Welcome to week 8 from the Lifestyle Medicine team.
We’ve talked with a lot of people about their issues with losing weight. What we’ve found is that most people don’t realise how important getting enough sleep is to supporting their ability to lose weight. We’re going to share with you some of the reasons why sleep is so important to help you lose weight, and share some tips about how you can improve the quality of your sleep, if you’re experiencing sleep difficulties.
If you're regularly suffering from poor sleep and trying to lose weight you need to take action. We recommend that you prioritise improving your sleep to support your weight loss goals. You might be wondering, what has sleep got to do with weight loss? Your appetite and how much you eat is predominantly controlled by two hormones - Ghrelin and Leptin. Leptin tells your body when you're full and Ghrelin tells your body when you're hungry. Leptin and Ghrelin levels are directly affected by how much sleep you get and low levels of sleep is likely to increase your appetite (1).
Ideally, you should aim to sleep between 7 and 9 hours a night. If you sleep less than this your body will produce more Ghrelin - the hunger stimulating hormone - leading to you feeling more hungry the next day. At the same time, Leptin levels are reduced so you'll feel less full. Low levels of sleep are known to be common in the UK, and this is thought to be a factor in the growing issue of high BMIs across the country. There’s a greater chance that you'll struggle to control how much you eat or snack after a poor night’s sleep.
We know that not getting enough sleep also affects your food choices - when you have poor sleep you're more likely to be tempted to eat high fat unhealthy foods. You can probably relate to feeling tired or sleep deprived and craving or choosing foods that are high in calories and carbohydrates to try and boost your energy levels (2). These tend to be foods like bread, pasta, cheese, chocolate, crisps, or pastries.
As we talked about in the good food week, these foods tend to negatively affect your blood sugar balance and energy levels when you eat them, and can make it hard for you to lose weight as well as contribute to you gaining weight.
Research has found that you're likely to eat as many as an extra 300 calories a day if you experience four hours or less sleep a night for five nights in a row (3). If insomnia or difficulty with sleep continues for longer than this, your risk of developing type 2 diabetes also increases(4). When you're looking to lose weight and only sleeping for short periods there is also a risk that your body composition will be affected because you’re more likely to lose muscle mass rather than fat tissue (5).
Top Tips from the Lifestyle Medicine Team to Improve Your Sleep
We recommend that you create new morning and bedtime habits to optimise your circadian rhythm. Morning - aim to get out in the natural morning light for five minutes or more each day. This can help to regulate your melatonin levels - a hormone that stimulates sleep. If you're working indoors – sit by a window to maximise how much natural light you get in the daytime. Block blue light in the evening and night - Blue light suppresses your sleep hormone melatonin (6), which can reduce how easily you fall asleep, your sleep quality and how long you stay asleep.
Use blue blocking light bulbs or wear blue light blocking glasses, use blue light blocking screen filters or apps, or avoid screen time later in the day to reduce your blue light exposure. Aim to get to bed before midnight . Anecdotally, it is thought that your sleep quality is better if you get some sleep before midnight (7,8). Aim for an hour or two. This is all to do with how your body responds to the changing light levels in the evening. You can also download a copy of our Top Tips for Sleep Guide.
