You’ve made a New Year’s resolution to lose weight in 2013, but should you favor zero-calorie drinks or water as part of your diet? Or does it matter at all which of these beverages you choose for weight loss?

That’s what researchers at Temple University’s Center for Obesity Research and Education (CORE) and the University of Colorado’s Anschutz Health and Wellness Center are hoping to discover as part of a year-long study comparing the effects of zero-calorie drinks and water in the context of weight loss. The Food and Drug Administration defines zero-calorie drinks as those having five or fewer calories per eight-ounce serving.

Water has long been the recommended beverage in any weight loss/maintenance program, yet dieters frequently turn to the more flavorful diet or zero-calorie beverages as a replacement.

“Since both of these drinks are calorie neutral, you should be able to lose the same amount of weight regardless of whether you consume zero-calorie drinks or water while dieting,” said Stephanie Vander Veur, program director for clinical research at CORE. “On the other hand, some think that non-nutritive sweetened beverages may increase a person’s preference for a sweet taste that may lead them to consume additional calories. No one has really tested this to date.”

Temple is seeking to recruit up to 150 people to take part in the study, which is being led by CORE Director Gary Foster. The first Temple group of 18 already began participating in the study in November. The University of Colorado will also study 150 participants.

Those who are selected to participate must be regular consumers of zero-calorie or diet beverages (currently consume a minimum of three per week) and above ideal body weight. They will participate in a weekly 60-minute group weight loss program during the first 12 weeks of the study and then 10 monthly 60-minute group weight loss/maintenance meetings thereafter.

Participants will be required to drink a minimum of 24 ounces per day of either a zero-calorie beverage that includes a non-nutritive sweetener — such as Diet Coke, Coke Zero, Diet Pepsi, Pepsi Max, diet ginger ale, diet Snapple, and Vitaminwater zero — or water, depending on which study group they are randomly assigned. Those who are in the water group will not be able to drink any zero-calorie beverages, and must also refrain from using non-nutritive sweeteners in other drinks such as coffee or tea. Foods that contain non-nutritive sweeteners are permitted.

The study will be conducted at CORE, located on Temple’s Health Sciences Campus in North Philadelphia, Jeanes Hospital in Northeast Philadelphia and Temple’s Center City campus.

The study is being funded by the American Beverage Association.

Anyone from the Philadelphia region interested in participating in the study should contact Temple’s Center for Obesity Research and Education at 215-707-3292.