Watched a video on fasting, these are my main insights in form of a short notes. I should read a book from this guy.

Jason Fung: The Complete Guide to Fasting (& how to burn fat) - YouTube


1. Lean vs. obese fasting

If you’re lean, after day’s fast body’s energy is coming form 70% of fat. If you’re obese, it’s 90%+ of fat. Does not mean lean people don’t benefit from fasting, but may consider shrinking the fasting window from 36 hours to e.g. 16–20 (Intermittent fasting).

2. Loss of muscle?

If you fast for more than 16 hours you indeed can start to break down proteins, but it’s totally fine because you rebuild more fresh and better ones after having a good meal when breaking the fast and when your growth hormone secretion has been spiking.

Fasting is 4 times better at preserving lean muscle vs caloric restriction.

3. Satiety mechanisms

Automatic satiety mechanisms are bypassed by high-carb foods and drinks e.g.:

  • Stretch receptors
  • Cholecystokinin

4. Waist fast

Fat around waist is the dangerous thing. Waist to heigh ratio must be kept below 0.5.

5. Fasting portability

Mix fasting with diets: vegan, keto.