So how long do they recommend the fast to be and how many days a week etc. Also how is one supposed to work or clean house when they are weak from not eating?
I fast 18 hours and eat during 6 hours each day. I never feel weak. It’s actually easier to clean house or workout while fasting than on a full stomach.
Lots of different options. Each person has to find their sweet spot. Some people fast 16 - 20 hours daily with one or two meals a day. Some people do alternate day fasting. Some do a down day of 500 calories followed by a regular day of eating at least 1500 calories.
Fast, Feast, Repeat by Gin Stephens has a good overview of the science and how to ideas.