Jamie Foxx bragged about his weight loss to Ellen Degeneres recently. And though he joked a lot, he gave some interesting insight into how easily weight gain creeps up. The "Sleepless" actor shared tips on how he was able to drop and add nearly 75 pounds between movie roles. And some of them are going to shock you.

Jamie Foxx didn't see it coming

The "Django Unchained" star brought down the house with his hilarious Denzel Washington impression on "Ellen." But aside from that, he talked serious weight loss. Though fans might not see it, Foxx was beginning to put on pounds.

He didn't really notice it and everyone was too polite to mention it. Jamie says that's a big reason why weight loss gets delayed is that everyone ignores the growing belly or is too polite to mention it. Even personal trainers didn't warn him to shape up. Finally, a friend took a picture to show him that he needed to lose weight. Denial of weight problems and reticence to discuss them drives obesity, especially childhood obesity. No one wants to hurt anyone's feelings so they turn a blind eye to a growing problem.

Jamie Foxx does Denzel Washington

Foxx said he emulated Washington's portrayal of different characters in mannerism, voice and preparation. And like Washington, he had to shed weight for roles.

Between "Remember the Titans" and "Training Day," Denzel had to undergo a major transformation. He went through another one for "Fences." Foxx is another chameleon actor who can drop and add weight. For "Sleepless" he had to get super thin. Men's Health showed a photo timeline of other roles that required weight fluctuations.

In "Ali" with Will Smith, Foxx weighed 220 pounds. In 2004, he gained more weight to play "Tookie" Williams (leader of the Crips gang) in "Redemption." Then Foxx had to ax almost 70 pounds in one year to play 158-lb Ray Charles.

How Jamie Foxx shed one third of himself

So how much does Foxx weigh normally? He didn't say, but it's a lot less than 200 and more than 160.

At his 5'9' height, the body mass index (BMI) says 170 pounds is overweight and 205 is obese. To get to 158 pounds from 225, Jamie had to do a period of anorexic-like fasting that enabled him to change his metabolism. He joked that after you hit your stride with exercise you can eat "a plate of beignets" and not gain weight. Are these celebrity weight loss tricks for movie roles healthy? Look at Lily Collins who got scary skinny to play a girl with anorexia. Isn't this an eating disorder in the making? Perhaps, life imitates art instead of vice-versa.