Background According to the Sasang constitutional medicine, eating habits according to the characteristics of Sasang Constitution (SC) types affect management of chronic diseases and health conditions. The aim of this study is to identify the association between eating habits, such as breakfast, eating frequency, and energy intake, according to SC, and quality of life. Method This study is a cross-sectional study of people aged 33 to 55 years, sampled by stratification based on population distribution. The SC types were classified into Taeeumin (TE), Soeumin (SE), and Soyangin (SY) using a structured questionnaire (KS-15). Items examined regarding eating habits were whether the subjects had breakfast; the frequency of eating such as breakfast, lunch, dinner, and after-dinner snacks; and energy intake surveyed using a food frequency questionnaire. As for quality of life, SF-12, which is widely used worldwide to assess health conditions, was utilized. A regression analysis was conducted on the relations between eating habits according to SC and quality of life. Results The SC distribution of the 3,895 subjects was 47% for TE, 22% for SE, and 31% for SY. The scores indicating quality of life differed for TE and SY depending on whether they ate breakfast and eating frequency groups, and those of SE varied depending on levels of energy intake. A regression analysis having adjusted all covariates demonstrated for TE a positive relation between the eating frequency of three times per day or more (compared to 1.5 to 3 meals per day) and quality of life (B=1.365, p<0.001). For SE, there was a negative association between low energy intake (compared to adequate energy intake) and quality of life (B=-1.642, p=0.004). Meanwhile, no relation was found between eating habits and quality of life for SY. Conclusion This study identified the association between eating habits according to SC types and quality of life. For TE, it was found to be important to eat evenly dispersed adequate amounts as opposed to overeating or binging at once. For SE, adequate energy intake affected good quality of life. This study suggests that eating habits based on SC improve quality of life, and health management customized for each constitution should be performed in the future through proper eating habits.