What a difference a break-up makes! Jason Segel looked slimmer than he has in years on the set of "Sex Tape" on Sept. 30 in Boston, where he is filming with his co-star Cameron Diaz.
The actor, who split from Michelle Williams this spring, told Us Weekly in July that he was slimming down specifically for this role. "I've just been living healthy, exercising, eating right -- no more midnight pizzas," Segel said. "This time when I take my shirt off, I've made a promise to myself, it doesn't have to be funny."
This isn't the first time the "How I Met Your Mother" star has gone through a major slim down. In 2011, he told David Letterman his assistant inspired him to lose 30 pounds after she found him asleep in a hotel in New Orleans, where he had been filming "Bad Teacher." She snapped a pic of her boss shirtless and surrounded by Taco Bell wrappers. "She took a bunch of pictures to show me what I had become," he joked, calling it his "lowest moment."
Click through to see photos of Jason's transformation ...