A recent review of the research surrounding diet beverage consumption shows that the more you drink, the greater your potential changes for gaining weight.
In theory, diet beverage consumption should lead to weight loss if it replaces a higher-calorie drink. Swapping one can of Coke for one can of Diet Coke each day with no other changes should lead to a ten pound weight loss per year. Unfortunately, other things usually do change and that’s why theory does not always translate into practice. (Remember, in theory socialism and Communism aren’t too bad either).
So what’s the disconnect between theory and practice? Two main points:
1. According to Yang, “Increasing evidence suggests that artificial sweeteners do not activate the food reward pathways in the same fashion as natural sweeteners…Sweetness decoupled from caloric content offers partial, but not complete, activation of the food reward pathways. Activation of the hedonic component may contribute to increased appetite. Animals seek food to satisfy the inherent craving for sweetness, even in the absence of energy need. Lack of complete satisfaction, likely because of the failure to activate the post-ingestive component, further fuels the food seeking behavior. Reduction in reward response may contribute to obesity.”
Interpretation: When we drink diet beverages, our body has been primed to have something sweet, but it did not get the calories associated with the sweetness (since diet soda has zero calories). This creates a disconnect between our brain and body, so we now look to eat something to satisfy this newly created un-fulfilled calorie craving. So by not having the calories in the soda, we look for something else to make up those calories…and if that food is high in calories, then we may have just been better off having a regular, 120 calorie can of soda. (Of course, the best option is water or another low-calorie beverage without artificial sweeteners to avoid the calories and the cravings).
2. According to Yang, “Lastly, artificial sweeteners, precisely because they are sweet, encourage sugar craving and sugar dependence. Repeated exposure trains flavor preference. A strong correlation exists between a person’s customary intake of a flavor and his preferred intensity for that flavor. Systematic reduction of dietary salt or fat without any flavorful substitution over the course of several weeks led to a preference for lower levels of those nutrients in the research subjects. In light of these findings, a similar approach might be used to reduce sugar intake. Un-sweetening the world’s diet may be the key to reversing the obesity epidemic.
Interpretation: These extremely sweet artificial sweeteners blunt our body’s ability to detect and become satisfied from the natural sugars found n unprocessed foods like fruit, dairy, etc. Therefore we need to add more and more sugar (and calories) to our foods to become satisfied. We become “sweet” addicts.
If you don’t believe me, try this: next time you are hungry and haven’t had any sweet foods or beverages in a while, go buy a piece of fruit (apple, peach, etc.) and a sweet beverage (soda, diet soda, etc.). Eat half of the fruit and feel how sweet it tastes. Then drink the entire soda or diet beverage (you don’t have to pound it down). Now eat the other half of the fruit and note how much sweetness you get (I’m willing to bet it will be much less). If it’s not as sweet, is it as satisfying? Or would you rather look for something sweeter (and more highly caloric) to eat?
Lesson Learned: We must slowly reduce our “sweet” consumption (from regular or diet beverages, sugary foods, etc.) over time. If you try to go cold turkey, your body will likely rebel at some point (think about any time you tried to cut out sugar all at once). Have one less sweet drink or snack for a few weeks until you get used to it. Then go down by another one. Take your time. Life is a marathon, not a sprint.