Are Sugar-Free Beverages Helping You Lose Weight? Study Says No

We often associate sugary drinks like sodas with the obesity crisis, which has been plaguing the U.S. since late 1970s.

Of course, many variables are involved, but studies suggest that sugar-sweetened beverages are a prime culprit. Regular consumption of sugar-sweetened beverages like sodas, flavored waters, smoothies, sports drinks, specialty coffees, sweet tea and fruit juices have been linked to weight gain and obesity and raise the risk for serious health conditions such as type 2 diabetes, kidney diseases, gout, non-alcoholic fatty liver disease, heart disease, brain aging and tooth decay and cavities, according to the U.S. Centers for Disease Control and Prevention (CDC).    

Sugary drinks have been contributing to health issues for decades. Big Soda has tried capitalizing on these health issues by offering alternative products. For example, Royal Crown Cola’s Diet Rite was introduced in 1958, appealing to Americans who were trying to lower their calories and/or sugar intake. Since then, a wide array of soft drinks and foods are made with artificial sweeteners – an industry that grew into a nearly $5 billion business with about 40 percent of Americans as consumers.

Artificial Sweeteners

The problem is, artificial sweeteners can’t help you manage your weight – at least not long term, according to a study conducted by University of Southern California and published in Nature Metabolism.

There are eight artificial sweeteners approved by the U.S. Food and Drug Administration (FDA), according to the Mayo Clinic; they include:

• Acesulfame potassium – used in Sweet One and Sunett.
• Advantame.
• Aspartame – used in NutraSweet and Equal.
• Neotame – used in Newtame.
• Saccharin – used in Sweet'N Low.
• Sucralose- used in Splenda.
• Luo han guo – used in Monk Fruit in the Raw.
• Purified stevia leaf extracts – used in Truvia, PureVia, others.

In this new study, researchers only looked at sucralose, a common, all-purpose artificial sweetener used in baked goods, beverages, chewing gum, gelatins, frozen dairy desserts, Diet Coke with Splenda, Diet Pepsi with Splenda, Gatorade’s Propel Water, low-calorie Kool-Aid and Atkins Diet products. Sucralose is considered generally recognized as safe when consumed in moderation. But study results are mixed regarding its long-term effects.

Researchers recruited 75 subjects evenly split between male and female and weight status, i.e., healthy weight, overweight or obese. Participants had three visits. Each visit they had: 

• Baseline brain scan, blood samples and survey to determine hunger levels
• 300 ml of plain water, a drink sweetened with 75 grams of sugar and a drink sweetened with sucralose. The sugar- and sucralose-sweetened drinks were the equivalent of 16-ounce can of sugary soda.
• Follow-up brain scan, blood samples and survey to determine hunger levels several times for the following two hours

Subjects also underwent fMRI scans (or functional MRI). This type of MRI scan shows the most active areas of the brain. This helped researchers understand how regions of the brain communicate with one another.

Although the study was small, researchers were able to document the differences within and between subjects.

When participants drank the sugary drink, their hunger was dampened, and their peripheral glucose levels rose. But when they drank the non-caloric sucralose sweetened drink, activity in their hypothalamus grew by 20 percent compared to the sugary drink. The hypothalamus is the area of the brain that produces hormones that control hunger. Increased blood flow and activity correlates to increased appetite, researchers said. The sucralose sweetened drinks also caused a stronger hypothalamic reaction than plain water.

These effects were more pronounced in obese subjects. Earlier studies saw similar effects in animals.

Should You Give Up Your Diet Drinks?

It depends. How much are you consuming? Studies have found moderate amounts artificial sweeteners safe for healthy adults. They also can help manage weight when used in moderation or on a short-term basis because they help control your caloric and sugar intake.

But realize that researchers have questioned the benefits of artificial sweeteners for years. In fact, the World Health Organization issued an advisory in May 2023 warning consumers that beverages and foods with sugar substitutes is associated with weight gain because they trigger hunger.

Previous studies also link sucralose with insulin resistance and liver inflammation. Moreover, sucralose has been found to cause gut microbiome imbalances by cutting the number of good bacteria by half.

Artificial sweeteners also are much sweeter than sugar – sucralose is 600 times sweeter than sugar – which means they can affect how food and beverages taste. This is why you’re usually better off getting natural sugar from whole foods like fruits whenever possible.

If you have questions about artificial sweeteners, consult your doctor. Don’t have a primary care physician? Consider joining an MDVIP-affiliated practice. MDVIP-affiliated physicians have more time to help you in your pursuit of a healthier lifestyle. Find a physician near you and begin your partnership in health »