HELP!! -- disaccharidase deficiency
 

My son was diagnosed last week with severe disaccharidase deficiency. This means he is unable to digest not only fructose but also sucrose and maltose. The only sugars he can eat in more than tiny quantities are fructose and glucose.

This deficiency/intolerance is usually congenital. In the rare case that it arises later in life, it can be temporary or permanent, and we don't know yet which it will be. We have our fingers crossed for temporary!

Meanwhile, we are in the process of figuring out which foods he can eat and which he can't. In particular, we're trying to figure out what he can eat to fuel up before a practice, game, or workout. He is 13 years old, tall and very skinny. He runs track (800and mile), plays basketball and soccer, and is generally pretty active.

Any advice would be very much appreciated. Thanks in advance!

Disaccharidase deficiency usually involves lactase deficiency, meaning inability to digest milk sugar. Your son's problem seems to be worse. You might read this:
http://www.ncbi.nlm.nih.gov/pmc/arti...00126-0057.pdf
Disaccharidase deficiency also usually means an inability to digest disaccharides, meaning sucrose, HFCS, etc. So pure glucose or fructose might be tolerable, however you say they aren't, so this is even trickier. Invertase might be tolerable. Specialist doctors should be more helpful than a bike forum. However, it is becoming increasingly difficult to find a doctor who is.

Sorry, I should have been clearer. My son CAN tolerate glucose and fructose. He can also tolerate tiny quantities of disaccharides. Thus, the question is, which pre-workout foods have no sugars other than glucose and fructose.

That may be simpler. Maltodextrin is a long-chain polysaccharide composed of only glucose molecules. Everything that Hammer Nutrition makes is simple sugar (disaccharide) free. I'd buy a couple packets of HEED and try them on him, see if he can digest it. Or ask your doctor. Right off, I can't think of a pure glucose commercial sports drink. But I bet you can buy it and make up your own flavored stuff.

Sucrose and lactose are disaccharides, but HFCS is just a mixture of glucose and fructose so it should be okay for those lacking disaccharidase.