When it comes to weight loss, most people recognize the importance of proper nutrition and regular exercise. However, one factor that is often overlooked is sleep.
Unfortunately, many fail to get enough sleep per night, which can significantly impede weight loss progress.
This article will review several scientific studies to highlight the considerable impact that sleep can have on weight loss.
Table of Contents
The Need For Sleep
While sleep is still a relative mystery, science has uncovered the importance of sleep on several crucial functions.
We need to sleep every night for a great deal of processing, strengthening, and restoration to take place.
Sleep is essential for maintaining brain health and function. Each day, our brains are highly active and must take in a vast amount of information.
Sleep allows the brain to process and store information and memories.
However, the need for sleep extends further than just the nervous system.
During the day, the body is subject to many stresses and strains. As a result, it requires a period of rest in order to recover and re-energize fully.
Therefore, to ensure that good health and function are maintained, sleep must be prioritized.
While sleep need varies from person-to-person, six to eight hours per night is the general recommendation for adults.
Consistently sleeping for less than this can lead to sleep deprivation, which can have an adverse effect on the body.
What Causes Weight Loss?
Despite the numerous weight-loss theories and beliefs, there is only one real cause of weight loss – a calorie deficit.
A calorie deficit is where the body does not have access to enough energy to maintain normal function.
Creating this calorie deficit forces the body to find energy from another source. As a result, the body primarily breaks down stored body fat in order to provide itself with energy.
Providing that this deficit is maintained for a prolonged period, a significant amount of body fat will be burned. Consequently, total body weight will also reduce.
There are two main ways of creating this calorie deficit.
The first method is to simply reduce the total number of calories consumed through food and drink.
Alternatively, calories can be expended by increasing the amount or the intensity of exercise.
Studies on weight loss have shown that a combination of calorie restriction and exercise yields the most significant weight loss results (1).
How Better Sleep Can Improve Weight Loss
Considering that a calorie deficit is the cause of weight loss, how can sleep possibly influence body composition?
There have been many studies conducted on sleep and its impact on the body. Many studies have concluded that poor sleep can significantly influence body weight and lead to obesity (2).
In this section, we will highlight several ways in which sleep significantly influences weight loss.
1. Reduces Calorie Consumption
Research has indicated that individuals who consistently get inadequate sleep tend to overconsume calories.
One particular study assessed the impact of four and eight hours of sleep on calorie consumption. When compared to eight hours, it was concluded that participants consumed 559 more calories on four hours of sleep (3).
There may be several reasons to explain this difference in calorie intake. However, one explanation is that simply being awake for longer increases the chances of consuming more.
In addition to this, other studies have suggested that poor sleep may lead to an increase in portion sizes (4). Consuming more substantial portions equates to higher calorie intake.
This is hugely significant when we consider the role of calories and weight loss.
Consuming too many will place an individual in a calorie surplus rather than a deficit. The excess calories (or energy) will be stored as body fat, thus increasing total body weight.
Furthermore, poor sleep will also impede the efforts of those who are attempting to create a calorie deficit.
2. Maintains Basal Metabolic Rate
Basal metabolic rate (or BMR) refers to the number of calories the body will burn at rest.
Studies on sleep deprivation have concluded that poor sleep can reduce basal metabolic rate.
One study involved keeping participants awake for twenty-four hours. At the end of this period, their BMR was recorded and compared to a typical night’s rest. Incredibly, results indicated that participant’s metabolic rates were reduced by 20% (5).
Once again, this is significant for those who are attempting to establish a calorie deficit. Reducing energy expenditure may make it much more challenging to create a deficit.
Good sleep may help to maintain basal metabolic rate and energy expenditure, thus facilitating a calorie deficit.
However, it must be noted that other studies on the matter have found no difference in metabolism (6). More research needs to be conducted on the subject to confirm findings.
3. Manages Appetite And Cravings
Scientific studies have suggested that those who have sleep issues have a greater appetite and an increased risk of obesity (7).
It appears that sleep has an impact on two critical hormones known as ghrelin and leptin. These hormones play a crucial role in regulating feelings of hunger.
Leptin is known to reduce feelings of hunger and signal fullness, whereas ghrelin contributes to feelings of hunger.
When sleep is suboptimal, it appears that ghrelin production increases while leptin reduces. Therefore, with less sleep, feelings of hunger and appetite may increase dramatically.
One study on short-duration sleeping found ghrelin levels to increase by 14.9%, while leptin levels decreased by 15.5% (8).
Another hormone, known as cortisol, can have a substantial impact on appetite. Inadequate sleep may also elevate levels of cortisol within the body (9).
Having a larger appetite may lead to an overconsumption of calories, thus hampering weight loss attempts.
4. Allows For Better Food Choices
One of the most evident effects of lack of sleep is poor mental clarity and decision making.
Research suggests that sleep deprivation negatively impacts the frontal lobe of the brain. It is this section of the brain that is responsible for decision making and self-control (10).
Moreover, while being sleep-deprived, it appears that the brain’s reward center is more active when eating food (11).
Finally, poor sleep can increase the chances of selecting high-calorie, high-carb, and high-fat foods (12).
Therefore, getting a good night’s sleep may help us to select nutritious foods and eat an appropriate number of calories.
5. Enhances Physical Performance
As highlighted, restricting calorie intake is not the only method for bringing about weight loss. Increasing activity levels or exercise intensity can lead to a significant calorie burn.
Poor sleep has been found to increase fatigue and reduce the time taken to becoming tired during exercise (13).
This can have a direct impact on our motivation levels and exercise intensity.
One specific study found that sleep-deprived men exercise less frequently and at a reduced intensity (14).
On the other hand, there is an array of evidence to suggest that proper sleep improves athletic performance (15).
Therefore, improving sleep quality may lead to a higher intensity of exercise and enhance calorie burn, thus, facilitating weight loss.
Tips For Improving Sleep
1. Establish Routine
The human body runs in cycles and routines. Therefore, for those who struggle to sleep, setting a waking time and bedtime can be extremely helpful.
While results may not be immediate, once a routine has been established, sleep may significantly improve.
2. Create A Restful Environment
Generally speaking, dark, quiet, and cool rooms tend to make it easier to fall asleep.
Using blackout blinds, wearing an eye mask and earplugs, and leaving a window open may all help to improve sleep.
3. Increase Activity Levels
By exercising more frequently or with higher intensity, we may increase feelings of fatigue and tiredness. As a result, sleep duration and quality may be increased.
Furthermore, there are many other benefits associated with increasing activity levels, including changes in body composition.
4. Avoid Stimulants And Alcohol
Substances such as caffeine and nicotine stimulate our body’s nervous system and increase alertness. Therefore, consuming stimulants can hamper our attempts to fall asleep.
Be aware that many stimulants stay in our system for a prolonged period. Therefore, some recommend avoiding consuming stimulants as long as six hours before bedtime.
Although alcohol can make us feel sleepy, it may negatively impact our sleep quality. Therefore, avoiding alcohol may also facilitate better sleep.
5. Ditch The Electronics
The majority of electronic devices such as TVs, smartphones, and laptops emit artificial blue light. This light has been found to suppress the release of a hormone known as melatonin.
This hormone regulates the sleep-wake cycle. Therefore, using electronics late at night may cause us to feel more awake, thus, making it more challenging to fall asleep.
Sleep And Weight Loss – Takeaway
Sleep is a fundamental process required to maintain good health and wellbeing. Failing to get enough of it can lead to a host of issues and may contribute towards weight gain.
Conversely, sleeping well has the potential to facilitate weight loss. Research suggests that good sleep can reduce calorie intake, improve metabolism, and lead to better food choices.
All of these can significantly contribute to creating the calorie deficit required to bring about weight loss.