A new, not-yet-a-diagnosis eating disorder is becoming more prevalent in North America: Orthorexia Nervosa. Unlike Anorexia or Bulemia, Orthorexia's focus isn't on 'getting thin', it's on 'eating healthy'. However, it is not the intention to eat healthy that is the problem for an Orthorexic, it is the extent to which it's taken. More and more foods they formerly enjoyed are cut out as not being healthy enough to make the grade. Meals with friends and family disappear, as no one else can live up to their dietary requirements. Restaurants and social meals likewise disappear. Many Orthorexics report feeling socially isolated, exhausted by their obsession with eating healthy, and depressed. Eventually and ironically, the health of Orthorexics declines as the restriction and 'purification' of their diet means it becomes deficient in key nutrients needed for life.
Orthorexia is getting more exposure as a problem for those affected by it; it was recently featured on an episode of The Current with Anna Maria Tremonti. The episode is available here.
More information on Orthorexia Nervosa, courtesy of the National Eating Disorders Association here.