On Nutrition

It’s that not-so-magical time of the year when we lose an hour out of our already busy lives due to the annual transition from standard time to daylight saving time. If you’re muttering to yourself, “Really? This again?” you’re not alone. I mean, Hawaii and Arizona did away with this nonsense more than 50 years ago, so why not us?

Ironically, but perhaps not coincidentally, National Sleep Awareness Week begins March 13, just as many Americans are greeting the day a bit more bleary-eyed. But how affected you are by the time change and a lost hour of sleep may depend on whether you’re an early riser or a night owl. Research published last year in the journal Scientific Reports found that people genetically wired to be early risers only took a few days to adjust, while those whose natural state is to stay up late still showed jet lag-type symptoms a week later.

Time changes aside, it’s common to push off bedtime any time of the year because we feel like we have better or more important things to do — answering emails, tidying up, watching “just one more” episode of something. But when you’re sleep deprived, your body tries to compensate by increasing its levels of adrenaline and cortisol, and one week of mild sleep restriction increases levels of inflammation in the body, thanks to this activated stress response. Over time, regularly postponing bedtime when you have a firm morning wake-up time may increase your risk of future health problems — including heart disease, Type 2 diabetes and depression — no matter how well you might eat and regularly you might exercise.

Sleep and nutrition

Speaking of eating, it appears that how we eat may affect our sleep, and how we sleep may affect how we eat. A study published last month in the journal Nutrients looked at data from the National Health and Nutrition Examination Survey and found that people who had average- or optimal-quality diets were less likely to experience sleep disorders than people with lower-quality diets, even after accounting for other factors that could affect sleep, such as socioeconomic status, smoking status, alcohol and caffeine intake and whether someone has high blood pressure, diabetes or depression.

On the flip side, clinical sleep restriction studies have observed changes in hunger and satiety hormones, which may explain why when you haven’t been sleeping enough — or well enough — you are more likely to crave sugar and other quickly digested carbohydrates. This may feel distressing, especially if you struggle with thoughts or beliefs about “good” and “bad” foods, and that stress can amplify your food urges even more.

Adding insult to injury, when you finally hit a wall around 2 p.m. you might decide that a cookie — with a coffee — is just the pick-me-up you need. But while you may feel better in the short term, you’re setting yourself up for another night of poor sleep. Too much coffee or other sources of caffeine, especially later in the day, just doesn’t make for restful slumber. To avoid this vicious cycle, avoid caffeine for at least four to six hours before bed — some people find they need to cease caffeine by noon.


Another beverage habit that can get in the way of quality sleep is alcohol. While that nightcap has a sedating effect initially, once it wears off you may find yourself waking up right when you’re in the middle of the restorative stages of sleep. For better sleep — and general health — keep your daily intake moderate and avoid imbibing within three hours of bedtime.

What about solid food? Avoiding eating late in the evening is particularly important if you’re prone to acid reflux, but even if you’re not, doing serious digesting when you should be sleeping can make your sleep less restful. Ideally, eat dinner at least three hours before bed — especially if dinner includes spicy or acidic foods — but if you must dine late, keep it light.

If you find that when you stay up late you start to get hungry again, that may be a cue to go to bed on time. But what if you already do still need a bedtime snack, perhaps because you eat dinner early? Foods with slower digesting carbohydrates, such as milk or yogurt (if you tolerate dairy), or a slice of whole-grain toast are good choices. Research also suggests that consuming kiwi fruit, which contains serotonin, or the fruit or juice from tart Montmorency cherries, which contain melatonin, may support quality sleep.

Sleep and lifestyle

If your best time of day to exercise — whether due to preference or practicality — is in the evening, you might wonder how that affects your sleep. Research is clear that both aerobic and resistance exercises improve sleep, no matter when you do them, with one caveat — performing high-intensity exercise such as running, fast dancing or high-intensity interval training one hour or less before bedtime can make it harder to fall asleep and sleep soundly. With that in mind, making it a habit to start winding down about an hour before lights out — especially if your mind has been racing all day — can help you get a better night’s sleep.

The bottom line is that getting enough quality sleep is a profound act of self-care. Sleep needs vary from person to person, but for optimal health, the general recommendation is that adults get at least seven hours per night on a consistent schedule — in other words, sticking closely to the same bedtime and waketime. Some people feel great after seven hours while some need a solid eight, just as some people thrive with an afternoon nap while others are just not natural nappers. One more bit of food for thought: if you are consistently sleeping for more than nine hours and don’t feel rested, talk to your doctor.