Los Angeles, Dec 1 (IANS): Actor Matthew McConaughey has lost about 18 kg for a movie role, and despite the drastic weightloss he says he is "as healthy as can be".

He has lost pounds to play a skeletal AIDS victim in his latest movie "The Dallas Buyer's Club", and his lean frame is giving fans some cause for concern.

However, McConaughey insists his extreme dieting isn't taking a toll on his health as he is relying on a healthy diet of fish to keep his energy levels up, reports dailystar.co.uk.

"I feel fine. I really do. I'm eating fresh fish. I'm just eating small amounts. I'm not being starved. If anything, it's as much a spiritual journey as it is physical. I have body soreness. (But) I'm as healthy as can be. My blood pressure, everything's fine," he told TheDailyBeast.com.

The "Magic Mike" star had earlier said he will indulge in a greasy cheeseburger once filming on the drama ends, but he now accepts he won't be able to do so straight away, especially after dieting so much.

"You can't just start eating cheeseburgers and ice cream. Your body will go into shock," he said.