Intermittent Fasting (IF) refers to the general practice of extending the amount of time in between feeding vs the typical Western feeding schedule of 3 meals equally interspersed in a day . It is also sometimes referred to as time-restricted feeding (TRE). Adherents of intermittent fasting believe it helps burn fat, improves general health, and potentially slows aging by activating gene pathways similar to those of caloric restriction (CR).
There are many variations on intermittent with different schedules of feeding vs non-feeding times. Some of the most popularly practiced variations include:
16:8 - 16 hours fasting followed by an 8 hour feeding window.
Circadian fast - Eat only during an 8 - 10 hour window during daytime.
OMAD - One meal a day.
5:2 - 5 days of regular feeding followed by two days full days fasting.
7-day / quarter - A week long fast once every 3 months.
KFK - A period of ketosis, followed by a fast, then another period of ketosis.