Sleep
Too little sleep increases hunger and the urge to snack – adults are advised to get 7 to 9 hours, teenagers 8 to 10. An underrated lever.
Ausführlich erklärt
Sleep isn't wasted time – it's when your body sorts out its hormones, repairs muscles and tidies up the brain, and it also affects your weight. The US National Sleep Foundation (NSF) recommends 7 to 9 hours a night for adults and 7 to 8 from the age of 65; the American Academy of Sleep Medicine (AASM) specifies at least 7 hours for adults. For teenagers aged 13 to 18, the AASM recommends 8 to 10 hours, for school-age children aged 6 to 12, 9 to 12 hours, and for three- to five-year-olds, 10 to 13 hours including naps. Exact needs vary a little from person to person.
What happens when you don't get enough sleep? In a study led by Karine Spiegel and Eve Van Cauter (2004), after just two nights of four hours' sleep each, the hunger hormone ghrelin rose and the satiety hormone leptin fell. The result: a bigger appetite, especially for sweet, salty and starchy foods – and, in everyday life, often less energy for exercise. At the same time, the body processes sugar less well because insulin sensitivity drops. In large observational studies, people who consistently sleep very little are more often overweight – and in children, this link is even clearer.
Good sleep habits are known as sleep hygiene: regular times wherever possible, including at weekends; a dark, cool and quiet bedroom; ideally no screens in the last hour before bed, because bright light can suppress the sleep hormone melatonin and exciting content keeps you awake; no caffeine after early afternoon; no heavy meal right before sleeping. Exercise during the day improves sleep; only very intense exercise shortly before bedtime can disturb it for some people.
For families: children who don't get enough sleep aren't just grumpy – they're often hungrier too and find it harder to concentrate. A fixed bedtime routine and keeping phones out of the children's room are two particularly effective measures. If you sleep badly over a long period despite good habits, are very tired during the day, or snore loudly and someone notices pauses in your breathing, talk to your GP – sleep disorders can be treated.