Introduction Worldwide, the burden of communicable disease and maternal, neonatal, and nutritional disorders declined between 1990 and 2013, whereas the burden of non-communicable disease (NCD) increased. 1,2 A sustainable development goal is a global framework to reduce premature deaths from NCDs by one-third. Nutrition-related NCD is important because remarkable transformations of food systems have resulted in a rapid increase on NCDs in low-and middle-income countries. 3 Diet plays an important role in NCDs such as cardiovascular disease, 2,4-13 diabetes, 2,5,8,12 cancer, 2,12,14 mental disorders, 15-17 and chronic obstructive pulmonary disease. 18 Unhealthy diet is a increases the risk of NCDs and provide an opportunity to intervene perfect, appropriately, and synergistically on more than one risk behavior concurrently to prevent NCDs as a whole. 12 It has been recommended that the workplace is an appropriate filed to evaluate lifestyle intervention such as promotion of a healthy diet because many adults, regardless of socioeconomic status, lifestyle, and risk profile can be targeted at once. 9 Globalization of the food supply has increased the need to strengthen food safety. For this reason, the World Health Organization (WHO) is promoting efforts to improve food safety by making the theme of World Health Day 2015 "improve food safety from farm to plate (always and everywhere). " 19 The first step to promoting a healthy diet in a given society is to assess diet behavior; thus, the present study assessed the diet behavior of employees at a medical sciences university in Tehran on Health Day 2015.