Sleep and Body Composition

Sleep and Body Composition

I see you scrolling. We all do it—that absent-minded late-night wandering of the mind in a bid to zone out from the day’s events. However, if you are trying to reign in your diet and are not including your sleep patterns into the equation, you need to listen up.

It’s time we stop seeing sleep as an optional extra and start looking at it as one of the most potent wellbeing tools we have- especially if you are looking to drop some unwanted kilos.

Although sleep requirements are different between individuals, the consensus is that we should be hitting in the vicinity of 7-8 hours per night. It is now well established that not sleeping enough, even just one night, is linked with changes to our body’s metabolic chemistry, which can affect our weight and wellbeing; and the research is now really homing in on what is really happening here.

Here is one very well-designed study that investigated the link between appetite regulation and sleep disruption, published in 2019.

The randomised cross over study took 24 women of BMI <25 who had no history of sleep disorders and reduced their habitual sleep by 33%- which is an amount that reflects how our sleep might be disrupted in real life.

The study reported on hunger, tiredness, cravings, sleep quality and sleep duration. They also asked participants to undertake a number of food-related tasks after the normal night (NN) sleep and Curtailed Night sleep (CN), including serving up a meal and snacks from a standardised buffet menu, and task where they participants clicked a button to ‘work’ for chocolate rewards- the more clicks, the more chocolate was rewarded.

The researchers found that participants served themselves more food (an extra 145 calories in one meal), chose higher protein and fat portions, picked higher fat snacks, ‘worked’ for longer to earn more chocolate on the food reward click task. Put simply; shorter sleep duration increased the urge to eat highly palatable foods (foods that are generally higher fat, higher sugar, higher calorie).

It is believed that inadequate sleep changes not only the types of food we feel like eating, but also affect the hormones related to hunger and our judgment on how much we need to eat in order to feel full, leading to larger portion sizes being served up after a bad night’s sleep. This is useful to understand on several levels. Firstly, knowing that if you have trouble sleeping and are trying to tor improve your food choices and lose weight, it might be useful to focus in on sleep first. And more practically speaking, if you have had a bad night’s sleep, being mindful of this likely increase in food cravings and having healthy options ready to go can help. Very practically speaking if you have had a bad night’s sleep, you might set yourself up before you get caught out and look at stevia or artificially sweetened options as a way of riding out the sweet cravings without going crazy on the real sugary options.

If you want to clean up your sleeping act, here are some hot tips for getting started:

To Improve Sleep, Each Night

  • Avoid caffeine after about 3 pm. Caffeine has a half-life of 6 hours, which means it can still be in your system and affect your sleep later at night, especially if you are sensitive to it.
  • Reduce the lights used in the evening to help cue your body that it’s time to sleep. Use dimmer lights if possible, to reduce evening light to a soft glow. 
  • Cut off screens and electronics and hour before bedtime to allow your eyes to adjust to lower light and for melatonin (the sleep hormone) to gradually rise.
  • Create a night-time routine. Include a hot drink, and warm shower and other relaxing activities and repeat them each night, so your body starts to anticipate these as cues for bed. 
  • Aim to have your last meal a few hours before sleep, but don’t go to bed hungry as this can disrupt your sleep. Contrary to common belief, carbohydrates at night-time can assist in relaxing into your bedtime routine, ensure the portion size is sensible. However, eating very late at night can interrupt our circadian rhythm, so it is essential to keep this in mind when looking at your regular mealtimes.
  • Make a habit of using a stand-alone alarm clock and keeping your phone out of reach if you have problems with mindless phone scrolling at night-time. 
  • Cooler temperatures lead to better sleep, so if you can, keep your room at lower temperatures, especially while you are trying to improve your sleep. 16- 17 degrees is a useful guide.
  • Keep a sleep journal by your bed to dump anything that is keeping you up onto the pages. This can help ease anxious minds, and help you go back to sleep if an idea is waking you up.
  • If you can’t go to sleep within 30 minutes, get up and do a bit of light reading until you begin to feel sleepy again. There is nothing worse for sleep that worrying about not getting to sleep!
  • If you usually get to bed very late, aim to bring forward sleep time by 15 minutes every night or week until you get to a reasonable bedtime. The hours of sleep before midnight are usually the best quality, so aim for no later than 10.30 pm bedtime if possible. 

These tips can take time to implement; however, the time is well worth the investment.