(Cover) - EN Showbiz - Matthew Fox has admitted he barely recognises himself in new film Alex Cross.

The Lost star shed 44lbs for his role as serial killer Picasso in the crime thriller, which is set for worldwide release next month.

Matthew embraced an intense workout regime to embody his character, and was left shocked by the results.

"I never watch my films while we're making them, so when the images came out on the internet, someone sent it to me," he explained to the December issue of Men's Health.

"I opened it up and was like, Holy sh*t.' I could hardly even believe it was me. But, it was exactly what I wanted to look like."

The 46-year-old believes his disturbed character is naturally slim, due to his nervous energy.

However, Matthew had to work hard and drastically adjusted his diet to achieve the body he wanted.

The star stuck to consuming chicken, steamed broccoli and protein shakes made with water during filming.

"When I read the part, it felt immediately that my character is burning energy on almost a hyper level. Without needing to spend any time in the gym he would just look like that," he marvelled.

"Almost disturbingly vascular and tendony, and f**king just... weird. That would come from an enormous amount of energy burning inside this guy. I didn't want to lose weight unhealthily, but I didn't know how to do it any other way. I read somewhere that when Christian Bale was preparing for The Machinist he ate nothing but an apple a day for months. Just one apple. That can't be good for you." (C) Cover Media