It seems like every day there's a new report about something you shouldn't eat. The constant bombardment of information about food and health can confuse anyone, but for people who have the eating disorder orthorexia nervosa, it can be downright dangerous. People with this condition are obsessed with eating healthful food and have constructed strict diets that they follow religiously. Although many people who have orthorexia nervosa become underweight, thinness is not their goal -- nutritional purity is. Among the signs of orthorexia nervosa are: spending more than three hours a day thinking about healthful food; planning meals days in advance; feeling virtuous from following a strict healthful diet, but not enjoying eating; feeling socially isolated (such strict diets make it hard to eat anywhere but at home); and feeling highly critical of those who do not follow a similar diet. Although the psychiatric community does not officially recognize orthorexia nervosa as a disorder, those with the condition benefit from psychological treatment and sessions with eating-disorder specialists.On the next page learn how buildings can make you sick.