Sleep and weight, what’s the connection?

Sleep can have a profound effect on our overall health and wellbeing for both better and worse. Yet many of us don’t sleep enough or struggle to sleep well and this is largely a product of the environments we live and work in, often compounded by our various life stressors. But aside from the obvious and well-known downsides, poor sleep may also be inhibiting our ability to maintain a healthy weight. 

It has been well established that our ability to manipulate our weight is multifaceted...yes ultimately it doesn't come down to energy balance (how much energy you consume vs how much you expend) but many factors can influence both sides of energy balance, sleep being one of them. 

When it comes to weight maintenance, poor quality or inadequate sleep has been linked to disruptions in the central brain mechanisms that may lead to weight-promoting food choices, like increasing food desire (1). Insufficient sleep also has a destabilising effect on the hormones that govern our hunger and satiety. Not sleeping enough is associated with a decrease in the satiety hormone leptin, an increase in the hunger-stimulating hormone ghrelin, and as a result of all these factors, there’s an overall increase in appetite (2). This is particularly the case for highly palatable and energy-dense food known to promote weight gain. It is often the high-fat, simple carbohydrate foods that provide quick energy to the body that we crave when we’re tired or worn down - It’s a feeling you’re likely to know well if you've ever hit that 3 pm slump after a bad night's sleep. 

Although research tells us that extended periods of insufficient sleep may increase energy expenditure from extended periods of wakefulness, the increased food intake overcompensates for any extra energy lost (2). Beyond this, chronic lack of sleep is likely to reduce participation in planned physical activity, due to the individual simply being too tired to exercise. This not only disrupts weight-management efforts but has a flow-on effect on overall health. 

All these mechanisms are of course the body's way of compensating. Adapting feeding behaviours during times of sleep loss is a physiological response that ultimately provides the body with the energy it needs to sustain the extended hours of wakefulness (2). The problem is, we live in an environment of abundance and excess. We have access to energy-dense foods and modern conveniences that reduce overall physical activity and increase energy intake...this can all add up to weight gain when bad sleep is chronic. 

But it doesn’t end there… there’s some emerging research that suggests poor sleep and resulting eating patterns may negatively influence the gut microbiome. This in turn can harm the metabolism and contribute to the development of metabolic diseases (3). What all this tells us is that sleep is abundantly important when it comes to weight management. Although poor sleep doesn’t directly cause weight gain, it is linked to an increase in total energy intake throughout the day, and when chronic, contributes to overall weight gain. 

So how much should we be sleeping? 

As we grow up we certainly don't need as much sleep as those growth spurt years, but many people tend to underestimate how much sleep they really need to function properly and thrive. The average adult should be getting no less than 7 hours of sleep with ideally 8-9 hours per night. But it is not only the length of time we sleep that’s important, it is also the quality of sleep that counts. Consistent, uninterrupted sleep is a hallmark of good health and there are certain habits that we can implement to make sure that we’re giving ourselves the best shot at good sleep. 

While this is by no means an exhaustive list, these 5 habits can help promote healthy sleep:

1. Keep a sleep schedule

Be consistent with your bedtime and waking hours even on weekends, so your sleep-wake cycle remains steady.

2. Avoid eating and drinking late at night

It’s best to limit your last meal or snack to 2 hours before bed to allow proper digestion to take place. Limiting drinking before bed also ensures you aren’t disrupted throughout the night.

3. Keep a good sleep environment

Your bedroom should be conducive to rest so there should be nothing distracting, particularly light-emitting devices such as TVs, phones, and computers. Artificial light is known to disrupt melatonin production and can delay sleep onset. 

4. Schedule in wind-down time

As mentioned above, our devices can disrupt sleep onset as can anything overly stimulating like loud music, commotion, or lively conversation. Scheduling 15-20 minutes of wind-down time before going to bed, or even reading for a few minutes under a dim light can help induce sleep. 

5. Maintain healthy habits

Daily movement, a well-balanced diet, and appropriate sunlight exposure are vital in regulating daily sleep patterns and should form part of your daily routine. Your time spent awake often reflects how your time is spent asleep so view this routine as a whole. 

If you have trouble sleeping well, it’s certainly worth investing time into researching more about ‘sleep hygiene’. Many things beyond what’s listed here can aid good sleep but it’s best to focus on small changes one at a time to avoid overwhelm. Even starting just with these can improve your sleep quality and ultimately help long-term weight maintenance and overall good health.

References

1. Greer, S. M., Goldstein, A. N., & Walker, M. P. (2013). The impact of sleep deprivation on food desire in the human brain. Nature Communications, 4, 2259.

2. Markwald, R. R., Melanson, E. L., Smith, M. R., Higgins, J., Perreault, L., Eckel, R. H., & Wright, K. P. (2013). Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain. Proceedings of the National Academy of Sciences of the United States of America, 110(14), 5695–5700.

3. Parkar, S. G., Kalsbeek, A., & Cheeseman, J. F. (2019). Potential Role for the Gut Microbiota in Modulating Host Circadian Rhythms and Metabolic Health. Microorganisms, 7(2), E41.

4. Center for Disease Control and Prevention (2016, July 15) Sleep and sleep disorders. https://www.cdc.gov/sleep/index.html