To lose weight, I just switched from regular soda to diet. I had heard that diet soda helps you lose weight but now someone told me it causes weight gain ... which should I believe?

-- KU, Fairfield

Although switching to diet soda saves you calories, it may also make it harder for you to lose weight.

Research on this topic is limited but some studies suggest a possible association between soda -- regular or diet -- and an increased risk of obesity and related health problems like metabolic syndrome, a condition that raises a person's risk for diabetes, heart disease and stroke.

It's easy to see how regular soda's empty calories can lead to weight-related health issues. The link between diet soda and obesity is less clear. So far, health experts are speculating that artificial sweeteners may be altering the way we regulate food intake. It's an intriguing theory based on animal studies of rats that over-ate and gained weight after feasting on zero-calorie artificial sweetness. If this holds true for humans, it may be that our bodies respond to artificial sweeteners by seeking out, or craving, calories that were promised but not delivered.

To find out if this theory applies to you, eliminate all soda and minimize artificial sweeteners in your diet for two weeks. Replace your diet soda with low-calorie beverages like: water with frozen fruit cubes; sparkling water splashed with a small amount of tangy juice like pomegranate or grapefruit; or a blend of unsweetened flavorful iced teas like peach and cranberry. After this experiment, if your appetite seems better controlled, assume that artificial sweeteners are a bad weight loss strategy. Keep in mind this experiment does not account for caffeine cravings and the fact that food cravings are usually rooted in both physiology and psychology.

While the studies I mention lack cause and effect, the take home message here is that, for many people, diet soda consumption is likely a marker for a combination of unhealthy lifestyle choices that ups risk for obesity and related diseases. For instance, someone who takes in excessive amounts of diet soda may be more likely to regularly consume other highly processed foods. Hopefully that's not you. Here's hoping you use your recent soda switch as a springboard to make further improvements in your diet!

Courtney Sansonetti, RD, CDE, CD-N, is a medical nutrition therapist and certified diabetes educator for Rehabilitation Associates Inc., 1931 Black Rock Turnpike. Direct all nutrition-related inquiries to c.sansonetti@rehabassocinc.com.