A Complete Guide to Intermittent Fasting In recent years, intermittent fasting (IF) has become a popular dietary strategy that places more emphasis london sattaon when to eat than what to eat. Fundamentally, intermittent fasting is alternating between eating & fasting times to give the body the opportunity to achieve metabolic flexibility. It's a pattern of eating that can be tailored to suit different lifestyles, not a diet in the conventional sense.