I have eaten / I have already eaten

If somebody asks you "Have you eaten?", is there any difference in meaning between answers one and two below?

1. I have eaten.
2. I have already eaten.

Not really. In the end, all you are really saying is, "Yes."; the rest is just extra information. You are using the present perfect tense which usually implies something that was done in the past, something that might happen now and will probably happen in the future. Typically, you would use this form if the response was something like:

"I've eaten, but I could eat again."

or something like that.