We all know the importance of a good night's sleep. Glowy skin. Swathes of energy. Enhanced mood. But two new studies have also confirmed its importance when it comes to any healthy, sustainable weight loss goals you may have.
Indeed, while the contents of your plate may be on point from a nutritional perspective and you're smashing PBs in the gym, all that effort will prove fruitless if your snooze time is poor quality. That's according to research showing how a disrupted circadian rhythm plays a key role in the growth of fat cells.
First things first, the circadian rhythm is the natural cycle that the body goes through during a 24-hour period and controls its sleep-wake pattern. Studies have shown that ensuring it functions optimally is crucial for everything from cardiovascular health to brain function.
What's more, as the new findings confirm, the circadian rhythm can also be responsible for weight management. One of the new studies, conducted in mice, found that disturbing it triggered a mechanism which saw a boost in fat cells and insulin production. This meant that even though they were eating the same healthy diet, the metabolism shift lead to weight gain.
The second study showed how fat cell precursors commit to becoming fat cells during the rest period of mice. 'The decision to become a fat cell happens rapidly over four hours. It is like a switch,' said Dr Mary Teruel, an associate professor of biochemistry and senior author of both studies. 'It only happens at a certain time of day.'
As such, both sets of findings indicate that a disrupted circadian rhythm - due to stress and other factors - can lead to weight gain. 'A lot of forces are working against a healthy metabolism when we are out of circadian rhythm,' explained Dr Teruel. 'The more we understand, the more likely we will be able to do something about it.' Her team are now looking into the possibility of drugs that can help reset circadian rhythms in people with obesity.
Of course, there are other ways not enough sleep can affect your weight too. A lack of Zzz causes levels of leptin - the hormone that tells you to stop eating - to decline, and levels of the 'hunger' hormone ghrelin to increase. Additionally, research has found that when you are sleep deprived you make poorer food choices, with another study showing that high-calorie options become much more tempting (we can concur).
So, just as a reminder, The Sleep Charity recommends adults get around eight hours sleep per night. It is important to build a good bedtime routine, which includes hitting the hay at the same time each evening and avoiding phone, laptop and TV screens close to lights out. It also doesn't hurt to invest in the best pillow for your neck and best mattress for your back to ensure you doze soundly all night long...
Lauren is a lifestyle journalist with digital and magazine experience. Find her covering all aspects of wellness - from fitness, nutrition and mental health, to beauty and travel. Morning HIIT, a lunchtime oat latte and evenings ensconced in a hyaluronic acid-infused sheet mask are her own personal feel-good pillars.
