Have you ever considered your diet to be connected to your sleep? What kind of food choices do you make when you are tired vs the times you are well-rested? Not often a topic we immediately link together, but there is increasing evidence on the relationship between the foods we eat and our sleep. This article will explore sleep and diet, and the cool areas of nutrition research that have enhanced our understandings – from hormones to hunger, and tryptophan to cherries, let’s take a quick dive into the research on the relationship between diet and our sleep.
Sleep and our hormones
Sleep regulation is complex, and quantity is not the same as quality. The circadian rhythm is also known as our internal alarm clock, and is regulated by many diffeent hormones. Two such hormones are involved in the hunger response. Studies have shown that the hormones ghrelin (the hunger hormone) increases, and leptin (the fullness hormone) decreases, when you do not get enough sleep. In fact, a large study found that individuals who were sleep deprived ate on average 400 extra calories per day compared to those who got enough sleep.
So, getting adequate sleep may help control your appetite, and total daily calories, by regulating your hormones. It is also evident that if you are not sleeping, you are more likely to eat later into the night, not allowing your body the opportunity for your body fat stores to be used.
And since food type and timing, actions that we have control over, also regulate the balance of these hunger hormones – you can start to see how you can influence this relationship between your diet, hormones, and sleep.
What foods can affect our sleep?
A randomized control trial is considered the gold standard in research. And one such 2016 study found that diets high in fibre and lower in saturated fat predicted better quality of sleep. Similarly, diets lower in fibre, and higher in saturated fat and sugar is associated with lighter, less restorative sleep with more arousals.
One diet strategy that is also implicated in sleep is the Mediterranean diet. This diet is high in vegetables, fruits, whole grains, beans, lentils, nuts and seeds, olive oil, and seafood. Since sleep duration and quality are also predictors of risk for heart disease, one research study investigated if there was a link between following this well-known “heart-healthy” eating pattern and sleep. Their findings? Highly suggestive that a Mediterranean-style diet is associated with adequate sleep duration, fewer symptoms of insomnia, and less likely to have insomnia accompanied by a short sleep.
Taken together, the Mediterranean dietary pattern is consistent with the findings from the randomized control trial on high fibre, low saturated fat, and low sugar in the management of better sleep quality and quantity.
Fun facts and promising research from smaller studies
- Alcohol may help to induce sleep, but it alters the sleep pattern and is associated with disrupted, poor quality sleep.
- Daily caffeine intake is strongly associated with altered sleep onset, duration, and perceived quality.
- Adequate protein may enhance sleep, potentially through tryptophan.
- Certain types of cherries may increase melatonin (the sleep hormone) in the urine, total sleep time, and sleep quality. Other sleep benefits were also observed. This positive impact, if confirmed, is likely due to the high concentration of melatonin in cherries, and their high levels of antioxidants.
- Kiwifruit has also been implicated in improving sleep. One four-week study in adults with sleep problems found that two kiwifruits per day one hour before bedtime significantly increased sleep quantity and quality, potentially due to it’s unusually high content of serotonin, folate, and high antioxidant capacity.
There is much more research in this area, beyond the scope of this month’s article. But it’s important to note that some of these studies are small, and limited in their design and application. Further research is needed in larger, different populations to identify potential roles for specific nutrients.
Summary
Sleep and diet are connected. The Mediterranean dietary pattern appears to be one way to help improve sleep and ensuring proper sleep appear5s to encourage food choice and quantity. One of the challenges in nutrition research and sleep is determining whether it is sleep affecting diet, or diet affecting sleep. But the relationship is evidenced through emerging research such as those discussed here and is becoming increasingly clear that it’s likely a combination of both.
I invite you to reflect on this important relationship between diet and sleep – how it relates to your current patterns, your goals, and finally – ways in how you can improve one or the other.
Everything in nutrition and lifestyle is connected! Stay happy, healthy, and motivated!
Choose a balanced lifestyle strategy that works for you. Everyone’s goals are unique, as are their journeys!
Dan Neuman
Registered Dietitian