A new study brings to light the negative health effects of late-night eating.
In a scene from the hit TV show Mad Men, Don Draper and coworker Harry Crane go to White Castle for a late-night snack after a Rolling Stones concert. Don watches in disgust as Harry downs 20 sliders and doesn’t save any to bring to his family. “Let them get their own,” Harry says. “You bring home a bag of food and they go at it and there's nothing left for you? Eat first.”
Harry may have thought he was looking out for himself, but he was really doing his kids a favor by preventing them from late-night eating fests—and tanking his health (he consumed about 2,800 calories and 120g fat in that one sitting).
A new study from Barcelona published in the International Journal of Cancer looked at more than 4,000 people and found those who had their last meal before 9 p.m. or at least two hours before they went to bed had a 20 percent lower risk of breast or prostate cancer.
The researchers think eating late boosts cancer risks because going to sleep soon after eating affects your ability to metabolize food—and that can trigger cancer-promoting inflammation. They also suggest that it’s no healthier to eat late and then push your natural bed time later. Past research has found that disruption in circadian rhythm is also linked to a higher risk of cancer.
The best timing for overall health and weight control? Research indicates the ideal break between dinner and breakfast may be 13-plus hours.
Medically reviewed in September 2019.