Time-restricted eating (TRE) is defined as a dietary regimen that restricts eating to specific hours of the day, and then fasting the rest of the time. TRE has become extremely popular for weight loss since it reduces blood sugar levels during the fasting hours and forces the body to pull fat from storage to be used as fuel once the body's available energy (such as glycogen stored in the liver, muscles, and other cells) is used up.

Time-restricted eating means eating within a specific time window—12,10, or 8 hours—and not eating the other 12, 14, or 16 hours of the day. That’s why the first meal of the day is called breakfast: We break the fast. If you eat dinner at 6 p.m. and breakfast at 8 a.m., that’s a 14-hour fast.

Snacking and late-night eating interferes with your body’s ability to rest, repair, and regenerate. Time-restricted eating doesn’t restrict calories; it limits your feeding window to optimize repair. For example, you might consume all of your meals between 7 a.m. and 3 p.m., or 7 a.m. and 5 p.m.