A questionnaire was completed by 9,099 men and women aged ≥40 years living in Tokorozawa, Saitama Prefecture, Japan. The subjects were recruited via random sampling. We analyzed the data of a subset of 3,143 elderly subjects aged 65 and over. The questionnaire included gender, age, body mass index （BMI）, school education, household income, marital status, residence status, and dietary style. QOL was examined across five domains: physical, psychological, social, environmental, and total. To ascertain the relationships between the abovementioned items, we used IBM SPSS Statistics version 23.0 and HALBAU7.

　We ascertained the demographic information of participants and classified them in the following groups based on dietary style: solitude-solitary eating （ n ＝78）, cohabitation-solitary eating （ n ＝72）, solitude-meal sharing （ n ＝109）, and cohabitation-meal sharing （ n ＝1,297）. Results of a two-way analysis of variance showed that the effect of dietary style was observed in the physical domain of QOL. There was no significant interaction between the two. Mean QOL scores across the five domains were lowest in the cohabitation-solitary eating group. Results suggested that elderly people with solitary eating who live together were more strongly influenced by eating habits than those who live alone.