The stunner, who has posed nude for PETA, was slammed by activists after pictures appeared in August showing her coming out of the fast food chain (long accused of using battery chickens in its food).
But, she has now defended her vegetarian stance saying that she was actually doing a good deed, which went all wrong.
"I'm such an idiot - the thing was I was in there because this homeless guy was hungry. I went past and thought 'I'm going to go in and get him some wedges.' I was actually doing a good deed. It's so me to end up the other way around where I've done damage," The Daily telegraph quoted her, as saying.
Earlier, Monk had protested against KFC for their animal rights form, and has claimed that she is a committed vegetarian.
After her PETA campaign, Monk said that she only ate at vegetarian restaurants as they have the "best food".
She also criticised KFC eaters, saying: "I think the message to KFC eaters (is that) you should think about what you're eating. If you're eating deformed animals that are being induced by hormones, you know, it cannot be good for you."
The health of the homeless man Monk helped is unknown.