When individuals lose water as they sleep, they experience insensible water loss, which is a loss of water through physiological processes such as breathing, sweating, and excretion.
Health experts say that water loss from breathing and sweating alone can account for up to 83% of weight loss during sleep.
The amount of water that individuals lose during the night will vary because not everyone has the same metabolic rate.
Can sleep disruption impact weight loss?
Sleep disruption can affect many biological processes, including hunger.
One 2017 reviewTrusted Source reported that people who experienced altered sleeping patterns had generally larger appetites and consumed more calorie-dense meals than those who did not.
This finding suggests changing sleep times could have consequences on a person’s weight management.
A 2016 study found the body mass index of nursing professionals increased when they switched from day to night shifts.
Additionally, a lack of sleep can also increase the riskTrusted Source of metabolic syndrome, where a cluster of risk factors can occur simultaneously. When several of these risk factors occur, the likelihood of developing cardiovascular disease, stroke, and diabetes increases.
These risk factors includeTrusted Source:
excess fat around the abdominal area
low levels of high-density lipoprotein, or “good” cholesterol
high levels of triglycerides
high blood sugar
high blood pressure
To limit the occurrence of these risk factors, a person can try to maintain a moderate weight. It is also important that they get sufficient sleep and follow a nutritious diet to prevent the onset of more serious conditions such as heart disease.
Can improving sleep health promote weight loss?
When a person improves their sleep health, they are more likely to maintain a moderate weight.
For example, a 2021 studyTrusted Source states that people with sleep apnoea lost more body weight and fat over a 12-month period when they experienced better sleep.
Researchers have also linkedTrusted Source shorter sleeping intervals to hedonic eating. When a person is eating hedonically, they are eating more for pleasure. Over time, this behavior could result in more non-nutritious food choices and a higher calorie intake.
Conversely, when individuals sleep for longer, they are less likely to eat hedonically and crave non-nutritious pleasure foods.
Additionally, a 2021 study found hedonic hunger decreased in university students when they experienced better sleep quality. This suggests that people consume fewer calories after a good night’s sleep and make more nutritious food choices because they do not have the urge to consume food for pleasure.
Improving sleep hygiene to support weight loss
Sleep hygiene is a term that describes a healthy sleep routine.
There are several actions a person can take to improve their sleep hygiene, which includeTrusted Source:
Introducing consistency: Going to bed at the same time each night prepares the body for sleep. Waking up at the same time each day means a person is tired enough to fall asleep when bedtime approaches. People should aim for 7–8 hours of sleep each day.
Creating a healthy sleep environment: A dark bedroom will help a person feel more ready for sleep. Try to turn off all TVs and computers before going to bed. People can also go to sleep quicker if they keep laptops or cell phones out of the bedroom.
Avoiding large meals before bedtime: A person is unlikely to feel tired when their body is digesting a substantial meal. Additionally, when people consume caffeinated drinks, they are more alert and awake. Therefore, they should avoid consuming these before bedtime.
Staying active: When a person is physically active during the day, they feel more tired, as their body is using more energy.