Say if I do a 4 day water fast. Then eat normally for 2 days, and follow that with another 3 day water fast. Is that the same as doing a straight 7 day fast?
No, as two of those seven days, instead of one, will be necessary to get to to a fasted state.
But if it helps you do this before you go for a longer fast, go for it, big victories come with small steps.
This is difficult to answer.
Autophagy peaks at appx 72 hours. None of the studies I have read indicate when it tapers off. Perhaps someone else has that data.
If your goal is mental health then
You can achieve and stay in fat burning mode by fat fasting between spikes. People who do OMAD do very well by fat fasting one meal a day. If you do this then you burn fat you eat then the fat on your body but the glucose spikes are lower.
Your body only burns glucose or fat. A healthy body can switch back and forth between fat burning and glucose burning fairly easily this is called being fat adapted.
Eat food that you don’t have a reaction too is just as important as the fasting. E.g. when I eat yams my glucose spikes and stays high an hour longer than if I eat a sweet potato. They are very similar but my body reacts differently to them. I don’t eat yams.
Back to point 1. Personally I do better with rolling 42 or 48s with an occasional 72 hour fast. I never fast more than 3 or 4 days in a week, because I think you need to eat in between to keep your body out of triggering starvation mode and refeeding, is much easier with shorter fasts.
Is a one week fast bad for you. No one but you can answer that. Do you get more benefit for autophagy or increased HGH … maybe, not sure on this. My logic is based on my goals for longevity…. 72 hrs. 1x a month with 42/46s works for me on a health and social level.
I don’t understand long fasts nor do I get super energetic with them. And this is how my body works. Other people love long fasts and report that they do well on them.
You have to decide what works for you on a long-term basis. Fasting is NOT a quick fix and boom go back to eating sugar and junk food. That would be binge eating.
Fasting is a lifestyle change that works with your body and has many great benefits.
Food luck with whatever you decide to do and keep us posted.