Sleep and weight gain
Do you sleep like a baby, or struggle to squeeze in six hours of quality sleep a night? Could losing weight be as simple as finding time to catch an extra forty winks? If you’ve read the news recently, you may have heard of the ‘sleep diet’ – an idea that sleeping longer could help prevent weight gain.
This is based on research published in the medical journal Sleep, which suggested that inadequate sleep increases the expression of genes related to weight gain. Scientists studied over a thousand sets of twins and found that, not only is there a genetic link in the amount of sleep we typically have, but that sleeping for less than seven hours a night strengthens the relationship between genes and weight. Put simply, your genetics affect both your sleep pattern and your weight, but this study suggests that you may be able to overcome the genetic influences on your weight by sleeping a little bit longer.
Why do you need sleep?
If rock stars are to be believed, there’s plenty of time to sleep when we’re dead, isn’t there? Sleeping in is often viewed as a lazy trait, and going to bed early as boring. For many of us, sleep is a minor inconvenience in between work, spending time with friends and family, catching up on television, and getting up early to squeeze in a workout – and we’re sleeping less and less as a result.
So, what does sleep do? In our deepest and most restorative sleep, blood pressure drops and our bodies get the chance to fully relax. At the same time, blood is driven to the muscles, providing nutrients for recovery and repair. Sleep is also known to regulate mood and help our brains function better, by improving learning and memory functions.
If you want to know more, watch this excellent TED talk on the subject!
How does sleep deprivation affect weight?
To say that the relationship between sleep and weight is complicated is an understatement. More and more research is being carried out in this area, and it appears that there’s a dynamic relationship between the body’s internal clock, appetite and metabolic rate.
In studies where people have been limited to four hours of sleep a night for several days, changes in appetite hormones have been observed, and appetite for sweets, salty snacks, fatty and starchy foods seems to increase.
There are more than 65 published research papers that have linked sleeping for fewer than six hours a night with increased weight. One large study found that adults who slept for fewer than five hours one and a half times more likely to be obese; while children who slept for fewer than ten hours were almost twice as likely to be obese.
The exact mechanisms are unclear, but probably relate to increased food intake, through changes in appetite hormones along with more waking hours spent eating.
How much is enough?
Sleep experts suggest that between seven and nine hours of sleep is about right for most adults.
Is sleep more important than exercise?
Both sleep and physical activity play important roles in overall health as well as helping you achieve a healthy weight. If you’re trying to sleep more, it’s probably not the early morning gym class that you should cancel. An active lifestyle can help you to sleep better and relieve other stresses, so it’s better to cut down on TV viewing or late-night work than to limit exercise.
What improves sleep?
Tryptophan-rich foods such as milk, meat, fish, poultry, eggs, beans, peanuts, cheeses and leafy veg may help you to sleep better. Tryptophan is converted in the brain to serotonin, the feel-good chemical that is then made into melatonin, which helps regulate sleep. Foods naturally high in melatonin such as tart cherries have also been investigated, but there’s no firm evidence that they’re effective. Eating a healthy, balanced diet like you do on our plan is the best advice in relation to your eating habits.
Getting the environment right in your bedroom can also help you sleep. The temperature should be neither too hot nor too cold, and if the room is as dark as possible, that will help your body produce melatonin. It’s best to avoid alcohol and caffeine before bed, although individual tolerance levels to caffeine vary. And try to go to sleep at a similar time each evening, so that your internal clock gets used to this routine.
And if you can’t sleep?
Tossing and turning, willing your body to relax and sleep, can be counter-productive. Sleep experts agree that if you can’t get back to sleep within 15-20 minutes, it’s better to get up and do something that you find relaxing, then go back to bed when you’re tired. Some people find herbal teas, such as Camomile or Valerian, helpful, but reading a book and listening to soothing music can also be effective. The key thing is not to get stressed about sleeping, and find out what works best for you.