If you want to lose weight, one of the most effective means to do so is to cut liquid calories out of your diet. This means switching from sugary colas and juices to water. When it comes to diet drinks, sweetened with non-caloric ingredients, we’ve been quite adamant that they are problematic as well. Diet soft drinks contain controversial artificial sweeteners which may cause cancer, acclimate the taste buds to overly sweet foods, and may tinker improperly with our metabolism. That’s why we recommend staying away from diet drinks.
However, a study recently published in the journal Obesity, has concluded that diet soft drinks are not necessarily worse for weight loss compared to water. The accompanying press release was titled: Clinical Trial Affirms Diet Beverages Play Positive Role in Weight Loss for Dieters!
This took us by surprise.
The study was conducted by scientists from the University of Colorado and Temple University. Three hundred volunteers were randomly divided into 2 groups for an eating experiment that lasted 12 weeks. The test group was allowed to drink soft drinks, and the control group was allowed to drink only water. Here’s what happened:
- The people who consumed diet beverages lost an average of 13 pounds
- The control group averaged only 9 pounds of weight loss
Have we been wrong about diet drinks?
Here are some more facts for you to consider:
- The study was funded by the American Beverage Association, a trade group funded by and representing Coca Cola, PepsiCo, among other soft drink manufacturers. Read about the problem of industry funding here and here.
- Two of the study’s authors are paid consultants to the Coca Cola Company. One of them is the lead author John C. Peters. Knowing this and reading his comments on the reports takes on a different light: “This research allows dieters to feel confident that low- and no-calorie sweetened beverages can play an important and helpful role as part of an effective and comprehensive weight loss strategy.”
- The study was not blinded. The participants knew about the intervention (diet drink vs. water). In more rigid studies, the participants don’t know exactly what is being tested. The researchers knew which participants were drinking what. This lack of blinding causes unwanted biases in studies and weakens their validity.
- The study did not track caloric intake, so how are we to know that the only difference between the two groups was intake of soft drinks vs. water?
- The study lasted only 12 weeks. This is a short period of time for weight loss. It is well known that most people can lose weight over a short period of time, but what happens a year later, or 5 years later? (Note: The research team is monitoring the participants for a follow up after 12 months. It will be interesting to see what happens then.)
- People can lose weight by eating a McDonald’s Diet, but that does not necessarily bode well for their long term health. This study, due to its brevity examined just one parameter, and not the long term health effects of diet soft drink consumption as compared to water.
Unfortunately, absolute truth in science is very tricky to achieve. As it pertains to human nutrition and health, even more so. Our recommendation, whenever a study reaches a conclusion that makes no sense, is to follow the money…