People who eat alone, which is becoming a new trend owing to the increasing proportion of one-person households in Korea, are more likely to become overweight and obese. Therefore, we investigated the association between having a dinner companion and BMI.

A linear regression model adjusted for covariates was utilized to examine the association between having a dinner companion and BMI. Subgroup analyses were performed, stratified by age group, gender, household income, educational level and occupation.

We used the data from the Korean Health and Nutrition Examination Survey VI. Our primary independent variable was having a dinner companion while the dependent variable was BMI.

In total, 13303 individuals, aged 20 years or over, were analysed.

Compared with the solo eating group, BMI was lower in the family dinner group (β=−0·39, P<0·01) but not in the non-family dinner group (β=−0·06, P=0·67). The subgroup analysis revealed that the difference in BMI was most significant in young generations, such as those aged 20–29 years (β=−1·15, P<0·01) and 30–39 years (β=−0·78, P=0·01).

We found that people who eat dinner alone are more likely to become overweight and obese than those who eat with their family. This association was stronger in males and young adults than their counterparts. Considering the increasing trends in the proportion of single-person households and solo eating, appropriate intervention is needed.