How do foods affect my sleep?

There's no doubt that there are many of us that have trouble getting a good night's sleep. The statistics here are striking. For example, 42% of all healthy, middle-aged women in the United States report some kind of sleep trouble, including difficulty falling asleep, waking up during the night, or not feeling refreshed in the morning.

Sleep is a "mind-body" experience

There's no doubt that from a physiological standpoint that sleep is a complicated event and one that's related to many factors that cut across the "mind-body" spectrum. When we can't get to sleep because we're worried and feeling anxious, or depressed and feeling down, or confused and can't figure something out, we obviously aren't going to get to the root of our sleep trouble until we're able to work through the parts of our lives that we're feeling anxious or depressed about. At the same time, however, our nutritional status and the food we eat always influence our sleep. While we can't afford to overlook the psychological aspects, we also need to pay attention to the way we eat.

Patterns and timing make a difference

We've all heard the advice, "don't eat a big meal too close to bedtime." Although this advice sounds simple, it's actually very important and not that easy to follow. On our World's Healthiest Foods website, we've tried to emphasize the sheer joy of eating healthy food. Getting to savor the aroma, taste, and visual beauty of food is a part of what it means to be healthy. Many of us eat a meal late at night-within two hours of bedtime-precisely because we haven't made time during the day to enjoy food.

In fact, we let ourselves get so hungry that we don't really care any more about the joy of eating. We just want something in our stomach! Research shows that the timing and size of our evening meal is closely related to the timing and size of our other meals throughout the day. When we have a cup of coffee in the car on the way to work, grab a sandwich for lunch, or take care of all the household chores before getting around to dinner, we are setting ourselves up for a bad night's sleep.

Sometimes we rationalize and think that a big meal will actually help us get to sleep by exhausting our body as it tries to digest the large meal. It's tempting logic, but research evidence points in the opposite direction. A large meal does the opposite of slowing our body down. It asks our circulatory system to move more blood to our digestive tract. It asks our stomach to secrete more gastric acid. It asks our pancreas to become more active and produce digestive enzymes. It asks the smooth muscles around our intestines to become active. In short, when it comes to our physiology, a large meal does anything but relax us.

In addition, our digestive tracts are set up to work best when we are standing; lying down results in gravity pulling the "wrong way" to help foods digest. Even though the practice of napping after a meal is common, it isn't ideal from the standpoint of digestion. Sitting and resting are fine. For example, enjoying each other's company around the table after a delicious meal is a good idea. But lying down to sleep just doesn't help digestion.

It's also worth thinking about the physiological purpose of eating in regard to late-night meals. Nutrients and energy get released from food after we eat, not before. They help increase our vitality hours after the meal has been eaten; they cannot go back and compensate for a prior day's worth of activity that received no nutritional support. The time to have our largest meal is always before we need the most nutritional support, i.e., before we have the most physically demanding part of our day. Sleep is the least physically demanding part of the day, and the least logical target for release of food energy and nutrients. We tell ourselves we've had a hard day, and we're starved, but at this point, it's too late to repair any nutritional damage done. We need the nourishment before the hard day (and hopefully it will make the day less difficult). I should also mention how important it is not to go to bed actually hungry; this can interfere with sleep, usually by failing to keep the brain supplied with enough glucose (sugar).

whfoods.org