I answered my own question, looked it up on google.
"In the coastal and lower Andes mountains, degus eat mostly simple forms of plant life and tubers. They do not eat anything with sugar in it. Because of this they have evolved in such a way that they are not capable of assimilating glucose into their systems. It is as if they are diabetic.
The best food for them will not contain any sugar. Guinea pig food is a good idea with the occasional carrot. Hay blocks, timothy hay and alfalfa is also very good for them. Sweet potatoes are good as are other yellow vegetables.
I have read that potato skins and roots are very toxic to them so make sure that when you give them sweet potatoes that there are no signs of roots or skin, only the yellow stuff itself. Nuts such as sun flower seeds and peanuts should only be given as a treat, if their food has either of these in it, take the time to remove then and give a few of them as a treat once a day."
It is the diet that they are fed in captive life that causes the problems.
I am still interested to hear if anyone else has degus though. How are they as pets for you?
I'd never seen them before. Some folks are pretty anti-rodents when it comes to pets, but I've had rats, hamsters, gerbils, etc, and from what I read, the Degu's seem to be pretty comparable to the others, and the diet thing looks to be pretty common.