What's the relation between extreme hunger and intermittent fasting?

Hunger is a great indicator of whether you are doing intermittent correctly. If the hunger is too high and severe WITH additional blood sugar issues (dizziness, lightheadedness, irritability, sugar cravings, and brain fog), then you need to cut back and add a meal or add more fat with a meal.

The other thing to do is add electrolytes to your fasting period and some bone broth as this will make it easier to go from 1 meal to the next. If you just have some hunger and it's not too severe - ride the wave and keep going.