Many dieters dream of being able to eat anything they want without gaining weight, and now a controversial new weight loss device being tested in the U.S. is promising just that.

The device, called AspireAssist, can drain up to 30 per cent of the food that a user has just eaten out of their stomach before it becomes digested.

It may sound distasteful to some, but researchers say the device is a simpler and cheaper alternative to bariatric surgery that is less invasive and fully reversible. And they say it works to help patients lose weight and keep it off.

The device consists of a tube that is inserted into the stomach, connected to a poker-chip-sized port on the outside of the abdomen. Twenty minutes after eating, the patient attaches the AspireAssist device to the port, opens a lever and sucks, or "aspirates," food out of the stomach into the toilet.

The device removes only one-third of the meal, allowing the user to still receive the calories and nutrition from the rest of the meal.

At first, users would use the device after every meal, or three times a day, but as they learned to eat more healthfully, they would reduce the frequency of aspirations.

Dr. Shelby Sullivan, the director of bariatric endoscopy at Washington University School of Medicine in St. Louis, has studied the device for a clinical trial. She says the tool forces users to change their eating habits to eat more slowly.

"In order to get good aspiration after a meal, patients have to change the way they eat. They have to chew their food really well and they have to drink a lot of water with their meal," she says.

Hampus Lager, a 28-year-old in Sweden, decided to try the device when he just couldn't lose weight using other methods.

"Because I had been trying so many years to lose, nothing had really worked even when I was working out hard and eating little food," he said.

He says the device has helped him lose 110 pounds over nine months, all while eating normally.

There are several studies underway on the device, but some obesity specialists say they have several concerns.

Dr. Yoni Freedhoff, the founder of the Bariatric Medical Institute in Ottawa, says he would like to see a lot more data on the device's safety.

"I need to know that having this procedure doesn't have long-term risks -- nutritional risks, infection risks and so forth. And until that data exists, I look at this as interesting and worthy of future study but not something I am going to be rushing people out the door to go get," he said.

The company has been selling the device in Europe for almost five years. It is now applying for approval to sell it in the U.S. and Canada as well.

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip