Studies show that those who sleep less than 6 hours per night are more likely to be overweight and find it harder to lose weight. Our hormones, or chemical messengers, can help us to understand why this is the case.
Leptin and ghrelin
Ghrelin is a hormone that tells us when we need to eat. The less we sleep, the more ghrelin we produce. Leptin does the opposite of ghrelin; it sends a signal to the brain to let us know we’ve eaten enough. The less we sleep, the less leptin we produce. Lack of sleep and these two hormones makes us more susceptible to overeating and less likely to feel satisfied afterwards.
Cortisol
This is a stress hormone that breaks protein down into glucose. If there’s too much glucose, it gets stored as fat. Excess cortisol makes the body use soft tissue like muscle for its energy needs instead of fat. Our cortisol levels increase the less we sleep at night. It also triggers a hunger response in the brain, causing us to think we’re hungry.
Melatonin
Melatonin is a powerful antioxidant that manages our circadian rhythm (sleep-wake cycle). It’s released at the onset of darkness to prepare our bodies for sleep. Studies have linked melatonin to increased metabolism.
Insulin
Insulin helps our bodies to absorb glucose from the bloodstream. Not enough sleep can lead to too much blood sugar, and that can lead to insulin resistance. This means the body will produce more and more to function and could eventually lead to diseases like diabetes.
Growth hormone
Our bodies create more growth hormone whilst they’re asleep. It stimulates cell reproduction, regeneration, and growth. More growth hormone means a higher metabolism, meaning we burn up energy more rapidly. This gives us the potential to lose weight faster.
We need to value our sleep and prioritise it as we do with diet and exercise. Our bodies need time to rest, recover and rejuvenate, and sleep plays a vital part in this. So, rest up and sweet dreams.
