Who hasn’t been sleep deprived at some point or another? Definitely as students I’m fairly certain we can all say there have been periods of time that you have stayed up late cramming for an exam or finishing off an assignment. New parents can definitely relate – sleep deprivation hits a whole new level and yet we somehow still manage to function. Though, what makes you get through the next day? Do you find yourself heading straight for the high-energy sugar laden foods? I know as a mum to a toddler and a uni student, I’ve been there, I’m still there and can say despite all my knowledge, I still find myself doing this!
Sleep deprivation can lead to an increase in calorie intake
Got a case of the 3:30-itis munchies? Or maybe it’s late night snacking you prefer? We joke, but studies are showing poor sleep habits are resulting in increased snacking. In both children and adults, studies have shown that sleep deprivation or reduced sleep hours leads to increased calorie intake, particularly snacking, often resulting in subsequent weight-gain. A 2013 study found that participants who were sleep-deprived had an increased desire for high-calorie food, with these sleep-deprived participants consuming an extra 600 calories on average. Interestingly, the desire for lower calorie foods did not change between the well-rested and sleep-deprived state. Generally, sleep studies have found those who are sleep-deprived tend to consume high-fat food, fast food, have low fruit and vegetable consumption, and snack more frequently.
Despite the link between sleep deprivation and poorer food choices being made, the actual mechanism behind why this happens is still largely unknown. The 2013 study outlined above did however find neuronal changes in the brain in the sleep deprived state. This study reported increased activity in the amygdala (the area of the brain stimulating appetite), whilst also showing decreased activity in the frontal and insular-cortex (the area of the brain that is associated with appetitive evaluation). Appetitive evaluation is when people have a desire for high-calorie foods because the brain can’t evaluate those desires or cravings in the same way it would in a well-rested person. This means that between these two specific changes in brain activity (increased amygdala activity and decreased frontal and insular-cortex activity) those who are sleep deprived have shown an increased desire for high calorie food choices.
Sleep deprivation and weight gain
Its well-known that the prevalence of obesity is continually increasing. The culprits of this weight gain are usually thought of as diet and physical activity, however it is now believed that sleep deprivation is linked to the increases in obesity rates amongst children and adolescents. These studies have shown that decreased sleep is associated with children as young as five having increases in food responsiveness, meaning if they see something yummy in front of them they’ll eat it regardless if they are hungry or not. Thus, links between shorter sleep to obesity have been made, though more longer term studies are needed to understand this issue over a longer period of time and into adulthood.
As discussed in the aforementioned 2013 study, participants who were sleep-deprived remained hungry and continued snacking, consequently eating more calories than needed. As with excessive calorie intake in even the well-rested person, this increase in nutrient-poor, high-calorie foods ultimately leads to weight gain. Often when we are fatigued, motivation for physical activity can be lacking. Combine that with excess snacking, this leads to weight gain. Continue on this cycle and it’s easy to see how the weight can creep on. Studies have shown a link between reduced sleep and weight gain, with a systematic review finding that shorter sleep durations are independently associated with increased weight. As previously mentioned, however, more studies do need to be conducted to determine mechanisms involved and causal relationships between the two.
It is thought that sleep deprivation has an impact on weight due to the effect on appetite and physical activity, with an increased Body Mass Index (BMI) being proportional to decreased sleep. While the mechanisms are unknown, we do know there are hormonal changes associated with sleep deprivation. One train of thought, which is commonly discussed in the literature, is related to the regulation of appetite hormones leptin and ghrelin. Leptin suppresses appetite and has found to be decreased in those people who are sleep deprived whilst conversely the appetite stimulant, ghrelin saw an increase. It has been found that the increase in ghrelin promoted high intake of high carbohydrate foods. Overall, researchers found that people had on average higher weights when not gaining enough sleep and if we are going to continue to battle this obesity epidemic then further studies looking into the mechanisms behind sleep restriction and weight gain need to be conducted.
Most adults require 7 – 9 hours in order to function properly the next day
The requirements for sleep change throughout the childhood years, but by about 20 years old the requirements steady and as such The National Sleep Foundation recommends that adults 18 – 64 years receive 7 – 9 hours sleep each night. Many people complain of not getting enough sleep at night usually blaming work or having a busy schedule for their inadequate sleep.
The National Sleep Foundation also provides some tips to help promote sleep each night, including the following:
- Regulate your body clock: having a sleep schedule whereby you go to bed and wake at the same time each day can help to fall asleep at night.
- Create a relaxing bedtime routine: avoid looking at anything that will increase your stress levels to rise, take a bath, read a book anything that will help you to relax.
- Avoid using technology, phones, tablets, laptops, TV and alike before bed.
- Exercise daily, even if only light exercise as this helps you to sleep more soundly but avoid exercise right before bedtime.
- Go to sleep when you are genuinely tired. If you aren’t tired and can’t fall asleep this usually ends in frustration.
- Avoid alcohol and caffeine prior to bedtime.
It is such a vicious cycle – when you’re truly tired, you tend to have more caffeine and high energy foods to help you stay awake, yet it is those foods which actually hinder your ability to fall asleep at night, not to mention are full of empty calories! Poor sleep quality has been found with diets low in vegetables and fish and high in confectionery, refined carbohydrates, sugary beverages and energy drinks, as well as in those people that skip breakfast and have irregular eating habits. This all sounds familiar doesn’t it? Having a wholesome balanced diet, incorporating the key food groups and avoiding the sugar laden empty calories is beneficial on multiple levels. It has been reported that eating the right foods and avoiding these key foods can help promote sleep. There are a few foods with reported sleep-promoting properties, with one particular food often thrown around as a sleep aid, is milk, it contains tryptophan, an amino acid needed by the body to produce serotonin, which slows nerve impulses and has been known to make one feel calm and drowsy. B vitamins are also needed for serotonin and thus gaining enough through your diet has been suggested in promoting sleep but to date studies on sleep promoting foods have been small scale and limiting. For now, the best solution is promoting a diet full of fresh fruit, vegetables, whole grains and protein.