Does my sleep affect what I eat?

We all know that feeling. Waking up sleep  deprived and reaching for a caffeinated beverage, sugary snack or a carb  hit to make it through the day. But just how much does our sleep shape  what we eat and vice versa?

There are actually several theories about how and why sleep length and quality can influence what and how much you eat.

Some are psychological theories; that we  seek reward and comfort from food when we feel poorly as we do after an  interrupted night’s sleep. Or that sleep deprivation means there are  simply more hours in the day to consume extra food and drink. Or that  our taste perceptions change and we seek out hyper palatable foods for a  quick energy hit. There have been randomised trials showing that after sleep restriction our brain reward regions light up on functional MRI's at being shown unhealthy foods.

There is also evidence that sleep length and quality influences key hormones that are important to dietary intake. Leptin, for example, reduces appetite, regulates energy intake and can influence weight. Ghrelin on the other hand, increases appetite, hunger and our desire for hyper palatable foods.

Poor sleep can mess with the balance of these hormones – leptin decreases and ghrelin increases.  This results in us feeling more hungry throughout the day, and less  full from our meals. This hormonal imbalance resulting from poor sleep  can also influence our energy expenditure. For example, we may be less  inclined to be physically active after a bad night’s sleep. But because  hormonal factors like how much fat tissue you carry can influence this  balance and our eating behaviors, it is not a straight forward  relationship.  That’s why we see health behaviors like sleep, physical  activity, nutrition and substance use cluster; they are so intricately  linked.

What is good sleep?

Sleep length and quality can determine a  good sleep. Good quality sleep is that which makes us wake up feeling  well rested, replenished and refreshed. The Sleep Foundation has recommendations for different age groups regarding sleep length.

Just like poor quality sleep can affect  dietary choices, good sleep can promote better food choices. Good  quality sleep means you may be less likely to experience those  physiological and psychological barriers that can lead to us seeking out  hyper palatable foods. There is also some evidence that those who sleep better report higher self efficacy (self belief)  that drives better nutrition and lifestyle behaviors. You can  understand why this might be the case as you may be more likely to meal  plan, cook home made meals and the like if you feel replenished after a  good night’s sleep.