Dr. William Yancy, MD

Will Yancy_round

Dr. William Yancy, MD, is an internal medicine doctor, obesity medicine specialist, and researcher. He is a Fellow of The Obesity Society and a diplomate of the American Board of Obesity Medicine.

Dr. Yancy has spent most of his career researching obesity and treatments for obesity. He is an associate professor of medicine at Duke University and a staff physician and a researcher at the Durham VA Medical Center.

He is also the director at Duke Diet and Fitness Center, an immersive, residential-style, comprehensive weight management program that serves patients from around the world who come to Duke for a week or longer to change their eating and activity lifestyles, lose weight, improve their health and learn strategies for long-term success.

Dr. Yancy has conducted multiple clinical trials investigating how different dietary and medicinal approaches affect body weight, cardiovascular risk, and diabetes, with particular expertise regarding low-carbohydrate eating.1

He has also performed a number of studies examining innovative approaches toward improving adherence to lifestyle recommendations and other treatments.

Dr. Yancy’s been featured in The New York Times, Prevention, Science Daily, and more.

Select scholarly publications

Dr. Yancy has published over 100 peer-reviewed scientific articles. Since 2010, these are a few of his most notable:

Yancy WS, Jr, Westman EC, McDuffie JR, Grambow SC, Jeffreys AS, Bolton J, Chalecki A, Oddone EZ. A randomized trial of a low-carbohydrate, ketogenic diet versus orlistat plus a low-fat diet for weight lossArch Intern Med  2010;170(2):136-145.

Mayer SB, Jeffreys AS, Olsen MK, McDuffie JR, Feinglos MN, Yancy WS, Jr. Two diets with different hemoglobin a1c and antiglycemic medication effects despite similar weight loss in type 2 diabetes. Diabetes Obes Metab. 2014;16(1):90-3

Yancy WS Jr, Mayer SB, Coffman CJ, Smith VA, Kolotkin RL, Geiselman PJ, McVay MA, Oddone EZ, Voils CI. Effect of allowing choice of diet on weight loss: a randomized trialAnn Intern Med. 2015;162(12):805-14

Evert AB, Dennison M, Gardner CD, Garvey WT, Lau KHK, MacLeod J, Mitri J, Pereira RF, Rawlings K, Robinson S, Saslow L, Uelmen S, Urbanski PB, Yancy WS, Jr. Nutrition therapy for adults with diabetes or prediabetes: a consensus reportDiabetes Care. 2019;42(5):731-754

Yancy WS, Jr, Crowley MJ, Dar MS, Coffman CJ, Jeffreys AS, Maciejewski ML, Voils CI, Barton AB, Edelman D. Group medical visits combined with intensive weight management for type 2 diabetes: a non-inferiority randomized trialJAMA Intern Med. 2019;180(1):70-9.

Dr. Yancy’s Awards

He has received several awards for his research. To name a few:

Dr. Yancy received his medical degree from East Carolina University and completed his residency at the University of Pittsburgh. He also has a Masters in Health Sciences from Duke University.

You can also find Dr. Yancy on Twitter and LinkedIn.


    Is there science to support low carb?

Medically reviewed evidence-based guides for Diet Doctor

How to lose belly fat

Bariatric surgery for metabolic health and weight loss

What to do about constipation on a low-carb or keto diet

Aiming to understand the dawn effect

How low carb is keto?

14-day low-carb diet plan

Potential conflicts of interest

Dr. Yancy eats a whole foods diet emphasizing foods lower in carbohydrate and higher in protein, fat, and fiber. He also believes that physical activity is important to health.

He also has a contract agreement with DietDoctor.com to review guides and news stories for clinical accuracy and appropriate interpretation of evidence. He receives payment for his reviews.

Dr. Yancy has had other an unpaid, voluntary roles for:

  • American Diabetes Association, as a nutrition recommendation writing committee member
  • American Board of Obesity Medicine, as an item writing committee member
  • The Obesity Society, American Diabetes Association and multiple scientific journals, as an abstract and article reviewer


Team Diet Doctor