A study of about 300 adults shows that those drinking diet soda in combination with dieting actually lost more weight than those who didn't drink diet soda.

Dr. Jim Hill from the University of Colorado's Anschutz Health and Wellness Center designed the study with financial help from the American Beverage Association.

The study was designed by having one group continue to drink diet soda, while the other group would stop drinking diet soda. The study was published in the journal Obesity.

Both groups had the advantage of getting advice and guidance on dieting and meal plans.

"The results, to us, were not at all surprising," says Hill. 

In 12 weeks, the non-diet soda drinkers lost 9 pounds. In that same time period, those who continued to drink diet soda, lost 13 pounds. That's over a 44 percent increase in weight loss.

Hill says in his experience, people who have lost a lot of weight "are heavy users of noncaloric sweetners."

Those who had to quit drinking diet soda and also diet and exercise needed more willpower than those who were allowed to keep drinking diet soda. Those individuals probably ended up eating more calories to make up for it.

"It makes sense that it would have been harder for the water group to adhere to the overall diet than the (artificially-sweetened beverage) group," says Hill. 

He added, "The most likely explanation was that having access to drinks with sweet taste helps the (artificially-sweetened beverage) group to adhere better to the behavioral change program." 

This study is pleasing for those who are regular diet soda drinkers and want to go on a diet. The results show that they can continue to enjoy their diet soda without ruining the results of their diet program.

Hill does warn that diet sodas are not going to enhance your weight loss or help speed it up.

Now, a long-term study should be done according to Susan Swithers, a professor of Behavioral Neuroscience at Purdue University. 

"Doing these short-term studies that look at weight can't really tell us anything about whether or not these products are contributing to these increased risks," says Swithers. "And it's really hard to look at the (long-term) data and come up with any argument that they're helping."