Health & Wellbeing

How what you eat affects the depth of your slumber

How what you eat affects the depth of your slumber
A new study has found that what you eat can affect the quality of your sleep
A new study has found that what you eat can affect the quality of your sleep
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A new study has found that what you eat can affect the quality of your sleep
A new study has found that what you eat can affect the quality of your sleep

We know how diet can affect general health, but what effect does it have on sleep specifically? A new study has found that what we eat can directly affect our sleep quality.

Good nutrition and good sleep are fundamental to health; both enable our bodies to stay healthy and fight diseases. While they have an important relationship, it’s a complicated one involving multiple interconnected body systems. The bottom line is that recognizing the link between sleep and nutrition and optimizing both is important for ensuring good health.

Previous studies have examined how what we eat affects our sleep. However, few studies have considered how different diets directly affect sleep quality. Now, a new study by researchers at Uppsala University in Sweden has examined whether and how different diets impact sleep.

“Both poor diet and poor sleep increase the risk of several public health conditions,” said Jonathan Cedernaes, corresponding author of the study. “As what we eat is so important for our health, we thought it would be interesting to investigate whether some of the health effects of different diets could involve changes to our sleep.”

The researchers recruited 15 healthy male participants and randomly fed them either a high-fat/high-sugar (HFHS) or a low-fat/low-sugar (LFLS) diet. They weren’t told in advance what kind of diet they’d be eating. Participants were instructed to keep to their usual sleeping habits – seven to nine hours a night – and asked to record their daily sleep in a sleep diary.

At the end of each dietary intervention, the participants’ sleep was monitored in a sleep laboratory. The researchers found that while participants slept for the same amount of time regardless of the diet they ate, there were differences in sleep quality between the two groups.

“Specifically, we looked at slow-wave activity, a measure that can reflect how restorative deep sleep is,” said Cedernaes. “Intriguingly, we saw that deep sleep exhibited less slow-wave activity when the participants had eaten junk food, compared with consumption of healthier food. This effect also lasted into a second night, once we had switched the participants to an identical diet. Essentially, the unhealthy diet resulted in shallower deep sleep.”

Slow-wave sleep, also known as deep sleep, is thought to play an important role in restoring the brain and the consolidation of memories. It consists of stage 3 non-rapid eye movement (NREM) sleep, usually lasts between 70 and 90 minutes, and occurs during the first hours of the night.

The researchers noted that the changes in sleep quality related to diet are similar to those seen with aging and insomnia. But they currently don’t know how long-lasting the effects of eating an unhealthier diet may be and can’t pin it on a particular substance in the diet. They’re urging further research to investigate.

“It would also be interesting to conduct functional tests, for example to see whether memory function can be affected,” Cedernaes said. “This is regulated to a large extent by sleep. And it would be equally interesting to understand how long-lasting the observed effects may be. Currently, we do not know which substances in the unhealthier diet worsened the depth of deep sleep … It would be interesting to investigate whether there is a particular molecular factor that plays a greater role.”

The study was published in the journal Obesity.

Source: Uppsala University via EurekAlert!

Brian M
The interesting thing is in just about every experiment you read about involving this sort of dietary comparison, you know what the result will be before you reach the conclusion at the end.

Unfortunately the bad stuff (for you) still tastes great!
like jack lalanne said, "if it tastes good, spit it out! it's not good for you."
Nice article Paul. Unfortunately this is old news codified by subjective recall diaries. And many of us have worked on improving our sleep and diet. I've read the comments - these experiments do have an endpoint that we wish we were certain about - and this study does nothing definitive in that respect. Yes, they reached their conclusion at the end - the subjects slept the same number of hours and had differing brain wave activity in their deep sleep. @BrianM -- Now they can propose a study to evaluate the long term effects of the brain wave activity and risk of dementia or other medical sequealae since we only have conjecture as to the results. See how Scientific Method works?

For those who can't figure the taste & good for you equation: Try a few weeks of zero sugar. No honey, no artificial sweeteners, no granulated sugar of any type. After two weeks of "Oh so bland" food, then start back on no sugar added food cooked fresh. Sauteed vegetables in olive oil, grilled vegetables and meet without a sugar infused glaze, etc. And after that 4 weeks of deprivation - decide what you want to do - go back to a diet that keeps you alive while contributing to health issues, or go to a diet that actually tastes good without all the excess carcinogen of sugars once you have your taste buds back!
Just as Brian M observed -- that we know what the results will be -- one has to suspect that the "researchers" were dedicated to proving that "health" foods are better than those currently disfavored. Of course, knowing a bit of the history of nutrition, I recall that when muesli was part of a diet recommended in Europe, doctors called the creator (a doctor) a quack and said that eating raw fruit was dangerous.