By Debbie Emery - Breaking Celebrity News Reporter

Who ate all the kibble?

Life as the First Dog isn't all fun and games, as Bo Obama has found out after he recently piled on too many puppy pounds.

When President Barack Obama made a surprise appearance at the White House's first "kids state dinner," hosted by wife Michelle on Wednesday, he surprised the young diners by revealing that Bo is on a diet and begged them not to feed him any fattening treats.

"I only have one request for you, and that is try not to drop any scraps on the floor," Obama told the group of assembled junior chefs in the East Room, reported U.S. News & World Report. "Because Bo... Bo is on a diet right now and he will eat anything that he sees, especially some of the tasty meals that you guys have prepared."

The curly haired 3-year-old Portuguese water dog has been getting a little thick around the middle and he has now become the latest recruit in the Obama's fitness obsession, which recently included Michelle telling Olympic gymnast Gabby Douglas not to eat an Egg McMuffin.

The First Lady has been actively trying to get the country onto a nutritious path and told the young chefs who had won a nationwide recipe competition that the dishes they created proved that fun eating can be "hea