MILAN – There seems to be one fundamental rule: a varied diet ensures good quality sleep. This discovery was made during research conducted by the Perelman School of Medicine at the University of Pennsylvania in the United States, which tried to investigate the link between obesity and sleep. Or rather, to understand how the way we eat is linked to how we sleep. The team, led by Michael A. Grandner, has argued that people who do not get much sleep consume more calories and lack many nutrients.
The scientific study
To do this, the team at the University of Pennsylvania collected and analysed a huge wealth of data from the National health and nutrition examination survey. The sample was representative of all age groups and both genders, and was then divided into certain groups on the basis of the number of hours actually slept: Very short sleep (less than 5 hours per night), short sleep (5-6 hours per night), normal sleep (7-8 hours per night, used as the reference group for the study), and long sleep (9 hours or more per night, too much). Of course, eating habits were also recorded, including what was eaten, when and how much.
What was revealed was that our diet is related to our sleep. In fact, calorie intake varies according to the group and the number of hours slept. The people who slept the worst were those who usually had an unvaried diet that was lacking in some nutrients and much higher in calories. They were then followed by those who say they slept 6 hours per night, then by the late risers, excluding those who got just 4-5 hours of sleep, slightly surprisingly. Conversely, those who slept best had quite a varied diet most of the time, which alternated every day between varied foods that are rich in protein, vitamins, carbohydrates, minerals and fibre. Not to mention drinking plenty of water throughout the whole day and avoiding alcohol, which shortens the important REM stage of sleep.
People who don't drink much water have short sleep
Specifically, Grandner very much links very short sleep to a lower intake of water, lycopene (found in red- and orange-coloured foods, such as tomatoes) and carbohydrates. Short sleep was linked to a lack of vitamin C, water, selenium (found in nuts, meat and seafood) and more lutein/zeaxanthin (found in green, leafy vegetables).
by editorial staff