Medicine, and holds advanced degrees and certifications from US Army Command and General Staff College, Wharton, and Texas McCombs School of Business.

Results matter. At Calibrate we are obsessed with delivering results. The goal of our program is not just weight loss, but improvement in metabolic health and better health outcomes for our members.

Charmaine Stafford

SVP, Head of Member Experience

Charmaine is a seasoned customer experience, operations, and strategy leader. Prior to Calibrate she was SVP of Marketing and Customer Experience at Arise, where she designed and led the member experience for nearly one million users. Charmaine has held leadership positions for iconic brands including Starwood Hotels and Resorts (now Marriott), Intercontinental Hotels Group, and biometric identification company CLEAR. Charmaine earned a Bachelor’s Degree in Psychology and Organizational Behavior from the University of Pennsylvania and a Master’s Degree in Business Administration from Harvard Business School.

An incredible member experience is understanding and anticipating customer needs in order to delight and deliver beyond their wildest expectations.

Jane Ruppert, RDN, LDN, CDCES

SVP, Head of Coaching

Jane is a seasoned health and wellness leader joining Calibrate from Interactive Health, where she spent more than 13 years building the coaching organization. Jane is a Registered Dietitian Nutritionist and a Certified Diabetes Care and Education Specialist, earning her BS in Nutrition and Dietetics from the University of Illinois.

Through my career working in hospital systems and implementing employer wellness programs, I have seen the struggles individuals have to lose weight and keep it off. Calibrate provides a personalized treatment plan surrounded by a caring team of physicians and coaches to help individuals successfully lose weight and implement healthy habits for long-term success.

Expert Council

Calibrate's experts are leaders in their respective fields. They serve as a resource to your coach on how to develop your program so that it's personalized to you. They're supported by our clinical advisory board.

Adam Rosante

Calibrate Exercise Expert

Adam is one of the world's most sought-after strength and nutrition coaches. Privately, he works with A-list actors and athletes, getting them in shape to dominate on the screen and field. Publicly, he works with top-tier brands as well as the media to help people around the world live healthier, happier lives, including his role as a member of Shape magazine’s Board of Advisors. He's the founder of Good Eats, a not-for-profit that feeds underprivileged elementary school kids on the weekends, as well as Family Meal, a program that provides hot meals to families in need.

Studies have shown that consistent physical movement can lead to greater reductions in body fat mass—and this, in turn, drives favorable changes in metabolic health. Calibrate adjusts your physical activity levels to drive those improvements in metabolic fitness.

Stephanie Middleberg, RD

Calibrate Food Expert

Stephanie earned her Master's in Clinical Science and RD at New York University. She is the founder of Middleberg Nutrition, a health and wellness practice in New York City, and is the best-selling author of 'The Big Book of Organic Baby Food'. Her innate ability to zero in on individuals’ key food triggers has led to ongoing relationships with thousands of clients, editors, and publications, making her one of the country’s most sought-after health experts.

Resetting your metabolism isn’t just about calories in versus calories out. You have to take into account where those calories come from. Calibrate makes sure you’re getting the right nutrients through your diet so you can sustainably improve your metabolic health.

Emily Fletcher

Calibrate Sleep and Emotional Health Expert

Emily Fletcher is the founder of Ziva Meditation and the leading expert in meditation for extraordinary performance. Her book 'Stress Less, Accomplish More' debuted at #7 out of all books on Amazon. The New York Times, The Today Show, Vogue and ABC News have all featured Emily’s work. She’s been named one of the top 100 women in wellness to watch and has taught more than 20,000 students around the world.

The harsh reality is that stress is not only keeping us from performing at the top of our mental game, but it can also negatively impact our physical health. Calibrate introduces stress-reducing activities like meditation and sleep hygiene that can help heal your brain and your body, giving it the reset it needs.

Ellen Vora, MD

Calibrate Sleep and Emotional Health Expert

Ellen Vora graduated from Columbia University medical school, received her BA in English from Yale University, and is a board-certified psychiatrist, medical acupuncturist, and yoga teacher. Dr. Vora takes a functional medicine approach to mental health—considering the whole person and addressing imbalance at the root, rather than reflexively prescribing medication. In addition to her private practice, Dr. Vora is also a writer, speaker, and a consultant for healthcare startups.

One of the ways Calibrate helps to balance metabolic health is by supporting good sleep and a relaxed nervous system. When these are lacking, our metabolism adjusts to prepare us for famine and hard times—this promotes hunger, cravings, and the accumulation of visceral abdominal fat.

Christine Celio, PhD

Calibrate Emotional Health Expert

Christine Celio holds a Bachelor's degree and a Master's Degree from Stanford University, where she focused her studies on personal and social behavior change and received degrees in psychology, anthropology and sociology. She earned an additional Master's degree and a PhD in clinical psychology from Loyola University Chicago, where she specialized in neuropsychology and behavioral health.  In addition to treating individuals in psychotherapy, she consults for healthcare companies, serves as a speaker on supporting mental health for technology companies, and designs and evaluates behavioral health interventions in medical settings.

Having insight into what motivates you, identifying and living consistently with your values, is not only helpful for creating this new and healthy life, it is the way to sustain it. Calibrate's approach isn't a quick fix; it is a transformation.

Clinical Advisory Board

Calibrate’s clinical advisors are the top weight and metabolic health experts and scientific researchers in the country. They vet every aspect of our program to ensure we’re giving you the best possible guidance.

Donna Ryan, MD

Calibrate Clinical Advisor

  • President, World Obesity Federation, 2018-2020
  • Professor Emerita at Pennington Biomedical
  • Associate Editor-in-Chief of 'Obesity'
  • Investigator for various National Institutes of Health-sponsored studies, including Pounds Lost, DASH (Dietary Approaches to Stop Hypertension), DPP (Diabetes Prevention Program) and the Look AHEAD study

Dariush Mozaffarian, MD

Calibrate Clinical Advisor

  • Jean Mayer Professor of Nutrition the Tufts Friedman School of Nutrition Science and Policy
  • Cardiologist & Professor of Medicine at Tufts Medical School
  • Editor-in-Chief, Tufts Health & Nutrition Letter
  • Authored more than 400 scientific publications on dietary priorities for obesity, diabetes, and cardiovascular diseases, and on evidence-based policy approaches to reduce these burdens in the US and globally
  • Advisor to the US and Canadian governments, American Heart Association, World Health Organization, and United Nations

Fatima Cody Stanford, MD, MPH, MPA

Calibrate Clinical Advisor

  • Obesity medicine physician scientist, educator, and policy maker at Massachusetts General Hospital and Harvard Medical School
  • American Medical Association (AMA) Foundation Leadership Award recipient, Vice Chair to the Minority Affairs Section, Inspirational Physician Award recipient, and Health Policy Research Award recipient
  • Clinical expert on obesity for the United States Department of Health and Human Services Office of Women’s Health, the American Academy of Nutrition and Dietetics, the American College of Physicians, and the Robert Wood Johnson Foundation
  • Inaugural Director of Diversity for the Nutrition Obesity Research Center at Harvard

Randy Seeley, PhD

Calibrate Clinical Advisor

  • Henry King Ransom Endowed Professor of Surgery at the University of Michigan School of Medicine
  • Former Chair of the National Institutes of Health’s Integrative Physiology of Obesity and Diabetes review panel
  • Former Board of National Institutes of Health’s NIDDK Clinical Obesity Research Panel
  • Former Board of Reviewing Editors for 'Science'
  • Director of the NIH-funded Michigan Nutrition Obesity Research Center

Jamy Ard, MD

Calibrate Clinical Advisor

  • Co-Director of the Wake Forest Baptist Health Weight Management Center
  • Former Medical Director of University of Alabama EatRight Weight Management Services & Vice Chair for Clinical Care in the Department of Nutritional Sciences
  • Investigator for various US National Institutes of Health-sponsored studies, including Dietary Approaches to Stop Hypertension (DASH), DASH-sodium, and Weight Loss Maintenance Trial

Donald Williamson, PhD

Calibrate Clinical Advisor

  • Former Chief of Health Psychology and McIlhenny Endowed Professor of Nutrition and Current Professor Emeritus at the Pennington Biomedical Research Center
  • Primary investigator for National Institutes of Health-sponsored studies related to the prevention of weight gain in children and adolescents. Co-Primary Investigator for the NIH-sponsored CALERIE study. Key investigator for the NIH-sponsored Diabetes Prevention Program, Look AHEAD, and POUNDS Lost studies. And Primary investigator for three Department of Defense studies testing the efficacy of an internet-based weight management and physical fitness program

Christopher Still, DO

Calibrate Clinical Advisor

  • Professor of Medicine, Department of Clinical Sciences at Commonwealth School of Medicine
  • Former President, National Board of Physician Nutrition Specialists
  • Founding Member of the Board of Directors for the Obesity Action Coalition

Our Investors

Our partners believe in our mission as much as we do.

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