Last month, the American Heart Association released a new scientific statement that seemed to suggest that eating late in the day is bad for your heart. At least, that was the take home message that made the rounds on evening news and morning shows.
The actual statement was a bit more cautious: “Allocating more calories earlier in the day might help reduce cardiovascular disease risk,” it read. But that was immediately followed by the disclaimer that “large studies tracking patients’ cardiovascular health over a long period are needed to show how meal timing and patterns impact disease risk.” In other words, this is still very much an unanswered question.
If you are someone who eats dinner at 6 pm every night and doesn’t eat again until breakfast, you might be feeling pretty smug right now. But that’s a pretty small group of people. Most American households (including mine) eat dinner closer to 7 pm and their European counterparts tend to eat even later. And about half of adults (including this one) frequently snack between dinner and bedtime. The question is whether we need to change our behavior in response to this latest research.
What Does the Research on Meal Timing Show?
The first thing to understand is that this statement was not made in response to a new study. Rather, the authors looked back at studies that have already been done on different aspects of meal timing and meal frequency to see if they could draw any firm conclusions. And they really couldn’t—hence the disclaimer.
There were studies that found an association between late eating patterns and various cardiovascular risk factors—but, as the authors are careful to point out, correlation isn’t necessarily causation. Just because two things happen together does not necessarily mean that one causes the other. The few studies that actually tested the impact of different meal timing on risk factors tended to be small and short in duration--not the kind of thing that you can really hang your hat on.
Having read the entire review paper, which is available here if you’d like to take a look, my take away is a little different than what you may have seen on the evening news.
Is Eating Late Bad?
Our bodies do have daily (or circadian) rhythms that affect our digestion, metabolism, and hormonal systems. So it’s not a stretch to think the timing of your meals could affect your body’s response to the food. However, I think that what and how much you eat matters more than when you eat it. As the authors of this paper point out, simply being more intentional about your meals and making some sort of plan is likely to improve the nutritional quality of your diet—and that may be the real factor here.
Before changing the timing of your meals, consider whether it is likely to have a positive or negative impact on the quality of those meals. If the only way you’re going to be able to eat dinner at 6 pm is by stopping at the drive through for fast food on the way home from work, I don’t think that’s worth it. If, by contrast, eating dinner at 8 pm means that you have time to prepare a nice meal at home and eat it in a relaxed setting, I think the benefits far outweigh any potential metabolic risks.
By the same token, if late night eating is causing you to eat more calories than you need, the risk of unwanted weight gain may be more dangerous for your heart than the timing of your food intake.