Why a lack of sleep might make you fat

Everyone love a good a good night’s sleep. After a few sleepless nights we all start to feel a bit worse for wear.

Some researchers even believe sleep is essential to help clear unresolved conflict and problems we’ve had during the day. I’m sure most of us can attest that after a good night’s kip, the person we thought should be thrown into deep dark hole never to seen again, really isn’t so bad.

Although sleep certainly has a huge affect on mental state and fatigue level, many of us battle through it.

As I tell my clients during Personal Training sessions, if you want to look your best, get to bed.  The evidence is in and sleep is essential for being lean, fit and healthy!

It turns out a lack of sleep is a huge contributor to obesity.

Why is not sleeping enough is so detrimental?

When we don’t sleep enough it affects the hormones leptin and ghrelin. These are hunger and satiety hormones, meaning they can either increase or decrease your hunger levels. When you sleep poorly leptin levels decrease and ghrelin levels increase. This is bad for reduced hunger levels as it should be the other way around. Basically if you don’t sleep enough, you’ll naturally be more hungry all the time.

For example in a study comparing 4 hours sleep vs 10 hours, when participants had only 4 hours sleep, they had a 24% increase in hunger. Then when asked to rate appetite for a variety of foods from one’s high in salt, sugar and carbohydrates.  To fruits, vegetables, and protein rich foods like dairy, eggs, meat and fish, overall they had a 23% increase in appetite for all the foods.

However they had a 33-45% increase for foods high in starchy carbohydrates, salt and sugary junk foods.

In layman’s terms you’ll want to eat lots of processed food, and skip the healthy foods.

If you want to make it easier to manage your appetite and waistline, getting a good night’s sleep is a must.

Unfortunately this isn’t the only negative affects to sleep deprivation.

A lack of sleep might increase your waistline, and decrease your arm size…

If you manage to push past the appetite increasing effects of sleep deprivation and lose weight, you’ll be slightly frustrated to find out new research shows you’ll actually be losing muscle!

In a study recently, they compared 8.5 hours sleep with 5.5 hours sleep in a metabolic ward putting everyone into a calorie deficit to create moderate weight-loss.

For anyone who does not know what a metabolic ward is, this is when participants are pretty much kept under lock and key and all they food is weighed and measured. They are not able to eat anything except what they are given and must stay at the facility.

This means no cheating, no eating a chocolate bar and pretending it didn’t happen. As we would expect, both the long duration and short duration sleep group lost exactly the same amount of weight.

Calories count and sleep doesn’t change that. A lack of sleep just makes it harder to eat less calories as you get more hungry. These people had no choice however, they could only eat what they were given.

However this study also measured body composition to see where the weight people lost came from, using Dual-energy X-ray absorptiometry by far the most accurate way to measure body composition.

Shockingly the short duration sleep group lost 55% more muscle than the long duration sleep group, that is huge!

It means a lack of sleep could massively impede your ability to lose fat even if you manage to create a calorie deficit. It means even once you’ve lost weight, you won’t look toned or lean because you’ll of lost your muscle. As the lovely looking diagram I stole from google shows this isn’t good.

In the pictures below both people lost weight. However if they lost muscle it left them smaller but still looking soft. However if they just lost fat, they look lean and toned since muscle makes you look lean and toned.

As you can see, sleep is really important and worth prioritising. It’s actually one of the reasons we get such good results at our gym Renaissance Fitness, we prioritise sleep. In the next post i’ll delve into how to sleep enough with a few key secret strategies.