What's the worst type of fasting?

Alternate day fasting is when you would fast for one day, and then the next day, you would eat whatever you wanted. There is also a version of this pattern where you're actually still consuming about 500 calories on the days that you're fasting.

With the 5:2 fasting pattern, you can eat whatever you want for five days, and then you fast for two days. This pattern also allows you to have about 500 calories on the days that you're fasting. These two patterns of fasting are bad because it takes 3-7 days to get into ketosis.

Fasting for 1-2 days is not long enough to get into ketosis, especially when you're actually still consuming 500 calories.

With these fasting patterns, you won't generate enough ketones for your brain to feel good. You could end up miserable, hungry, grouchy, and you could have cravings.

Fasting patterns that I believe work are the:

• 18:6 — Fasting for 18 hours with a 6-hour eating window.

• 20:4 (even better) — Fasting for 20 hours with a 4-hour eating window.

These fasting patterns can produce a lot of benefits.

You also:

• Won't be hungry

• Won't have cravings

• Won't be grouchy