From the time of ancient Rome, it was stated that physical exercise, added to a good diet, were the key to people’s mental well-being. Although the premise is still valid nowadays, young people do not seem to understand it, as being overweight is a real public health problem in this population subgroup. The objective is to know the university population eating habits, seeing how these are related to their body and their emotional well-being. It is hypothesized that those who have worse eating habits will suffer greater discomfort with their body image, in the same way that their mental well-being will be diminished. 600 university students (300 women and 300 men) filled out the Lifestyle and Health Questionnaire (Giménez-García Ballester-Arnal, 2017). For this work where chosen those items related to food, body image and mental health. People who take care of their diet have a greater satisfaction with their body ( 2 = 45.86; p.001). At the same time, people who are proud of their body image report a greater emotional well-being ( 2 = 35.02; p.001). Youth who define themselves as a fat person report worse mental health than thin or normal-weight people ( 2 = 17.26; p= .002), taking significantly less care of their diet ( 2 = 23.34; p.001). Emotional well-being, body image and diet care are closely related. A balanced diet not only improves physical health, but also increases mental health. Health and education professionals should encourage young people to improve their diet. This will improve both body satisfaction and emotional well-being.