Actor Chris Pratt has clarified comments suggesting his huge weight gain in 2013 left him "impotent", confessing he used the word without knowing what it meant.

The Zero Dark Thirty star hit headlines last week (ends05Jun15) when a new interview with Men's Health was published.

Pratt showed off his muscular physique in the magazine, and in the accompanying chat, he revealed his weight ballooned to almost 300 pounds (136 kilograms) after filming 2013 comedy Delivery Man, an issue which left him unable to achieve an erection.

He said, "I was impotent, fatigued, emotionally depressed. I had real health issues that were affecting me in a major way. It's bad for your heart, your skin, your system, your spirit."

Pratt, who subsequently embarked on a health kick to star in superhero movie Guardians of the Galaxy, now admits he was wrong to claim he was "impotent", although he insists his weight gain did affect his bedroom activities.

The actor, who has a young son with wife Anna Faris, tells news show Access Hollywood, "I'm not sure I knew what 'impotent' meant when I said it. I had a lower sex drive, to be honest with you. Everything about my spirit was dull. I didn't feel great, and I think people will relate to that."

Pratt, 35, goes on to offer encouragement to others battling weight problems, claiming they, too, can overhaul their unhealthy habits with "hard work and dedication".

He adds, "To those who felt the way I felt at that time, there's really hope. You can, with hard work and dedication and just sticking to it, you can actually make a big change. And it will affect you, not just physically, not just the way you look, but how you feel and how your spirit feels and how your penis feels - especially the penis part!"