David S. Ludwig, MD, PhD, is a practicing endocrinologist, researcher, and professor at Harvard Medical School and Harvard School of Public Health. He received a PhD and an MD from Stanford University School of Medicine and completed an internship and residency in pediatrics and a fellowship in pediatric endocrinology at Boston Children's Hospital.

Dr. Ludwig also directs the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital. His research focuses on the effects of diet on hormones, metabolism and body weight. He developed a novel “low glycemic load” diet (i.e., one that decreases the surge in blood sugar after meals) for the treatment of obesity-related diseases. In addition, his group has done some of the original studies linking sugar-sweetened beverages and fast food to excessive weight gain, heart disease and type 2 diabetes.

Described as an “obesity warrior” by Time magazine, Dr. Ludwig has fought for fundamental policy changes to restrict junk food advertising directed at young children, improve the quality of national nutrition programs, and increase insurance reimbursement for obesity prevention and treatment.

Dr. Ludwig is Principal Investigator on numerous grants from the National Institutes of Health, has published over 150 scientific articles, and served for 10 years as Contributing Writer for JAMA. He has also written several books for the public, including 'Ending The Food Fight' (2007), 'Always Hungry?' (2016) and the cookbook 'Always Delicious' (2018).

Dr David Ludwig's lecture on the Carbohydrate-Insulin Model of Obesity for the Nutrition Seminar Series, Harvard School of Public Health.

Diet doesn't have to mean deprivation, and weight loss doesn't have to be temporary. 

Based on the over 150+ scientific studies I've conducted, and several hundred other referenced in the book, Always Hungry? turns dieting on its head with a three-phase program that ignores calories and targets fat cells directly. The recipes and meal plan include luscious high fat foods (like nuts and nut butters, full fat dairy, avocados, and dark chocolate), savory proteins, and natural carbohydrates. The result? Fat cells release their excess calories and you lose weight-and inches-without battling cravings and constant hunger.

Forget calories. Forget cravings. Forget dieting. ALWAYS HUNGRY? reveals a liberating new way to tame hunger and lose weight... for good.

Do foods with the same calories have the same metabolic effect? Dr. David Ludwig did a study to help us better understand the role of calories.

In the messy world of nutritional science, some researchers rise above the others in their attempt to produce high quality and useful data. Dr. Ludwig exemplifies that role. As a practicing pediatric endocrinologist, he has seen first hand the rise in obesity, type 2 diabetes, fatty liver and other previously rare complications in adolescents. 

As a result, he has made it his mission to help us better understand the role of calories, the importance of quality of calories, and the importance of the quality of the science we read. Is a calorie just a calorie? Why are so many scientific studies not helpful in answering this question, and what can we do about that? Dr. Ludwig answers these questions and more.