Our 5 year old yellow lab has started taking food off the counter and eating it. She is very well fed. We play with her and we have trained her to do many things. She is very mellow. Lately she has started doing this. She knows she has done wrong when I scold her, but she even did it today. I left part of my lunch on the counter and went to the restroom. When I returned, she had got my lunch down and ate it! What can we do to stop this? (Besides not leaving anything on the counter).

" (Besides not leaving anything on the counter)." sorry that is exactly where you have to start. She has now learned the counter is a source of food even with the scolding. As long as you keep allowing food within her reach you will not be able to retrain her. Once you put the food proeprly away then you can start new training about what is hers and what is "NOT YOURS" The not yours command was likely never trained into her, she does not know what is yours and what is hers. I can not give you full obedience training on this site but you can get help from local dog training schools.

"Not yours" seems like a big mouthful to say to a dog... I would go with the age-old "leave it" command.

To make her stop:

Set her up to fail. Place pots and pans on the edge of the counter with a tid bit right next to it. The minute she hits the pots and pans, they'll fall and make a huge racket. That should deter her from wanting to continue it. And of course, not leaving things within reach for her to get. They also make mouse traps for dogs that are counter surfers. That might be an option for you as well.. Its pretty much the same concept as the pots and pans... The pots and pans are just easy access and free... :)

You can also sneak up on her and scare her with the "leave it" command in a very scary voice.. also make noise... Let her know that what she is doing is not giving her a good reward.

I had a counter surfer.. and it probably took a good year with sneaking up on her and letting her scare herself before she gave up. She soon learned that every time she tried to counter surf, something scary happened.