I took Thing Two to the doc last week and it turns out he is underweight. He is 4' 9" tall and weighs 71 pounds. His BMI is 15 - the low end of normal is 18. So the "prescription" is three hefty meals a day, three snacks of nuts, fruit and cheese a day plus 2 vitamin and calorie laden shakes (think Boost or Ensure) plus a bowl of ice cream every night at bedtime. The high fat, real cream, super yummy ice cream.
As he scarfs down his bedtime "prescription" he asks me don't I wish I needed the same medicine that he does.