Fasting Q&A with Dr Jason Fung: Order of Fat Burning, Fasting With a Gastric Sleeve, BMR Fluctuation, GLP-1 Drugs, and More

The Fasting Method

July 30, 2024

Episode #163

In this Fasting Q&A episode, hosted by Coach Lisa Chance, Dr. Jason Fung answers questions from the TFM Community:

1. I have a Lumen device and they talk about a fasting ‘sweet spot’. They say that if you fast for too long, then your body might get stressed and go back into carb burning, and that if you test with the Lumen every two hours, you can see this switch from carb burning to fat burning and then possibly back to carb burning – in which case it could be a good idea to stop the fast, perhaps doing more shorter fasts to maximize fat burning. Is this true? [01:57]

2. I have heard conflicting reports about lemon in water and herbal teas breaking your fast. Do they will interfere with autophagy, if that is your main goal? [08:47]

3. Is it known if there is an order in which fat is burned during fasting? For example, is the recently-gained fat burned first and the oldest last, or visceral vs subcutaneous? [10:52]

4. My doctor is not discouraging fasting but dismissed it as another means of cutting calories. How can I explain concisely why fasting works but calorie reduction diets don’t? [13:55]

5. What are your thoughts on using GLP-1 drugs in conjunction with fasting? [21:25]

6. Any suggestions for successful fasting protocols for individuals, post gastric sleeve (3 years)? [23:45]

7. In his book The Obesity Code, Dr. Jason Fung explains that a large percentage of obesity is genetically determined. Could the outcome of the research also be explained by us getting addicted to sugar before we are born if our mother consumes sugar? [24:56]

8. Since fish oil contains no protein and thus should not trigger mTOR, isn’t it the best fasting aid as it is both and-inflammatory and calming? [29:38]

9. I know that in some studies in the past they have showed that not having an “up day” after a full fasting day in ADF would lead to a decrease in BMR. Do we still believe this to be true? If I did a 48-hour fast, ate one meal, and then fasted for 24 hours right after, and it wasn’t difficult, am I ultimately decreasing my BMR? [30:37]