Intermittent Fasting (IF) is a way of structuring your eating patterns.

IF can be done in many ways, the most common being a 16:8 ratio. This means for 16 hours you eat no food, and instead fit all of your macros into an 8 hour window.

By fasting for such a long period, you deplete your glycogen stores and force your body to use fat for fuel.

This means you are not storing fat, you are burning it, and you also increase your Human Growth Hormone. This is extremely important for protein synthesis. 

Related Questions:

1. Erica's article on IF