Everyone on board with the “sleep divorce” trend may be onto something.
Poor sleep can throw a wrench into healthy eating habits, making it hard to stick to a nutritious diet.
And if you share a bed with a partner who sleeps poorly, their sleep could be messing with your diet, too, according to a new study.
Researchers followed 204 cohabiting couples over three months, asking them to complete questionnaires about their sleep and diet, along with diaries tracking their healthy eating efforts.
Those who reported poor sleep said they made less effort to eat well and felt less confident in their ability to maintain healthy eating habits. Their well-rested partners reported the same struggles.
“People with a sleep-deprived partner were essentially saying they have less confidence in their ability to follow a healthy diet, so they engage in less effort to do so,” corresponding author Jean-Philippe Gouin said in a press release.
While we’re more likely to choose a partner who share our lifestyles and habits — whether that’s someone who likes to cook, exercise or prefers an early bedtime over a late night.
But once couples move in together, their routines and eating patterns can start to merge.
And sharing a bed with a partner who either has poor sleep hygiene or disruptive sleep behaviors like snoring affects quality of sleep for both people.
Despite getting adequate rest, people who reported sleeping well in the study were more likely to be exposed to calorie-dense food, such as chips, cookies, candy and other ultra-processed foods because of their partner.
At least one person in each couple was overweight or obese and actively trying to improve their diet or physical activity. Nearly 96% of participants reported they were trying to change their eating habits.
Over the course of the study, sleep quality didn’t change significantly.
Diet quality, however, improved modestly, with women reporting healthier eating habits and making more serious attempts to stick to a diet.
Still, the researchers caution that the findings don’t prove poor sleep habits directly cause unhealthy eating habits.
The participants self-reported their sleep and eating patterns, which means that future studies can use objective measures to track these factors.
In the meantime, this study could highlight new ways to improve diet, especially through joint-effort treatments that improve one partner’s sleep to help maintain healthy eating in both people.
Additionally, Gouin says social contexts need to be taken into consideration when looking at poor eating, including the influence a partner’s behavior has over the other.
“If we want to make changes that are long-lasting, both partners need to work together to change the home and food environment so that it is easier to maintain healthier habits over time,” Gouin said.
