Intermittent fasting or IF is a weight-loss plan where you restrict when, or how much, you eat instead of what you eat. There are different types of IF. They either involve limiting the time you eat to a certain window every day, or drastically restricting your caloric intake on certain days of the week.

Natalie Allen, a registered dietitian and clinical instructor of biomedical sciences at Missouri State University, highlights the different types of IF, and their pros and cons to Insider.