@peter jeffrey cobb,
Also Pete, in case you or any of your relatives happen to have diabetes I'd like to write a note on the medication you are taking because the drug risperidone and similar drugs CAN (but may not) cause an increase in blood sugar. They say to not change your diet, but in this case I'd say make sure your following a diet similar (minus the cookies, potato, white rice, and chocolate) to the person you live with. =)
The NIH site says this: (http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000944/)
If you have schizophrenia, you are more likely to develop DIABETES than people who do not have schizophrenia, and taking risperidone or similar medications may increase this risk. Tell your doctor immediately if you have any of the following symptoms while you are taking risperidone: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. (These are diabetic symptoms!!!) It is very important to call your doctor as soon as you have any of these symptoms, because high blood sugar that is not treated can cause a serious condition called ketoacidosis. Ketoacidosis may become life-threatening if it is not treated at an early stage.