"He is so sensitive about his weight. You will never see him shirtless. Backstage, he always keeps his dressing room closed.
"At photo shoots, he will not change on set. He goes back to his dressing room whenever he needs to take his clothes off. He is not in bad shape. He's just so shy about showing off his body," a source said.
The 42-year-old recently revealed that getting divorced from Miranda Lambert was the best "diet ever", reported Female First.
"I just think, not the actual break-up part, but just the whole stress of getting through all of that is just weird. No I am doing great, but it's just I wasn't eating as much I guess. I wasn't like going to the gym, just stay as busy as you can to keep your mind off anything," Shelton had said.