Artificial Sweeteners: Are They Helping You Lose Weight or Gain it?

Danielle Pavliv, Laura Gottschalk, PhD, and Amanda Chu

When people want to treat themselves to something sweet without having to treat themselves to a larger pants size too, they often reach for low-calorie, artificial sweeteners. But do artificial sweeteners actually help you to lose weight? The answer is yes, they can. And are they safe? The answer to that is more complicated.

What are Artificial Sweeteners?

The most popular types of sugar substitutes in the US and many other countries are artificial sweeteners. Artificial sweeteners are typically made in a laboratory and don’t contain calories or supply your body with energy, vitamins, or anything else nutritious. These sweeteners are many times sweeter than sugar, so less is needed to reach the same level of sweetness as something containing sugar. Sweeteners can be used in the home for baking and cooking, and they can also be found in many processed food products including soft drinks, candy, and canned foods.

There are six types of artificial sweeteners currently approved by the FDA.

Two “natural” sugar substitutes have also been approved by the FDA. Brand names such as Truvia, PureVia, Enliten (Steviol glycosides), Nectresse, Monk Fruit in the Raw, PureLo (monk fruit extract) are all made from plants. But before being sold in the store, they must first be highly processed in a laboratory. So don’t be fooled into thinking that the word “natural” means that it comes straight from nature to your table.

Do Artificial Sweeteners Help You Lose Weight?

grocery shopping and sodaIt makes sense that eating and drinking fewer calories by switching to sugar substitutes should lead to weight loss. However, there are several studies that found that people who drink diet drinks weigh more than those who don’t [1]. People who drink diet sodas, however, may be more likely than others to be trying to keep their weight down, or they may indulge themselves by eating more high-calorie foods since they “saved calories” with their diet soda.

A better way to study if artificial sweeteners help people lose weight is known as a randomized controlled trial. People in the trial are randomly put into groups—one group uses artificial sweeteners while the other group uses sugar. Then, the two groups can be compared to see if using sweeteners resulted in a change. Randomized controlled trials show modest but significant decreases in weight, BMI, and waist size for people who switched from sugary drinks to artificially sweetened ones [2]. These studies support the idea that artificial sweeteners can help you lose weight.

Are Artificial Sweeteners Safe?

A 2020 study published in the journal Cell Metabolism by a group of Yale researchers found that the consumption of the common artificial sweetener sucralose (found in Splenda, Zerocal, Sukrana, SucraPlus) in combination with carbohydrates can turn a healthy person into one with high blood sugar. While the finding has yet to be replicated in other studies, it still raises new questions about the use of artificial sweeteners and their effects on weight gain as well as overall health.[3]

You may have heard claims that artificial sweeteners could change hormone levels [4], increase the risk of heart problems [5], and cause higher rates of type II diabetes [6]. They are also thought to have other metabolic effects, including gut microbiota perturbation. An important 2020 French study of more than 100,000 adults followed for 10 years found that people who drank a median of 6 ounces of artificially sweetened beverages per day were at higher risk for developing cardiovascular disease than people who did not consume these drinks, but consuming a median of 1.4 ounces or less did not [7]. The study also found that consuming similar amounts of sugary beverages (defined as those containing more than 5% sugar) is also associated with heart disease. More research is needed to determine if these findings are similar in other countries.

For many years, there were concerns about whether artificial sweeteners cause cancer. Studies in the 1970s showed that Saccharin (Sweet’N Low) caused bladder cancer in lab rats [8]. Since then, other studies have also shown a link between high doses of certain artificial sweeteners and cancer in rodents [9].

But, mice are not men (or women).  Experiments using mice and rats give us hints at what might happen in humans, but they’re not always correct. For example, the bladder cancer seen in the lab rats from Sweet’N Low was specific to rats because of their urine, which is different than human urine [9]. The National Cancer Institute states that no well-conducted scientific studies have shown that any of the FDA-approved artificial sweeteners cause cancer in humans.

Should you Use Artificial Sweeteners?

The Center for Science in the Public Interest (CSPI) recommends using caution with most artificial sweeteners and avoiding certain ones completely (see CSPI’s full recommendation here). We agree with CSPI that the increased risks of obesity, diabetes, and heart disease from consuming large amounts of sugary drinks may outweigh the risks posed by artificial sweeteners. However, the most obvious suggestion based on the research so far is to avoid the largest drink sizes, whether sugary or artificially sweetened. There is growing evidence that consuming even small amounts of artificially sweetened beverages may result in similar health risks to sugary drinks, even if they help with weight loss. Based on the research so far, finding healthier alternatives, such as making your own coffee or tea, or flavoring water with slices of lemon, lime, watermelon, or apple, is a good strategy for your health. And, keep in mind that you shouldn’t consume more calories in other food because you “saved” some by drinking a non-caloric drink!

All NCHR articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff. 

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.


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