Diet sodas are common alternatives to regular sodas for those of us trying to watch our weight or decrease carbohydrates in our diet. The soda industry has long touted diet drinks as relatively healthy, low-calorie alternatives to regular soft drinks. But what effect to diet drinks have on our blood glucose and insulin levels, really?

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Many of us are trying to decrease carbohydrates in our diets. Whether you’re into “Keto”, “Paleo”, or “Mediterranean” style diets, or you are simply trying to reduce carbohydrates in general, you probably know the regular soft drinks are loaded with as much as 77 grams of sugar.

On the surface, trading regular sodas in for diet sodas seems like a good idea. They certainly have fewer calories, and that combination of  caffeine and sweetness can sometimes “hit the spot” when it comes to an afternoon pick me up.

However, a great deal of recent research has shown that diet sodas are not safer, healthier alternatives to regular soft drinks. While lower in calories, the artificial sweeteners used in these products can raise blood glucose and blood insulin levels.

In this study, Artificially Sweetened Beverages (ASB’s) were found to actually be associated with an increased risk of weight gain, diabetes, metabolic syndrome, and cardiovascular events (heart attacks and strokes). These researchers hypothesize that our bodies have “learned” that when we taste something sweet, we can “expect” some quick energy in the form of calories. When that expectation goes unmet, our bodies respond negatively with increased cravings, etc.

Another study takes a look at Non-Nutritive Sweeteners (NNS) like those used in diet drinks. Not coincidentally, the rise of these NNS over the last several decades has almost exactly parallelled the  rise in obesity in this country.

An article In The American Journal of Clinical Nutrition revealed that both sugar sweetened beverages and artificially sweetened beverages were associated with an increased risk of Type 2 Diabetes.

If diet sodas are low in calories, then how do they raise insulin and glucose levels? Glad you asked. While it’s not perfectly clear, it seems that it boils down to the fact that “you can’t fool mother nature” (or your body in this case).  As outlined above, when we experience that sweet taste, our bodies begin to anticipate a flood of quick energy in the form of glucose. When that glucose never hits the bloodstream (because the sweet taste came not from sugar but from artificial sweeteners), we actually experience MORE cravings for carbohydrates.

Insulin acts like a “key” that opens a gate on the outside of the cell to allow glucose to enter the cell.  When the gate is opened, the cell “expects” glucose or energy to come in. When glucose does not come in, the cell sends a signal to the rest of the body (including your brain), that it is low on fuel. If this sequence of events happens often enough, it can be like “the boy who cried wolf,” meaning eventually insulin loses its effectiveness in terms of it’s key-like functioning and opening the gate.

There’s a ton of physiology wrapped up in the last couple of paragraphs, but I think you can now see that diet sodas are not a great alternative when it comes to a healthy lifestyle. If you are a “Coke-a-holic”, take it one step at a time and slowly reduce your consumption of these beverages. While plain water is probably the healthiest alternative, unsweetened green or black tea can give you the caffeine kick you need without all the baggage.

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