The general consensus from websites like WebMD and CBS News are the same: soda products like Diet Coke, Coke Zero, Diet Pepsi, Diet Dr. Pepper, etc., are not designed to help people lose weight. In fact, the general concern in diet soda case studies is the ability for an avid diet beverage drinker to gain more weight than a non-diet beverage drinker. Terms like "obesity" and "diabetes" start appearing in statistics concerning the equation: more diet drinks, more weight gain.
So how can drinking a no-calorie beverage really help you pack on the pounds?
While there are no proven facts that diet sodas really add weight themselves, but there are numerous studies suggesting reasons for possible weight gain. One of which is counting calories or making judgment calls. Essentially, many people allocate x amount of calories they think are acceptable to consume per day. As a result, these same people will estimate the number of calories every item they plan on eating has. The goal is to match or come close to the allocated x amount of calories they are suppose to have. Diet soda comes in as an easy way to cheat a diet because of the no calorie (no counting) bases. But what usually happens is that, because diet soda is not counted, people will not realize they are virtually over compensating those lost calories.
For instance, a person can feel good about driving through a fast food restaurant if he or she has diet soda instead of the normal soda. Their calculating tells themselves they are virtually knocking off 130 calories and should, therefore, be losing calories and weight altogether. So how come the mind games dont add up the weight gain? Basically the focus is lost -- instead of looking at portion sizes or the content of the food, people turn to diet soda as an easy fix to weight loss. Judgment is altered into thinking that a piece of pie is acceptable because diet soda can be substituted for the real thing, thus allocating more free calories to count elsewhere. Diet soda becomes the good excuse to up a portion size, whether healthy or not.
Ultimately, Jillian Michaels is right: if you want to lose weight, there is no substituting a good workout and eating right with things like diet sodas.