02/24/2012 04:59 EST

Mark Donnelly, Vancouver Canucks Anthem Singer, Talks About HCG Diet, Massive Weight Loss

Mark Donnelly, the Vancouver Canucks' anthem singer, has been looking like a new man lately.

Donnelly, who weighed more than 350 pounds, began trying a drastic diet that involves drastically cutting his caloric intake an injecting himself with human chorionic gonadotropin or HCG, reported the Vancouver Sun.

The result, the singer shed more than 170 pounds in over 18 months and now weighs in at just over 200 pounds. The paper has dramatic photos of Donnelly's weight loss.

"It was a bit embarassing to be out there on the ice with all these fine-tuned athletes and here I am lumbering out there as the carricature of the opera singer," the singer told Global News in a story about his diet.

Donnelly's voice doesn't seem to have suffered from the dramatic weight-loss and he's performed at most Canucks home games this season.

But doctors are skeptical about the diet and say it's eating less and not the shots that probably helped the singer lose weight.

"Can you lose weight on it? Of course, but that's mainly because you're hardly consuming any calories. And any benefit is not going to last," Harvard Medical School's Doctor Pieter Cohen told US News And World Report in an article about the HCG diet's risks.

The diet's proponents claim that the shots have appetite suppressing qualities. These claims are disputed by other doctors who say the shots do no such thing. In fact both the FDA and Health Canada say the shots don't work, the CBC reports.

"Every single well-done trial showed that the hCG injections were no better than injecting a salt-water placebo. In other words, people injected with hCG lost the same amount of weight as people injected with a salt-water placebo," well known health expert Dr. Oz says on his website.

Even Donnelly warned that people should "listen to their bodies" before going on drastic and experimental diets. "I don’t want people to come away thinking that I’m pushing the HCG diet, even though without it I wouldn’t have been able to do what I was able to do," he told the Vancouver Sun.