This study aimed to investigate the association between awareness of having a chronic disease with food habits and dietary quality among 320 male manufacturing workers in their 40s. Participants were categorized into groups. The first group comprised workers who were aware of having chronic diseases (ACD, n=160) and had been diagnosed with any one or more of the following major chronic diseases: Metabolic syndrome, hyperlipidemia, hypertension, obesity, and cardiovascular disease. The second group comprised those who had experienced none of the above diseases were classified as a group of people who were a ware of not having chronic diseases (ANCD, n=160). The mean age of the subjects was 44.2 years. The mean weight (P＜0.001) and body mass index (BMI; P＜0.01) were significantly higher in the ACD than in the ANCD group. The frequency of alcohol consumption and the number of current smokers were not significantly different between the two groups. Dietary attitudes were not significantly different between the two groups. The frequency of egg consumption was significantly higher in the ACD group (P＜0.05). Picky eating, vegetable intake, checking nutrition labels, and healthy eating behavior were not significantly different between the two groups. The frequency of exercise was significantly lower in the ACD group compared to the ANCD group (P＜0.05). The mean nutrition quotient (NQ) score was 51.9, with no significant difference between the two groups. Based on these results, the awareness of suffering from chronic diseases was not significantly related to dietary attitudes, food habits, and overall dietary quality among production workers. Therefore, there is a need to develop and implement nutrition education programs to inculcate an awareness of health status that can lead to dietary changes.