Why is sleep so crucial for weight management?

If you’re relying on diet and exercise to manage your weight, you could be missing a trick.

Getting a good night’s sleep on a regular basis can help to regulate hormones that affect appetite and increase your motivation to exercise and make healthier food choices.

Learn the connection between sleep and weight and discover how to make sleep your weight-loss superpower.

Studies show people who don’t get enough or have disrupted sleep have higher rates of obesity and higher rates of weight gain.

About 43% of Australian adults living with obesity get less than 7 hours or more than 9 hours of sleep a night, compared to 32% of adults in the healthy weight range.¹

“There is a bi-directional relationship between sleep and weight, or sleep and obesity, whereby we know that poor sleep impacts weight maintenance and promotes weight gain; and obesity and weight gain impact negatively on sleep,” says clinical professor Garun Hamilton, director of sleep medicine at Monash Health.

“For good health in general and weight management as part of that, there are 3 key factors: good nutrition, good exercise, and good sleep. And the sleep component is often the forgotten one.”

When we’re sleep deprived, our appetite hormones get thrown off, which disrupts hunger signals and may make us eat more the next day.

Sleep deprivation is also known to skew food preferences toward high-sugar, high-fat, calorie-dense foods.²

“There are studies demonstrating that appetite hormones increase when you're sleep deprived, and that food choices differ as well,” says Garun. “So, if you’re getting insufficient sleep, that leads to impaired decision-making.”

Feeling exhausted can also have a negative effect on your emotions.

“That makes stress management more difficult, enables mood swings and anxiety, and all of these things will then impact your emotional response to food,” says Garun.

Add to that the fatigue that comes with inadequate rest, and you’re less likely to be motivated to exercise or even keep up your usual levels of daily activity.

The good news is that even small improvements in sleep patterns can positively influence weight management.

Getting seven to 9 hours of good-quality sleep helps keep your appetite hormones in balance and supports emotional stability. Together, these make it easier to make healthy choices around food, exercise, and lifestyle.

“It's good sleep that helps set you up,” says Garun. “The platform of quality and consistent sleep sets you up to eat well and exercise well, have good mental health, and everything flows on from there.”

To ensure an optimum night’s sleep The Sleep Health Foundation³ recommends the following tips.

• Have a regular sleep pattern: Try to go to bed at around the same time every evening and get up at around the same time every morning.
• Most healthy adults should aim for around seven to 9 hours of good-quality sleep each night, while children and teens need more hours to support growth and development
• Banish devices from the bedroom: Smartphones are a constant distraction. Avoid using electronic screens within one hour of bedtime. Your mind needs to be in the habit of knowing that if you are in bed, you are there to sleep.
• Make your bedroom a haven: You should have a quiet, dark room with comfortable bedding and good temperature control, we should be aiming for about 18⁰C in the room when sleeping.
• Avoid stimulants: Caffeine (tea, coffee, cola) and nicotine are stimulants that can keep you awake. Alcohol may send you to sleep, but it will disrupt your sleep during the night.
• Avoid napping during the day: If a nap is absolutely necessary, limit it to about 20 minutes at least 4 hours before going to bed. Don’t fall asleep in front of the TV!

With a lack of sleep contributing to weight gain, and excess weight worsening your sleep quality, the cycle can be difficult to break.

Sleep disorders such as obstructive sleep apnoea (OSA), insomnia, snoring and restless leg syndrome are known to be far more common in overweight people.⁴

Effective treatment of sleep disorders can improve weight management and your good health overall. If you are having persistent trouble sleeping, or are waking unrefreshed, see your doctor for more advice.