Popular health products like Hydroxycut claim they will help you lose weight quickly, but there is little proof that it works, a Winnipeg supplement expert says.

The main stimulant in Hydroxycut is caffeine. Each pill contains the equivalent of three cups of coffee. People are supposed to take up to six pills a day.

The research used to back up Hydroxycut is not convincing to Prof. Dean Kriellaars, an expert in the field of supplements at the University of Manitoba's School of Medical Rehabilitation.

"The literature on their website I would argue to you is of a very low credibility level," said Kriellaars.

However, a spokesman for the maker of Hydroxycut backed the product.

"We genuinely have products of the highest possible quality, built on the most reliable scientific research," Vincent Scalese of Iovate Health Sciences said in a statement Thursday.

The product's website cites two eight-week studies.

On average, subjects using the main ingredients of Hydroxycut lost more weight than those using a placebo (14.99 pounds compared to 3.06 pounds in one study, and 12.54 pounds compared to 3.53 pounds in the second study).

Both groups also did 30 minutes of cardiovascular activity at a moderate rate for five days per week and followed a diet of 2,000 calories per day.

Two of the studies Kriellaars reviewed from the website were funded by the health supplement industry, which casts doubt on their trustworthiness, he said. Other studies looked at caffeine rather than the actual product or its ingredients.

The caffeine studies suggest the stimulant may raise a person's metabolic rate and help burn off more calories in a day, but there would be the same effect from drinking coffee, Kriellaars said.

Registered dietician Gina Sunderland said she gets questions about Hydroxycut all the time.

"The best thing that consumers can do is look for products that contain an NPN, which is a Natural Product Number," said Sunderland. "That means that product has been scrutinized for safety, and purity and efficacy by Health Canada."

Ads promote weight loss

Health Canada introduced regulations in 2004 that require products that make health claims to be tested and licensed. With more than 40,000 natural health products on the market and more popping up all the time, the department is experiencing a backlog.

Hydroxycut is one of the products waiting for a licence.

In the meantime, Hydroxycut is advertised on TV and websites, and in health magazines. One ad shows a man who lost 30 pounds in a month, said Kyle Bazylo of Cuts Fitness for Men in Winnipeg.

Given that Hydroxycut can cause side-effects such as jitters and a racing heart, the fitness trainer said people should start slowly and build up the dosage.