Intermittent fasting simply refers to an eating pattern that cycles between periods of fasting (not eating) and periods of eating.
The best way to start intermittent fasting is by simply cutting out snacks and only eating 3 meals a day - that's it!
After you're in the groove of doing 3 keto meals a day with no snacking (typically 2 to 3 weeks), try to wait an extra hour before eating breakfast.
One thing fasting is not, is a reduced-calorie or starvation diet! When fasting, each time you cut out a meal, you need to increase the size of your other meals.
Allowed liquids when fasting
Any liquids that don't trigger insulin are allowed when fasting. So you'll need to avoid carbs and protein (except protein in extremely small amounts, such as in bone broth).