In speaking with Variety, Dwayne Johnson explained the reason for his very slimmed down look that has been the talking of amongst fans.

Johnson said the reason for the weigh loss – 30 pounds of muscle per Variety, is for his next film role. He is set to portray a “whimsical, eccentric 70-something year-old” called Chicken Man in the movie “Lizard Music.” Johnson did say that he still has “a long ways to go.”
The film will reunite Johnson with “The Smashing Machine” director Benny Safdie. It was also noted this is an acting challenge Johnson saw and jumped at the chance to pull off. After the idea was pitched by Safdie to Johnson for roughly 45 minutes, Johnson said he told Safdie he is his “chicken man.”
Johnson said that he is excited at the opportunity to transform like he did with “The Smashing Machine”, which means “eating less chicken.”
According to Variety, “Lizard Music” is a film is an adaptation of a Daniel Pinkwater novel that tells the story of a septuagenarian whose best friend is a 70-year-old chicken.
Following the recent premiere of “The Smashing Machine” held at the Venice Film Festival in Venice, Italy, Johnson began cried after receiving a 15-minute standing ovation. The film is set to release in theaters nationwide in the US and Canada on October 3.
Johnson is set to begin filming “Jumanji 3″ with Kevin Hart this November.