Does Sleep Affect Weight Loss?

When it comes to weight loss, your diet and exercise are usually thought of as the two main key factors that will achieve results. However, sleep is an often neglected lifestyle factor that also plays an important role. 

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. Typically, the goal for weight loss is usually to decrease body fat while retaining as much muscle mass as possible. Not obtaining the right amount of sleep can determine how much fat is lost as well as how much muscle mass you retain while on a calorie restricted diet. 

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You may be wondering how shorter sleep is associated with higher body weight. There are several factors such as 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. 

Essentially, 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. So getting a good night’s rest should be prioritized.

Aside from our appetite hormones, 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 (six nights of only four hours of sleep) when compared to people who had good sleep (six nights of nine hours sleep). Lack of sleep can lead to poor decision making which can affect judgment and decision making. This can lead up to 500+ calories a day, solely because we are more likely to have intense cravings for junk foods, high fat, and high sugar foods. 

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. Lack of sleep can also lead to an increase in blood sugar, increased insulin resistance, and our ability to process carbohydrates. 

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What this means for you

Getting adequate, quality sleep is an important part of a healthy weight loss plan. Most importantly, research has proved it. Remember that health is a lifelong journey that includes not only healthy habits but also having a healthy relationship with your body.