Craig, 44, who appeared in three Bond movies consecutively, has been advised by his friends to hit the gym again, reported Daily Star online.
"He spent months beefing up for Bond. He needs to get back in the gym and start a nutritional plan to regain his Bond-esque muscles," a source said.
"Having a flabby stomach is not really his style," the source added.
Craig has played role of James Bond in 2006 release "Casino Royale", 2008 release "Quantum Of Solace" and "Skyfall", which released in 2012.
