Mental illnesses affect a significant proportion of the population. Some studies show that up to one in two people may experience various mental disorders during their lifetime. This term includes illnesses such as schizophrenia, depression, bipolar affective disorder (BPAD), addictions and others. These conditions not only affect our 'spirit', but often also have a negative impact on the body. A correlation has long been observed between mental illnesses (including their pharmacotherapy) and the incidence of obesity, metabolic syndrome and diabetes. This connection is the resultant of many factors, some of which I will try to outline.