The link between food and sleep
Sleep is food for the brain. Too little sleep is bad for us.
Infants need 12 to 15 hours of sleep every 24 hours, and toddlers need 11 to 14 hours. Primary school-aged children need nine to 11 hours, teens need eight to 10 hours, and adults should aim for seven to nine hours of sleep each night. Seniors don’t actually need any extra sleep, however, because they tend to sleep lightly and awaken more often during the night, many may benefit from a daytime nap.
During times of rapid growth and development, such as infancy, childhood, the teenage years, growth spurts and pregnancy, our bodies also need more sleep. Biological sleep patterns shift towards later times for both sleeping and waking during adolescence, meaning it is natural for teenagers to fall asleep later at night and sleep later in the morning.
Lack of sleep has been shown to cause weight gain. Research suggests that less sleep makes the body work differently, and that being sleep deprived has a similar effect on the body as being overweight. Both decrease glucose tolerance and insulin sensitivity, which may result in diabetes.
Less sleep also alters two key hormones: leptin and ghrelin. Leptin reduces hunger. Lack of sleep, especially when associated with stress, reduces leptin levels.
Ghrelin is the hunger hormone. It tells us that we are hungry and need to eat more. When we don't get enough sleep, our bodies make more of this weight-sabotaging hormone. Just one night of sleep deprivation can be enough to increase ghrelin levels.
Ghrelin not only increases hunger, it also reduces energy expenditure and promotes fat retention. In a recent study, 10 overweight people followed a weight-loss diet and compared the amount of weight they lost during a week of normal sleep and a week with only five-and-a-half hours of sleep each night.
They lost the same amount of weight in each phase (they were in a controlled environment), but on the sleep-deprived phase, they lost 55 per cent less fat. So, lack of sleep can sabotage our efforts to lose those jiggly bits and actually leave us with proportionally more fat and less muscle.
To help with sleep, it’s important to maintain a routine:
- Children especially thrive with routine. It could be something like bath or shower, brush teeth, bed, read a story, then lights out.
- Eat the evening meal at least two hours before bedtime. Keep it light and not too rich/spicy. Caffeine, alcohol and cigarettes all disrupt sleep. Cease drinking coffee after 2pm in the afternoon, and remember that caffeine is also found in chocolate, chocolate drinks, cola and energy drinks.
- Some foods/drinks are thought to help us sleep, such as certain herbs, tea, and warm milk. This varies depending on the individual, but is generally psychological.
- Go to bed at the same time each night and get up at the same time each morning, even at weekends. This is especially important for teens who can disrupt their body clocks by going to bed later and later, and sleeping in longer and longer.
- Brief naps can help boost our energy and concentration and make us work more efficiently, if we plan them right. Naps that are too long or too close to bedtime can interfere with regular sleep.
- Have a warm bath, perhaps with lavender oil, before bedtime. Learn mindfulness techniques to help with relaxation.
- Keep the bedroom for sleep. Avoid having devices like TV, tablets or any other screens in the bedroom. Avoid talking on the phone or eating in bed. Some people find reading a book helps them go to sleep. Keep the bedroom cool, dark and quiet, with a comfy mattress and pillow.
- If you can't fall asleep after 20 minutes, get up and go back to bed once you feel tired.
- Try keeping a diary or to-do list. If we jot down thoughts during the day, we are less likely to stay awake worrying or stressing.
- Do at least one hour of exercise each day, but no closer than an hour to bedtime. When we're physically tired, we sleep better.
Written by Lisa Wynter. First appeared on Stuff.co.nz.
Related links:
Why those who go to bed early are healthier
Why do we struggle to sleep in the heat