AURORA, Colo. (CBS4) – Drinking diet beverages helps people lose weight. In fact, it does a better job than water. That’s the conclusion of a groundbreaking study from University of Colorado researchers.

CBS4 Health Specialist Kathy Walsh first reported about the study when it started nearly two years ago, and now it’s got a surprising result. It’s good news for diet soda lovers who also want to drop some pounds.

This study counters the idea that diet drinks stimulate hunger. In fact, it suggests they can play an important role in weight loss as CU researchers concluded drinking diet beverages helps people lose weight.

“What we found, surprisingly, was that diet beverages actually performed better than water,” Dr. Jon Peters of the Anschutz Health and Wellness Center said.

Walsh first reported on the CU study in December 2012 when Kristi Norton was enrolled. She and about 300 others followed a diet and exercise program, but they were divided into two groups — half could drink zero-calorie beverages while the others strictly water. Norton was in the water only group.

The theory was that both groups should lose the same amount of weight since all of the drinks were calorie free. Surprisingly, that wasn’t what happened. The study found those who drank the diet beverages lost an average of 13 pounds in 12 weeks. The water drinkers lost an average of 9 pounds.

The diet drink group felt less hungry and showed greater improvement in “bad” cholesterol.

“Perhaps it helps people not have to give up that little bit of pleasure in their life when they’re otherwise trying to restrict their calories,” Peters said.

But Peters says it’s not healthy to drink a Big Gulp a day to keep the pounds away, however it does counter the notion that diet sodas stimulate hunger and contribute to obesity.

“I’d say diet sodas can be an effective tool in a weight loss program,” Peters said.

Norton said she lost 12 pounds — 3 pounds above the average, which proves there’s an over achiever in every group.

The study was funded by the American Beverage Association, but researchers were quick to point out none of its members were involved.

The takeaway is that willpower is limited because a person is already being denied calories. The finding is people don’t have to also kick the diet soda habit to drop weight.