What is the best fasting window for someone over 40?

I think the best pattern to start out with is the 18 hour fast and then the six hour window. That gives you this real easy thing to do by just skipping your breakfast. And that's easy to do because most people are not as hungry as they think in the morning. And even if they are, it's a hunger wave that goes away if they just ignore it, because really they have this little spike in cortisol.

But if you can do an 18 hours you'll have so many amazing benefits. So after six o'clock, you just fast all the way to the next day until 12 and you have this wonderful period of autophagy and you see all these amazing benefits. That would be like the average great fasting window for someone over 40.

Now, if someone's a little more hardcore and they want to see faster results and they want to bite the bullet, what you do is you push them right to a 20 hour fast. So now we have a four hour window of eating and then 20 hours of fasting. Then you're going to see some even better benefits, especially with the immune system.