Diet Soda and Waist Circumference

Research on diet soda and aspartame presented at the American Diabetes Association's 71st Scientific Sessions from June 24-28 in San Diego have sparked a lot of media attention.
As Science Daily summarizes:


ScienceDaily (2011-06-28) -- In the constant battle to lose inches or at least stay the same, we reach for the diet soda. Two studies suggest this might be self-defeating behavior. Epidemiologists report data showing that diet soft drink consumption is associated with increased waist circumference in humans, and a second study that found aspartame raised fasting glucose (blood sugar) in diabetes-prone mice.


The study presented by researchers at the University of Texas Health and Science Center at San Antonio looked at the relationship between drinking diet soft drinks and long-term change in waist circumference in 474 participants, aged 65-74 yrs at baseline, in the San Antonio Longitudinal Study of Aging (SALSA). They found that over the 9.5 year study average increases in waist circumference of people drinking two or more diet soft drinks a day were five times larger than people that did not drink diet soft drinks.
Here is the graph posted at the American Diabetes Association website:

http://ww2.aievolution.com/ada1101/index.cfm?do=abs.viewAbs&abs=10061


I could not find this research in a published peer reviewed journal  and did not attend the conference so was not able to look at  the details of the study such as how diet soft drinks are defined e.g. is it only sodas or other drinks with artificial sweeteners? It is a very interesting study and gives one a lot to think about.  Notice the age range is 65- 74 at baseline would the results be different in a younger group? What about waist circumference among regular soft drink users? There is some interesting research into artificial sweeteners and blood sugar too, but that is for another post.
I did come across another study by the same authors looking at the same group in the San Antonio Longitudinal Study of Aging (SALSA) observed a connection ( they did not state it cause and effect) between artificial sweetener use and increase BMI over the 7 to 8 year study period. This study did not distinguish between type of artificial sweetener and did not include fruit flavored drinks/powders/mixes.


The article was published in the journal Obesity in 2008 and the full text is free at www.nature.com