Tuesday May 27, 2014 (foodconsumer.org) -- A study funded by the American Beverage Association and recently published in the journal Obesity claims that drinking die sodas resulted in loss of more body weight, compared with drinking no diet sodas.  But the study also shows both diet soda drinkers and non-diet soda drinkers experienced significant weight loss during 12 weeks of intervention.

For the study, 300 adults were randomized into two groups, one to drink diet sodas and the other not to be allowed to drink diet soda.  Both groups received intensive coaching on techniques for successful weight loss including recording meals they used and feedback regularly.

Dr. Jim Hill at the University of Colorado's Anschutz Health and Wellness Center and colleagues found at the end of 12 weeks of intervention, subjects in the not-to-drink-sodas group lost nine pounds per subject, compared to 13 pounds per subject found in those in the diet-soda drinking group.

Nothing in either water or diet soda promotes weight loss.  However, the group that was not allowed to drink diet soda likely ate or drank more calories than the diet soda drinkers, according to CNN, which reports the study along with many other news outlets. 

However, it’s questionable whether artificial sweeteners used in diet sodas are beneficial in a long run, Susan Swithers, professor of Purdue University was cited by CNN as saying.

Swithers and colleagues conducted a study earlier and found diet soda drinkers actually experienced the same health problems as those who drank regular sugar-loaded soda.  The common health problems include excessive weight gain, metabolic syndrome, type diabetes mellitus, and cardiovascular disease.

Prospective studies suggest those who consumed diet sodas for a longer term like 7, 10, 15 or 20 years would have much worse health outcomes, Swithers was cited as saying.

One study published this year also in the journal Obesity suggests one does not have to drink diet sodas to lose weight.  Drinking water prior to eating meals can effectively cause weight loss too because drinking water reduces intake of calories in middle-aged and older adults.   This weight loss treatment may be cheapest in the world.

Brenda M. Davy at Department of Human Nutrition, Foods and Exercise of Virginia Tech in Blacksburg, Virginia, USA and colleagues conducted the study and found premeal water drinking promotes weight loss among overweight/obese middle aged and older men and women.

For the study, 48 adults aged 55 to 75 years with body mass index of 25 to 40 kg/m2 were randomized into two groups, one group to eat a hyopcaloric diet and also drink 500 ml water prior to eating meals, and the other to receive the hypocaloric diet only for 12 weeks.

As a result, those drinking water prior to eating meals lost 2 more kg of body weight, compared with those who did not drink during the 12-week study.

The study concluded "when combined with a hypocaloric diet, consuming 500 ml water prior to each main meal leads to greater weight loss than a hypocaloric diet alone in middle-aged and older adults."

Pure water is tasteless.  A better approach for weight loss is to use some low calorie soup prior to eating calorie-loaded meal. (David Liu, PHD)