Dr. Jason Fung: Fasting as a Therapeutic Option for Weight Loss

ByCrossFit July 27, 2019

Dr. Jason Fung, MD, is a nephrologist and expert in the use of intermittent fasting and low-carbohydrate diets for the treatment of Type 2 diabetes. In this presentation, delivered on Aug. 2, 2018, at the 2018 CrossFit Health Conference in Madison, Wisconsin, Fung shares his first-hand experiences navigating a broken healthcare system and discusses how he shifted his research and medical practices as a result.

Fung’s objectives for his presentation include:

  • Understanding why long-term weight loss is so difficult.
  • Introducing the concept of therapeutic fasting.
  • Understanding some myths and misunderstandings associated with the fasting process.

He recalls treating obese and diabetic patients with traditional methods, which included what he characterizes as poor dietary recommendations and a slurry of drugs. He explains, “It became obvious that I’m just sort of holding their hand until they get their heart attack, until they get dialysis, until they go blind, until we chop their feet off.”

“It’s really sad to realize that the profession that you’ve chosen is not really helping people,” he says. This realization compelled him to diagnose the problems associated with traditional care and seek alternative treatment methods for his patients.

Fung historicizes what he calls “the modern eating pattern,” which emerged in 1977 in the U.S. with the development of the Dietary Guidelines for Americans. He notes the 1977 guidelines led to the consumption of more grains and sugars, which in turn led to people “eating often, eating late, and eating all the time.”

Incidences of obesity and Type 2 diabetes reached epidemic levels, and the most common treatments have long been drug interventions. Unfortunately, the prevailing non-pharmaceutical prescription — to eat less and move more — has a 99.9% failure rate. Fung observes that popular wisdom tells us to blame the patients and assume they did not adhere to the prescription. He claims a basic understanding of metabolism suggests otherwise, however.

He also explains why intermittent fasting is an effective alternative to traditional treatments for obesity and diabetes. The modern eating pattern keeps our insulin levels high all the time as we eat over long durations, and when insulin remains high all the time, Fung explains, our bodies store food energy as fat. Even when losing weight on a calorie-restrictive diet, the metabolism will slow, hunger hormones will increase, and the weight will eventually return. Intermittent fasting, on the other hand, allows insulin levels to drop, which puts us in burning mode rather than storing mode, and allows for greater hormonal control of energy partitioning.

Fung claims his recommendations are so effective that patients no longer need to say, “I have to go see my doctor to see what pill I need,” or, “I need to go see my doctor to see if he needs to stick a stent in me.” Instead, Fung explains, “We’re giving you the power to take back your own health, because you’re not gonna get it from anywhere else.”