Dispelling nutrition myths, ranting, and occasionally, raving


Popping the bubble: Are diet sodas making us fat?

A fellow dietitian recently sent me a link to the latest release from Hungry for Change in the hopes that I would be prompted to rant as a result. Fortunately, she was correct. This release features Dr. Mercola criticizing diet sodas and blaming them for making us fat, among other things. To begin with I’d just like to say that I’m no big fan of sodas, diet or not, and I’m always going to be a proponent of whole, natural foods. However, I know that many people are lovers of pop and for those who are trying to lose weight or reduce sugar consumption, diet sodas can be a reasonable replacement or tool to assist in weaning them from pop entirely.

The first thing that I did after receiving the above link was to look-up Dr. Mercola on QuackWatch. Not only is he making huge profits from a line of supplements, he has also been ordered by the FDA to stop illegal claims. What were these claims? They were unsubstantiated claims regarding the benefits of some of the products he sells. In addition to this issue, he has made other unfounded claims such as: opposing immunization, fluoridation, and mammography. Not to mention that he’s received a boost in sales and popularity from being repeatedly featured on the Dr. Oz Show, and we all know how credible that doc is.

So, we know that the guy making all the claims is a quack, but it’s still possible that there’s some validity to the claims about diet soda (I’m trying to give the benefit of the doubt!). The basic argument is that because diet soda drinkers waistlines are rapidly expanding this must be due to the diet soda. The problem with this assertion is that there are many confounding variables that could be causing this increase in waist size. For instance, diet soda drinkers are likely consuming diet soda because they are struggling with weight issues to begin with. There is no way that cause and effect can be determined from observation. It was thought that the consumption of non-nutritive sweeteners caused our bodies to crave true caloric sweets, and this is the argument made by Mercola. However, more recent research (1, 2) has disputed this finding and shown that there is no link between diet soda and increased appetite.

While I am not a fan of pop and artificial sweeteners I am even less of a fan of unsubstantiated health claims. Curbing the obesity epidemic is not going to be achieved through the elimination of diet sodas. No one simple change to our diets is going to “cure” obesity, even if diet soda was the culprit Hungry for Change and Dr. Mercola would have you believe. I’ve said it before, and I’m sure I’ll say it again: obesity is not a result of individual choices it’s a result of our current environment.