Matthew McConaughey weighs 143 lbs after he lost almost a quarter of his body weight

Matthew McConaughey has revealed he is now down to his goal weight to play the real-life AIDS-afflicted character of Ron Woodroof in The Dallas Buyers Club – and doesn’t plan on losing any more.

In a new interview the 6 ft-tall actor reveals he now weighs in at 143lbs – having lost 38 lbs over the past few months (more than the 30 lbs previously reported).

With a BMI (Body Mass Index) of 19.4, Matthew McConaughey is still in the “normal weight” range – but skirting very close to and just seven pounds away from the underweight range (below 18.5).

Matthew McConaughey, 43, opened up to HitFix.com about the struggle he endured to shrink his frame – admitting it has been “90 per cent diet”, and exercise less so, which has seen him transform into the gaunt figure he is today.

He also admitted to looking forward to being able to eat a cheeseburger – but before then he has to maintain his weight for the next five weeks while filming after arriving on location in New Orleans over the weekend.

“I feel good, now,” Matthew McConaughey told HitFix‘s Gregory Ellwood. “Overall, probably got 35 percent less energy. The tough part, there have been plateaus.”

He explained: “Getting past 170 [lbs] was really hard, but then once you get into the 167, the next 7 come off easy. Getting past 160, really hard. But then you fly down to 150.

“Getting past 150 was really hard. And then, bam, got down to 143 and that’s where I want to be. Once you get past the plateau, the body seems to understand, <<OK this is where we’re living now, this is where we are>>, so the energy rises.”

Matthew McConaughey also talked about how he realized it was his diet he needed to regulate most – rather than his exercise.

The star is sticking to a drastic regime of cardio, five ounces of protein a day and low carbohydrates to maintain his emaciated form.

He said: “I’m doing cardio but I’ll tell you what, the more I’ve learned is – and I think it comes with age too – is it’s 90 percent diet.

“It’s 90 percent amount and then what you’re eating because right now I’m not losing any more weight if I burn 1,500 calories, two hours of cardio in an afternoon, or if I don’t. It doesn’t matter. It’s a matter of how much I eat or how little I eat.”

Matthew McConaughey says he has had to be strict on himself and stay away from temptation – but concedes that while he is looking forward to eating normally again, his body will probably be in for a shock.

“The organs shrink, so my stomach has shrunk as well. So as much as I can’t wait to have that cheeseburger, on the day, it’ll be damn hard to eat the whole thing.”

But for now: “I choose to pick my places where there’s less good smells and temptations. I don’t want to be doing this interview at a Pizza Hut buffet,” he added with a laugh.

The gritty film role, which initially attracted Brad Pitt and Ryan Gosling, revolves around Ron Woodroof, the heterosexual, homophobic electrician who died of the disease in 1992 after illegally smuggling HIV drugs not approved in the States.

This is perhaps Matthew McConaughey’s most dramatic turn, having last appeared as a sexy stripper in Magic Mike.

Jennifer Garner has joined the film as Dr. Eve Saks and Jared Leto has also come on board to portray Ron Woodroof’s friend Rayon, a flamboyant HIV-positive cross-dressing hospital patient.