When you shop for clothes you see plenty of selection in sizes 0, 2 and 4, but fewer in sizes 12 and 14. "It's everywhere." But according to a report published in the Journal of the American Medical Association, being thin might not be in your best interest in the long run.When you shop for clothes you see plenty of selection in sizes 0, 2 and 4, but fewer in sizes 12 and 14. "It's everywhere." But according to a report published in the Journal of the American Medical Association, being thin might not be in your best interest in the long run.