Has postponing dinner become the norm for you? Whether it’s for a good reason, such as going to the gym after work, or one that’s less in your control, such as business or even family obligations, eating a late dinner and going to sleep on a full stomach may lead to more than a familiar feeling of indigestion, according to a study done by Barcelona Institute for Global Health in Sapin.

It could lead to cancer.

The study: Researchers looked at the eating habits of 4,000 people who took part in the larger MCC-Spain project that is investigating numerous environmental risk factors for cancer. Participants included prostate cancer patients, breast cancer patients and men and with no history of these cancers.

All participants answered questions about their eating and sleeping habits and completed a questionnaire on how well they followed cancer-prevention recommendations such as maintaining a healthy body weight, engaging in regular physical activity and eating more vegetables and less meat. The researchers also assessed each participant’s chronotype—whether he/she was a morning person or a night owl, indicators of whether someone is more likely to start (and finish) eating earlier or later in the day.

The findings: The researchers found a definite connection between the timing of dinner and sleep and cancer risk. Participants who ate dinner before 9 pm and waited at least two hours after eating to go to sleep had, on average, a 20% lower risk for breast and prostate cancers combined compared with those who ate dinner after 10 pm or who ate and went to bed soon afterward (on a full stomach). “Morning people,” those who are more active early in the day and eat meals earlier than “night owls,” had the lowest risk.

Researchers still are trying to understand the mechanisms through which the late timing of dinner may affect cancer—one mechanism likely is inflammation—and this is a new area for research, said Dr. Kogevinas.

What this means for you: While the study took place in Spain where eating dinner late is part of the culture, many people in the US push dinnertime late into the evening more out of necessity. Even though current recommendations about healthy eating to avoid cancer don’t take the timing of meals into account, these findings suggest that maybe they should, says the study’s lead author Manolis Kogevinas, MD, PhD. Plus, we already know from previous research that late-night meals can cause us to pack on pounds, make it hard to sleep and set us up for heart disease and diabetes, Dr. Kogevinas said. So eating dinner earlier can benefit you in many ways.

Here are other health-related dining suggestions gleaned from the research…

  • Skip the bedtime snack. Eating even a small amount before you go to sleep may trigger the same negative process that occurs when you eat a late dinner, Dr. Kogevinas said.
  • If you have to eat dinner late, keep it light—healthful foods in small portions.
  • Even if you’re a confirmed night owl, aim to eat like a morning person with the health adage “Eat breakfast like a king, lunch like a prince and dinner like a pauper.”