No, thats complete ****, after eating your bloody supply is favoured towards your digestive system, and exercise will cause the blood supply to divert to working muscles. Either way, all that happens is the stuff you've just eaten floats about in a big puddle of acid in your stomach, and isn't digested, thats not to say it isn't digested properly, its just not digested, and when sufficient blood is provided to the digestive system again, your body goes back to digesting it. Either way, it makes little or no difference, except for the fact that you have a big puddle of food and acid in your stomach, which can a) cause you to throw up and b) cause discomfort/cramps whilst exercising.