41: How to Fast for a Faster Metabolism | Jason Fung, MD

Fasting Protocols

Fasting protocols offer a structured approach to eating and fasting that can enhance metabolic health. Jason Fung explains that traditional fasting, such as the 12-hour overnight fast, was once a natural part of daily life, but modern habits have extended eating periods to nearly 15 hours a day 1. This constant eating disrupts the body's natural cycle of burning stored energy. To counteract this, Fung suggests protocols like the 16:8 diet, where one fasts for 16 hours and eats during an 8-hour window, or even a 24-hour fast once or twice a week 1.

12 hours was sort of the baseline that they did in the seventies. And guess what? There's just not very much obesity.

--- Jason Fung

While water-only fasting is ideal, Fung notes that coffee without additives is generally acceptable for those fasting primarily for weight loss, as it doesn't significantly impact insulin levels 2.

   

Dietary Adjustments

Dietary adjustments play a crucial role in supporting health and weight loss goals. Jason Fung advises against high protein diets for most people, suggesting that the recommended daily allowance is sufficient for maintaining health 3. He emphasizes that excessive protein intake can interfere with ketosis, a state beneficial for weight loss.

There's no evidence that somebody who is otherwise healthy eating a lot of protein is going to damage the kidneys.

--- Jason Fung

Regarding fruit consumption, Fung warns about the increased sweetness of modern fruits, which contain more sugar than in the past. While fruit is not the primary cause of obesity, he recommends moderation for those struggling with weight or insulin resistance 4.