One common suggestion when trying to lose weight is to switch from sugary sodas and juices to zero-calorie drinks, such as water and diet soda.

Do the artificial sweeteners in diet products affect weight loss? Is there any benefit to choosing "diet" products instead over plain water?

3 Answers 3


There has been a lot of debate over the topic of artificial sweeteners and weight loss. Some studies say that artificial sweeteners do promote weight loss, while others argue the complete opposite, that artificial sweeteners cause weight gain.

Do artificial sweeteners in diet products affect weight loss?

Most diet products use artificial sweeteners because they provide the sweetness of sugar without adding any extra calories. How this affects weight loss is uncertain. Several studies, both long term and short term, favor each side of the debate.

A 1988 study1 had two groups of obese men and women. Both groups were placed on the same diet, except that one group had aspartame, an artificial sweetener used in some diet products, added to the diet. Both groups also had regular exercise instruction. The men in both groups lost a significant amount of weight in the 12 week period, while the women, who also had good results, had more of a difference in the two groups, with the group whose diet was supplemented with aspartame losing about four more pounds on average. This showed that artificial sweeteners can help weight loss, but because the group was small (59), no firm conclusions could be drawn.

Another similar study2 also showed positive results in taking aspartame. In a group of 163 obese women, some of them assigned to have products with aspartame and some assigned to abstain from it, it was shown that having aspartame promoted more weight loss and allowed more weight control during a follow-up period. This study had more conclusive evidence than the previous study, but still not enough to be considered definite.

One more study3 whose results leaned towards artificial sweeteners promoting weight loss (but still inconclusive) tested beverages with aspartame or high-fructose corn syrup (which I won't talk about because it's usually not used in diet products) on normal-weight men and women. The beverages with aspartame did appear, relative to when no beverages were given, to reduce weight in male subjects, but did not have a noticeable effect on females. Once again, this leaves us with an unsatisfactory result.

As I mentioned earlier, there are some studies that say artificial sweeteners don't have any significant effect on weight or sometimes even promote weight gain.

A long-term study in San Antonio4 studied a few thousand people and asked them how often they drank beverages with artificial sweeteners. The amount of total consumption of artificial sweeteners was then estimated. About 7 or 8 years later, the subjects were re-examined and it was found that higher consumption of artificial sweeteners may be linked with a higher body mass index (BMI) and weight gain. There are many other factors that could've changed this result, and they were handled as well as they could, but still not perfectly. Because of this, the result is once again inconclusive. The study article even says, "There may be no causal relationship between [artificial sweetener] use and weight gain."

One last study5 also says that there is no evidence that artificial sweetener consumption "helps weight loss or prevents weight gain." It showed no significant link between weight loss or gain and the amount of artificial sweeteners consumed. Of course, this study has many variables that were handled as adequately as possible, but still this leads to the real result of the experiment being inconclusive.

As we can see, it is nearly impossible to tell how artificial sweeteners affect weight loss. They're not really bad for your health, so it is fine to have them. It does seem that the studies that showed weight loss from artificial sweetener consumption had a higher percentage of weight difference than the studies that showed other results. From this you may conclude that the benefits outweigh the risks. The only thing I can recommend is to have artificial sweeteners in moderation, just like anything else.

Is there any benefit to choosing "diet" products instead over plain water?

This can also be a controversial subject, but there are also studies on it. Sadly, they are inconclusive.

This study6 tested men and women with two groups, one was an artificial sweetener beverage group and the other was a water group. Both groups also took part in a behavioral weight loss treatment program. The results showed that the artificial sweetener group lost more weight on average than the water group. Still, this study was not large enough and did not have sufficient enough evidence to be considered conclusive.

Whether diet products are better than water can still depend. You can argue the same as above that the benefits of artificial beverages outweigh the risks, but you could also say that water is a safe enough choice. This is usually up to whoever is debating between diet products and water, but your doctor can be contacted if the need is really felt.

[1] An evaluation of the effect of aspartame on weight loss.

[2] The effect of aspartame as part of a multidisciplinary weight-control program on short- and long-term control of body weight

[3] Effect of drinking soda sweetened with aspartame or high-fructose corn syrup on food intake and body weight

[4] Fueling the Obesity Epidemic? Artificially Sweetened Beverage Use and Long-term Weight Gain

[5] Artificial sweetener use and one-year weight change among women

[6] The effects of water and non-nutritive sweetened beverages on weight loss during a 12-week weight loss treatment program

Harvard - Artificial Sweeteners

Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings


You should avoid products that contain artificial sweeteners because it will only promote fat storage and weight gain according to Dr. Mercola, it also promotes health problems associated with excessive sugar consumption, including Cardiovascular disease and stroke, Alzheimer's disease and artificial sweeteners stimulate appetite, increase cravings for carbs why? simply because your body are being fooled by artificial sweeteners by sweet taste but in reality, it has no calories inside. When we eat something sweet, our brain releases dopamine which activates our brain's reward center. The appetite-regulating hormone leptin that will inform your brain that you are "full" if a number of calories have been ingested. However, if we consume something that tastes sweet but doesn't contain any calories, our brain are still activated by these artificial sweeteners that we get sugar (calories), but when the sugar are not present, our body will still continue to give signal that we need more that will results in carb cravings so in short we are tricked by this artificial sweeteners. The study shows that it also worsen any insulin sensitivity and are promoting weight gain. Artificial sweeteners played a role in worsening the obesity and diabetes epidemics since their emergence in our food supply and these are added to about 6,000 different beverages, snacks, and food products, making label-reading an ever pressing necessity. Disturbingly, food industry groups are now trying to hide the presence of artificial sweeteners in certain foods.

For a safer sweetener options, I suggest using stevia or Luo Han, both of them are safe natural sweeteners. Just keep in mind however that if you struggle with hypertension, high cholesterol, diabetes, or overweight, then you have insulin sensitivity issues and would probably benefit from avoiding "ALL sweeteners".


Where I live, diet products are mostly called "light". In the US you have Diet Coke, we call it Coca Cola Light. This goes for chips (like Lays) as well. Light chips have 30% less fat. However, it turns out that the law here says that to qualify for the "light" label, the product needs to have at least 30% less for one of fat, sugar or calories. So if your favorite chips have 30% less fat, they qualify as "light". But the law doesn't say that the other two (sugar and calories) should stay as they are. So Lays is free to add more sugar to it (or salt), thus compensating for the taste loss of the removed fat. I don't know how this works for Coke, where less sugar is probably not compensated with fat.

All in all, in products where fat is replaced with sugar (and salt), I guess there is no health benefit. I would think sugar and salt is even worse than non saturated fat. This reasoning won't work for all products, but "light" and "diet" are more about marketing than about health.


Well, as I seem to get downvotes and no comments on why, it means to me that you (the downvoters) can't handle the facts. See this article on webmd about this. Apparently this applies to the US as well. A quote:

Sometimes "fat-free" is also, well, taste-free. And to make up for that, food makers tend to pour other ingredients -- especially sugar, flour, thickeners, and salt -- into the products. That can add calories.

For EU: Nutrition claims

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