Underweight child

My son is so underweight for his age, I have tried everything to add extra calories to his diet and has gone from 59 lbs down to 51.4 in a period of 2 months. He does have ADHD and does not eat well at school, however, he does eat a great breakfast and dinner. He will also eat snacks. He also has kidney disease with protein in the urine and possibly acid reflux so some of the tips for "extra protein" stuff we can not use. He also appears short for his age. Since he is adopted we do not know what runs in his birth family. Any ideas on what to give him to eat?

[Renee Radenberg]

Children with kidney disease usually develop a smaller stature due to the growth hormone and the kidney dysfunction. You can add calories by adding additional fat to his diet instead of protein if his acid reflux is not affected. Here is an example of a shake you can make: 6ozs Non-dairy whip cream, a drop of vanilla extract, and 1 teaspoon of sugar or 1 Splenda. Blend together. The shake provides approximately 400+ calories. Hoped that helped you.