Hi. I’m on day 7 of my first extended fast. The first 3.5 days were rough, but since then I’ve felt great. I’ve read Jason Fung’s Obesity Code, which is what inspired me to try this, and I’m glad I did. I’m doing it mainly for weight loss and ancillary benefits (reducing Type 2 diabetes risk, etc.)
One question I have is how quickly I’ve lost weight. I’ve lost 11 lbs in a week. Of course I’m happy with this, but I remember hearing many times that more than 2 lbs per week is dangerous. This has usually been mentioned with typical restriction diets (e.g. calorie restriction). But it doesn’t seem to apply to fasting, given Fung’s book and various studies published in medical journals.
The fears seem to categorize as:
- Malnutrition - But fasts are short term and nutrients can be supplemented. However, the longest medically supervised fast involved only water and electrolytes
- Loss of lean tissue - Fung seems to dispense with this myth showing that muscle loss is less in fasting compared to low calorie diets
- Rebound weight gain - This would depend what you do afterwards. I’ve done ketogenic before and plan to transition into that after the fast. When I don’t do ketogenic, I’m still eating healthy whole foods and low carb.
- Blood sugar instability - I check my blood sugar at home and it’s been normal, 91 mg/dL
- Electrolyte imbalances - Again, this doesn’t seem to be indicated as a problem with fasting. I take an electrolyte supplement tablet anyway.
This Lancet study seems to contradict the rapid weight loss idea:
Any insights on this? Am I missing something?