How Can Sleep Affect Your BMI?

KCasey's picture

What are the health benefits of sleep?
    Whilst it is known that ensuring the optimum amount of sleep can help combat cancer, heart disease and improve cerebral workings, it is less known that such an activity can also help to maintain weight.


   Of all the studies into this area it has been found that those who sleep less are more likely to be overweight. Most recently the British Medical Journey studied 244 children and measured their sleep times and their Body Mass Index (BMI) to see if they could locate a correlation between the two.

The findings highlighted that children aged between three and seven who engaged in the optimum amount of sleep, for their age this constitutes eleven hours, were much less likely to be overweight than those who slept less. Another point of note is how for every extra sixty minutes a child gained in sleep time, the chances of them being overweight fell by nearly two thirds.
Other research in the past has shown similar results. For example Dr Currie‘s studies at the Warwick Medical school have shown that children who got less than the appropriate amount of sleep at 30 months of age were 45% more likely to be obese at the age of seven than their peers who slept for at least twelve hours per night.

There are many different ways in which sleep can effect weight including the release of various hormones and the effects a circadian sleep pattern, regular and established times for falling asleep and waking up, can have on the body.

Sleep’s effects on hormones

   During sleep the body naturally releases a number of hormones which have a large range of restorative effects. Some, such as Melatonin and Cortisol, act as “immune system moderators” which aim to improve health by fixing broken cells and thus staving off the risk of cancer. As these hormones are released during sleep it is important to get an optimum amount of slumber time. Similarly hormones are released in the night which can help combat weight. Leptin and Grehlin are two hormones which relate directly to this.

During sleep the body releases the hormones Leptin and Grehlin and, similarly to how Melatonin and Cortisol restore broken cells, these hormones attempt to balance the body’s understanding of its dietary requirements when it awakens. A lack of sleep can result in a too small amount of these hormones being released so, upon waking, the human body may have a raised perception of appetite as Leptin and Grehlin have been unable to combat this effect.

For adults the average amount of sleep that should be accumulated per day to combat these effects is around eight hours. Those who gain this amount of sleep are more likely to have lower BMI levels than those who do not.

Many studies have shown that there is a circular relationship between exercise and quality of sleep. According to Singh et al’s study in this area, published in Sleep: Journal of Sleep Research & Sleep Medicine in February 1997, exercise significantly improved all subjective sleep-quality as well as combating depression.

These findings suggest that the more one exercise, the more it is possible to gain better sleep and this helps improve, of course, health and ultimately weight as calories burnt during exercise work in tandem with hormones released during sleep. Interestingly enough, the correlation works in the opposite way too – a great night’s sleep improves energy levels and so the body will want to burn this off. More sleep means the body is better equipped for exercise and ultimately can result in much higher levels of health and fitness.

About the author

Kieron Casey is a BA (Hons) Journalism graduate who blogs regularly on a number of topics including health, fitness, cot duvets and baby bedding

Post new comment

The content of this field is kept private and will not be shown publicly.

Disclosure: We review and test many products on this site. Nobody pays us to review their product. However, if you end up purchasing one of these products we sometimes receive a small fee from the merchant. This helps to keep the site maintained and running.

User login

Theme provided by Danang Probo Sayekti on Hostgator