Obesity is a medical issue and frequent cause of premature death faced by a large proportion of persons with mental illness. The medications that we must take often have an effect on metabolism, directly causing weight gain and sometimes diabetes. The medications often make it more difficult to get physical exercise because of the sedation (which is common among numerous classes of these drugs.) Many psychiatric drugs also increase appetite.
It is harder for someone with a mental illness to cut back on food intake, because going hungry, even if for a relatively short time, sometimes has a destabilizing effect. Lack of food affects which parts of the brain are used and this can sometimes create a "fight or flight" reaction. This is a ticket to psychosis for people who have that tendency.
In the mental health treatment system, in which people are given medication, psychotherapy and milieu therapy on an outpatient basis, fattening foods are served. Some mental health treatment venues do not make an effort to cut back on the fat and sugar intake in the meals that are offered. It is not always practical for someone with mental illness receiving treatment at these places to supply their own healthier food, as many do not have access to food preparation facilities, or might lack the income to pay for their own food.
Many people eat poorly merely as a bad habit, without having a good reason. It might never occur to someone with mental illness that they ought to watch their calorie intake and possibly eat foods that are more nutritious.
Healthier eating habits seem to normally come with middle-age for persons who do not have mental illness. Persons with mental illness do not always have the same learning curve and in some respects, we may continue to behave as though in our twenties.
I became overweight for many of the above reasons, and acquired associated health problems. However, a year or two ago I decided I had better lose some weight. My approach was to make an ongoing change to eating habits. I increased my intake of fresh fruit and cooked frozen vegetables. I cut down on fast food and cut drastically down on candy and desserts. I prepare a fresh, healthy meal for dinner most nights for my wife and myself.
Exercise has been more difficult. It is easier to eat less, since that involves not doing something, rather than doing something more.
So far, I have lost twenty-two pounds and haven't gained this weight back. I look forward to again having flat abs as I did when younger. I'm not looking for rapid, drastic weight loss. Such a loss of weight based on an extreme diet will often reverse itself as soon as the dieting is stopped. It works better to make an ongoing change to eating habits, a change that can be realistically sustained, and which doesn't end when a goal weight is reached.
It doesn't do a person much good to have successfully treated their mental health problems if, at the same time, one has bought a premature death due to poor diet. Psychiatric drugs often cause weight gain. However, a person with mental illness can sometimes compensate for this with diet.