Well this is unexpected...
Fast Food May Help You Recover
A new study in the International Journal of Sport Nutrition and Exercise Metabolism has found that fast food from McDonald's is just as good for glycogen resynthesis (i.e. recovery) and subsequent performance as sport foods recommended for this use. The research team measured a large number of variables related to recovery—from blood cholesterol to thigh-muscle glycogen content to time-trial performance—and couldn’t find any significant differences between the two refueling approaches.
... In many ways, the Montana result recalls the chocolate milk studies of several years ago. Those studies generally found chocolate milk to be as good for recovery as specially-formulated sports drinks. Respected Boston runner and nutritionist Nancy Clark, R.D., says the new study doesn't surprise her. "I haven’t yet seen a study where a commercial supplement outperforms real foods," she notes. "The supplements may seem impressive because they offer a precise ratio of carbohydrates to protein, but you can get the same from tastier, less pricey real foods with adequate carbs, protein, and calories."
Full article: http://www.bicycling.com/training-nutrition/nutrition-weight-loss/fast-food-may-help-you-recover
I'll admit I often get a bag of McDoubles on my way up to the cabin and throw them in the fridge as a quick protein and carbs snack. Guess I don't have to feel so guilty about it any more.