Is Diet Soda Worse Than Regular Soda? Doctors Reveal the Better Choice for Weight, Diabetes and More
Discover the smarter sip based on your health goals
Key Takeaways
- Diet soda has a bad rep, but it has some advantages over sugar-sweetened soda.
- Regular soda poses bigger diabetes and liver risks, but may be better for mental wellbeing.
- Unsweetened flavored sparkling water is a healthy swap for both regular and diet soda.
The crack of the can, the hiss of bubbles, the icy-cold sweetness: So many of us delight in our daily Diet Coke break—and that’s true even though sugar-free beverages are now seen as so addictive and unhealthy, they’ve been dubbed “fridge cigarettes” (a phrase recently added to the Merriam-Webster slang dictionary!). But is diet soda worse than regular soda—or does it just have a worse reputation?
To find out, we turned to scientific studies and Chicago-based internal medicine expert Francesco Bajani, MD. And the answer turned out to be different depending on our individual goals. Dr. Bajani helped us break down the benefits and risks of diet soda vs. regular based on health issues women over 50 care about most.
Diet soda vs. regular: 6 battles, 6 surprising outcomes
Whether you love Diet Coke, Coke Zero, classic Coke or another soft drink altogether, keep reading to see how your favorite fares in can-to-can combat…
Woman's World Answers
Round 1: The best soda for weight loss
Winner: Diet soda by a nose. Sugar-sweetened drinks add calories that don’t make us full and that may actually stimulate hunger. It’s also well documented that added sugars wreak havoc on our metabolic health. So it’s no surprise large studies consistently link sugary drinks to weight gain, says Dr. Bajani, founder of the telehealth platform Checkup MD.
Research on diet soda is mixed. Artificial sweeteners seem to have a negative impact on appetite control mechanisms, and a University of Texas study found that the more diet soda older adults drank, the more belly fat they had. Yet drinking diet soda can satisfy the urge for something sweet with no calories, an advantage for many. During a year-long University of Colorado study, diet-program participants allowed sugar-free soft drinks lost three times more weight than those only allowed water. This led the research team to declare diet soda “superior for weight loss and maintenance.”
Round 2: The best soda for mental wellbeing
Winner: Regular soda by a nose. A large NIH-funded study of 263,925 adults found that people who drank 4+ cans of regular soda per day were 22 percent more likely to develop depression while those who drank 4+ cans of diet soda a day were 31 percent more likely to become depressed. The theory is that both cause changes to gut bacteria that may lead to brain inflammation, but compounds in artificial sweeteners are also linked to disrupted production of the feel-good hormone serotonin.
Round 3: The best soda for diabetes prevention and control
Winner: Diet soda. Regular soda “delivers a rapid liquid sugar load” that is perhaps the single biggest driver of the diabetes epidemic, says Dr. Bajani. A major BMJ meta-analysis found that each additional daily serving of a sugary drink raised type 2 diabetes risk by 18 percent.
Is diet soda a perfect alternative? No. Artificial sweeteners may alter gut bacteria in ways that undermine blood sugar control, and the BMJ analysis found that each additional serving of diet soda a day raises diabetes risk by about 8 percent. “For someone with diabetes or prediabetes, I would recommend reducing both regular and diet soda and moving toward unsweetened drinks,” says Dr. Bajani.
Round 4: The best soda for a healthy liver
Winner: Diet soda. Most research—including the famous Framingham Heart Study—have found that sugar-sweetened beverages are associated with fatty liver disease, while diet soda is not. Why? Sugary drinks deliver “a fast, heavy dose of fructose straight to the liver,” says Dr. Bajani. Unless you’re very active, the liver will convert a lot of that fructose to fat. And if the organ is overloaded and can’t push fat out fast enough, it basically hardens and gets stuck. It’s how so many of us end up with a fatty liver, increasing risk of diabetes, heart disease and host of other issues, says Dr. Bajani.
More recent European data complicates the picture slightly for diet drinks. “I wouldn’t say diet soda is a liver-healthy beverage, but it’s likely better than regular soda here,” says Dr. Bajani.
Round 5: The best soda for heart health
Winner: None. Regular soda has been shown to harm the heart through well-established pathways like weight gain, insulin resistance, higher triglycerides, elevated blood pressure and inflammation, cautions Dr. Bajani. It can have a serious impact your long-term health.
Meanwhile, Women’s Health Initiative data on over 81,000 older women found that high diet soda consumption was associated with 23 percent higher risk of stroke and 29 percent higher risk of heart disease. The explanation? Preliminary University at Buffalo evidence suggests artificial sweeteners might directly damage the lining of blood vessels.
Says Dr. Bajani: “High diet soda intake—especially two or more per day—should not be considered heart-healthy. For heart health, both should be limited.”
Round 6: The best soda for bone health
Winner: None. This is the one category where diet and regular cola are equally problematic, since the culprit isn’t sugar or artificial sweetener—it’s bone-weakening phosphoric acid, which is in both types of soda. The Framingham Osteoporosis Study found that cola intake, regardless of type, was associated with lower bone mineral density in older women. If you do drink soda, be sure you’re also getting plenty of bone-boosting calcium and protein in your diet, says Dr. Bajani.
So is diet soda worse than regular? The bottom line
Across most categories, diet soda isn’t worse than regular soda—and in several, it’s meaningfully less harmful. Dr. Bajani adds that most concerning findings on diet soda come from observational studies that don’t firmly establish diet soda as the culprit, while there’s direct evidence of the harmful effects of sugar-sweetened beverages. Of course, as you’ve probably realized while reading this story, neither drink is a particularly healthy choice, especially if you’re consuming it in large amounts.
Dr. Bajani’s advice: Enjoy your favorite soda—diet or regular—as a semi-occasional indulgence, and the impact on your health should be minimal. And if you don’t want to give up the ritual of your daily soda break, aim to transition to an unsweetened flavored sparkling water instead. That’s a trade we can absolutely get behind.
Conversation
All comments are subject to our Community Guidelines. Woman's World does not endorse the opinions and views shared by our readers in our comment sections. Our comments section is a place where readers can engage in healthy, productive, lively, and respectful discussions. Offensive language, hate speech, personal attacks, and/or defamatory statements are not permitted. Advertising or spam is also prohibited.
