I was recently talking with an old hiker and he said that one trail food he swore by was dry dog food.

It sounded crazy at first, but he gave me a solid argument regarding its benefits (already being dehydrated, cheap, nutritious enough). He did say that he would never eat it exclusively, since it doesn't have all the nutrients people need (e.g. vitamin C). He did say that it was definitely a good filler food though. I did a bit of research, and the ingredient list of most dog foods seems no worse than human food. I was not able to find any information on nutritional facts, however (calories, fat content).

So what do you say? Was he being sincere, or pulling my leg?