Thoughts on Intermittent Fasting

Introduction:

Intermittent fasting (IF) is promoted as a way to reduce weight, reduce belly fat and to detox your body. There are many ways to do it, including...

Time restricted eating, eg fast for 14 hours then eat between 8 am and 6 pm, a 10 hour window, also known as 14:10. My personal habit is a 9 hour window from 11 am to 8 pm, so 15:9. This sometimes extends to 10 pm...

One meal a day (OMAD) is a 23:1 system, ie one hour per day for eating, 23 hours for fasting. Sounds brutal to me...

Extended fasting, eg 24 hours or 36 hours without food. Drinks allowed are water, black coffee, tea without milk (I like green tea or peppermint tea). I do a 36 hour fast each week from Monday 8 pm to Wednesday 8 am. I seem to be reducing weight at about one pound per week using this method combined with a 9 hour eating window on other days.

Alternate day fasting (ADF): fast one day, eat the next. This is essentially a 36 hour fast every other day with a 12 hour eating window. For sample results, see:

I Lost 165 Pounds Using Alternate Day Fasting

Alternate day fasting - modified (ADFM): Same as ADF but with one 500 calorie meal on "fasting" days.

5:2 fasting: a variant on ADFM with 5 days of normal eating, 2 days (eg Tuesday and Friday) with only one 500 calorie meal.

Some words from Robert Lustig:

Intermittent fasting (IF) is a less painful way [than calorie restriction] of jacking up the same subcellular processes. By depriving your liver of calories for fourteen to sixteen hours per day, IF gives it a chance to activate AMP-kinase, suppress mTOR, increase autophagy, chew up some of the liver fat that's been stored, improve insulin resistance, and lower your insulin - the same outcomes that low-carb and ketogenic diets achieve. IF has also been shown to promote weight loss, blood glucose control, reduced inflammation, improvements in memory and stress resistance, slowed ageing, and longer life span. Each of these benefits is a manifestation of improvement in insulin sensitivity. In this way, your leptin won't drop so fast that you feel awful; and since insulin blocks leptin signalling, the lower your insulin levels go, the better your brain can see the leptin. This means your sympathetic nervous ratchets up, and you burn faster. All in all, most people find IF easier to adhere to long-term, and it's better for you.

~ Metabolical, page 209

[text captured on my phone using Google Lens - love it!]