In general, fasting involves the removal of some or all food and drink for a period of time. Although you can remove food altogether on fast days, some fasting patterns like the 5:2 diet allow you to consume up to around 25% of your calorie requirements in a day ( 8 ).

What is the process of fasting?

Essentially, fasting cleanses our body of toxins and forces cells into processes that are not usually stimulated when a steady stream of fuel from food is always present. When we fast, the body does not have its usual access to glucose, forcing the cells to resort to other means and materials to produce energy.

How do I start fasting?

If you're a beginner, start with a 24-hour fast: Eat dinner, and then refrain from eating until the next night. Be sure to drink plenty of water to prevent dehydration, and plan your fast for a nontraining day.