One Partner's Poor Sleep May Influence Both Partners' Eating Habits, Study Finds - Video

Poor sleep may influence more than one person’s eating habits, suggesting sleep quality can affect a partner’s efforts to maintain a healthy diet.

Published in Annals of Behavioural Medicine, the Concordia-led study followed 204 couples living together in Canada for three months. Participants were around 42 years old, and at least one person in each couple had overweight or obesity and was trying to improve their diet.

Researchers assessed sleep and diet using questionnaires at the start, after one month and three months later. Participants also kept diaries for 14 days to record their efforts to eat healthily.

The findings showed that people who slept poorly reported making less effort to eat well and feeling less confident about maintaining healthy eating habits. Their partners reported similar difficulties, even when their own sleep was better.

Researchers suggest this may happen because couples often share meals and food environments. A sleep-deprived partner may be more likely to bring calorie-dense foods such as chips, crackers, chocolate or sweets into the home, making healthy choices harder for both people.

Diet quality improved modestly, while sleep quality remained largely unchanged. Women reported healthier diets and stronger efforts to eat well than men, but gender did not appear to change how one partner’s sleep affected the other’s eating behaviour.

However, the study does not prove that poor sleep causes unhealthy eating. It was observational and relied on self-reported information. Future research could use objective sleep and dietary measurements and examine household food choices, meal planning, partner support and conflict.

Researchers say the findings highlight the importance of considering sleep and eating habits as shared issues within couples. Treatments that improve sleep, such as cognitive behavioural therapy, could potentially be studied as couple-based approaches to support eating.

REFERENCE: Maegan Dymarski et al, Dyadic associations between sleep quality, diet-related self-regulation, and diet quality in couples, Annals of Behavioral Medicine (2026). DOI: 10.1093/abm/kaag041