Diet. Sugar-Free. Zero calorie. If you’ve seen these phrases on the packages of sweet foods and drinks, it’s likely that they contained some form of artificial sweeteners. The use of artificial sweeteners in food and drink products have been on the rise due to the fact that they are a similar (and sometimes even sweeter) alternative to sugar, but do not contain any calories. Due to their prevalence, you’d think weight loss would be up, right? On the contrary, the obesity epidemic is still looking pretty grim. How could that be? Let’s investigate.
What are artificial sweeteners? They are chemicals that are not found in nature, but are manufactured in a lab to mimic sugar. However, they are different than sugar because they are digested differently, causing them to have almost no calories and not affect the blood sugar. This understandably makes them a popular alternative to people with diabetes who have to watch their blood sugar, but don’t want to give up sweets entirely. For those without diabetes, people see it as a weight loss godsend because they are able to enjoy diet or sugar-free sweets with only a fraction of the calories of the regular stuff. What could be so bad about that?
Well, that all sounds fun and nice. However, artificial sweeteners have made waves recently with suggestions that they actually make you gain weight. There is one study in which one group of mice was fed sugar-sweetened liquid while another group was fed with artificially-sweetened liquid. The two groups were then given as much food as they could eat. Scientists found that the mice who consumed the artificially-sweetened liquid eat 4 times as much food as the sugar group. In humans, a similar study composed of almost 80,000 women yielded similar results and many follow-up studies have supported these findings.
So, why is this? A simple way to explain it would to be to say that artificial sweeteners “trick” your brain into thinking you are consuming sugar. Your tongue tastes the sugar and sends a signal to the brain that you are receiving calories and energy from sugar. However, when the brain finally catches up with the body and realizes it actually didn’t receive any energy (because, remember, artificial sweeteners contain no calories), it revs up your hunger hormone ghrelin to compensate. To put it simply: artificial sweeteners make you hungrier. So, what often happens is many people drink diet sodas and eat sugar-free foods, but continue to crave more food even after eating them because of this mechanism, causing a vicious cycle.
Does this mean you should avoid artificial sweeteners at all costs when trying to lose weight? Not necessarily. As with everything, diet drinks and foods can be consumed in moderation, but you just must be careful about how much, how often and when you drink them. For example, it probably wouldn’t be a good idea to drink a diet soda right before dinner, as you will probably end up overeating. You also don’t want to be consuming artificial sweeteners day in and day out if weight loss is your goal, as you may find controlling your hunger to be much more difficult than if you only consumed diet foods every once in a while.
The bottom line? Sugar-free and diet drinks and foods do contain zero calories, and as long as you are in a calorie deficit, these artificially sweetened foods cannot directly make you lose weight. However, one of the biggest obstacles in weight loss can be controlling portions and eating only when the body needs the fuel. As it turns out, artificial sweeteners play games with your brain and manipulate your hunger cues, which may not be the best situation when trying to lose weight. Therefore, these foods are not a complete no-no and can definitely have their place every once in a while, just watch the frequency and your willpower.