Why Sleep is So Important for Losing Weight

The Often-Neglected Factor in Weight Loss

When it comes to weight loss, diet and exercise are often the two key factors that come to mind. However, sleep is an important lifestyle factor that is often overlooked. The recommended sleep duration for adults is seven to nine hours a night, but many people tend to sleep for less than this. Research has shown that sleeping less than the recommended amount is linked to having greater body fat, increased risk of obesity, and can also influence how easily you lose weight on a calorie-controlled diet.

How Sleep Affects Weight Loss

Typically, the goal for weight loss is to decrease body fat while retaining as much muscle mass as possible. Not getting the correct amount of sleep can determine how much fat is lost and how much muscle mass you retain while on a calorie-restricted diet. One study found that sleeping 5.5 hours each night over a two-week period while on a calorie-restricted diet resulted in less fat loss compared to sleeping 8.5 hours each night. However, it also resulted in a greater loss of fat-free mass, including muscle.

Changes in Metabolism, Appetite, and Sleep

There are several reasons why shorter sleep may be associated with higher body weight and affect weight loss. These include changes in metabolism, appetite, and food selection.

Sleep influences two important appetite hormones in our body – leptin and ghrelin. Leptin is a hormone that decreases appetite, so when leptin levels are high, we usually feel fuller. On the other hand, ghrelin is a hormone that can stimulate appetite and is often referred to as the “hunger hormone” because it’s thought to be responsible for the feeling of hunger. One study found that sleep restriction increases levels of ghrelin and decreases leptin. Another study, which included a sample of 1,024 adults, also found that short sleep was associated with higher levels of ghrelin and lower levels of leptin.

This combination could increase a person’s appetite, making calorie-restriction more difficult to adhere to, and may make a person more likely to overeat. Consequently, increased food intake due to changes in appetite hormones may result in weight gain. This means that, in the long term, sleep deprivation may lead to weight gain due to these changes in appetite.

The Impact of Sleep on Food Selection

Reduced sleep has also been shown to impact on food selection and the way the brain perceives food. Researchers have found that the areas of the brain responsible for reward are more active in response to food after sleep loss compared to people who had good sleep. This could possibly explain why sleep-deprived people snack more often and tend to choose carbohydrate-rich foods and sweet-tasting snacks compared to those who get enough sleep.

The Relationship Between Sleep and Metabolism

Sleep duration also influences metabolism, particularly glucose (sugar) metabolism. When food is eaten, our bodies release insulin, a hormone that helps to process the glucose in our blood. However, sleep loss can impair our bodies’ response to insulin, reducing its ability to uptake glucose. We may be able to recover from the occasional night of sleep loss, but in the long term, this could lead to health conditions such as obesity and type 2 diabetes.

How Exercise Can Help Counteract the Effects of Poor Sleep

Physical activity may show promise as a countermeasure against the detrimental impact of poor sleep. Exercise has a positive impact on appetite, by reducing ghrelin levels and increasing levels of peptide YY, a hormone that is released from the gut and is associated with the feeling of being satisfied and full. After exercise, people tend to eat less, particularly when the energy expended by exercise is taken into account. However, it’s unknown if this still remains in the context of sleep restriction.

Research has also shown that exercise training may protect against the metabolic impairments that result from a lack of sleep, by improving the body’s response to insulin, leading to improved glucose control. We have also shown the potential benefits of just a single session of exercise on glucose metabolism after sleep restriction. While this shows promise, studies are yet to determine the role of long-term physical activity in people with poor sleep.

Conclusion

It’s clear that sleep is important for losing weight. A lack of sleep can increase appetite by changing hormones, makes us more likely to eat unhealthy foods, and influences how body fat is lost while counting our calories. Sleep should therefore be considered as an essential alongside diet and physical activity as part of a healthy lifestyle.

FAQs

Q: How much sleep do I need to lose weight?
A: The recommended sleep duration for adults is seven to nine hours a night.

Q: Can sleep deprivation affect my appetite?
A: Yes, sleep deprivation can increase appetite by changing hormones and making you more likely to eat unhealthy foods.

Q: Does sleep affect my metabolism?
A: Yes, sleep duration also influences metabolism, particularly glucose (sugar) metabolism. Sleep loss can impair our bodies’ response to insulin, reducing its ability to uptake glucose.

Q: Can exercise help counteract the effects of poor sleep?
A: Yes, physical activity may show promise as a countermeasure against the detrimental impact of poor sleep. Exercise has a positive impact on appetite and can improve glucose control.