The researchers took 26 adults who regularly slept between seven and nine hours a night and played around with their diet.
They found that when they ate a high-fibre, higher protein dinner that was lower in saturated fat, the participants fell asleep faster (less than 20 minutes) and spent more time in a deep sleep, which is important for memory, our immune system and is when our bodies truly relax.
When participants ate a meal low in fibre, but high in saturated fat and sugar, it was found they took longer to fall asleep (nearly 30 minutes), had a less restful, deep sleep and were associated with sleep disorder.
As we know from previous research, a bad night’s sleep sets us up for craving crappy food, which as we now know, sets us up for a bad night’s sleep and so the not-very-merry dance continues.
“Our main finding was that diet quality influenced sleep quality,” said lead researcher Marie-Pierre St-Onge. “It was most surprising that a single day of greater fat intake and lower fibre could influence sleep parameters.”
St-Onge added that diet changes may help people who suffer from chronically poor sleep.
While a high-fibre diet is already linked to reduced risk of obesity, diabetes, heart disease and bowel cancer, this new research bolsters those health links, albeit for a slightly different reason.
“The finding that diet can influence sleep has tremendous health implications, given the increasing recognition of the role of sleep in the development of chronic disorders such as hypertension, diabetes and cardiovascular disease,” St-Onge said.
Greens, sugar and fat are not the only things we consume before bed that can affect our sleep.
A drink – or three – helps us to nod off faster but can disrupt our sleep afterwards, depending on how much you have. One or two drinks, previous research has shown, may increase deep sleep time while any more leads to a restless, unsettled sleep.