Intermittent fastingIF · Time-restricted eating

Intermittent fasting is a family of eating patterns defined by when you eat rather than what. The common forms are time-restricted eating — compressing food into a window of, say, eight or ten hours — alternate-day fasting, and the 5:2 pattern of two heavily restricted days a week.

It matters because it is one of the better-studied eating patterns of the last decade, and the finding is consistent: when calories and protein are matched, it produces fat loss comparable to continuous restriction, not better. Its value is as an adherence tool — for people who find a shorter eating window easier than counting — plus modest, less certain benefits to glucose control.

In practice the main caution is protein: a narrow window makes it harder to reach an adequate daily intake, which matters if you are training and want to keep muscle. It is also a poor fit for people with a history of disordered eating, and pregnant or breastfeeding people should not attempt it without medical advice.