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What Happens to Your Body When You Drink Diet Soda

Besides gaining no calories? Well, maybe, a lot.

A regular 12-ounce bottle of Mountain Dew soda contains 46 grams of added sugar (almost 4 tablespoons), while a diet soda contains zero grams of sugar and zero calories. So, it seems obvious that the diet Dew is the healthier choice—0 calories and sugar grams versus 46 sugar grams and 170 calories? It's lemons versus limes.

But when you ask the question "what happens to my body when I drink that diet soda," the answer isn't so straightforward. So, let's pick through the pros and cons.


Pro: You may lose weight due to the zero calories.


Drinking diet soda instead of regular versions is linked to a reduction in body weight, body mass index, and percentage of body fat, especially among the obese, according to data published in JAMA Network Open. Another study in the journal Obesity found that people who drank 24 ounces of diet soda daily for a year maintained a weight loss of up to 16 pounds.


Con: You might gain weight.

stepping on scale

A systematic review and meta-analysis in 2017 linked both sugar-sweetened and artificially sweetened beverages to weight gain. Other data suggest that non-nutritive sweeteners may stimulate appetite, leading to weight gain over time. "But much of the data is observational in nature," says medical board member and registered dietitian nutritionist Lauren Manaker, MS, RDN, LDN. "Therefore, more studies are needed before we make a definitive connection."

"Artificial sweeteners are digested differently than natural sugar," explains Justine Rosado, RDN, a registered dietitian nutritionist and certified diabetes care and education specialist with The Nutrition Queens. "What determines their metabolic fate is their complex composition, with some completely bypassing the typical absorption and digestion phases that calorie-containing foods undergo."

The bottom line is that the research is inconclusive. "Most studies show that artificial sweeteners have varying impacts on weight control, though in large part they do not cause individuals to lose or gain weight," Rosado says.

RELATED: What Added Sugar Does to Your Cholesterol


Con: Your tongue realizes it doesn't taste as good as the real-sugar version, at least at first.

Sluggish Food Sugary Soda

Artificial sweeteners like aspartame (Equal), Saccharin (Sweet'N Lo), and Sucralose (Splenda) take some getting used to. Some nonnutritive sweeteners can be 180 to 13,000 times sweeter than sugar and may change taste preferences over time, according to research in The Permanente Journal.


Pro: It may help you manage your blood sugar.

Diabetic woman taking blood sample with lancet pen at home.

"Unlike drinking regular soda that is loaded with added sugars, diet soda consumption shouldn't cause a blood sugar spike," says Manaker. People who have diabetes but like soda may find diet soda to be a good option. "Used in appropriate amounts, diet sodas are a safe way to enjoy a sweet-tasting beverage while keeping blood sugars stable," says Rosado.

RELATED: 5 Worst Foods To Eat for High Blood Sugar


Con: You may end up with weaker bones.

soda glasses

"Soft drink consumption, regardless of whether it is diet or sugar-sweetened, may have adverse effects on bone mineral density," says Manaker, author of The First Time Mom's Pregnancy Cookbook. "But the studies show mixed results; dark sodas, in particular, seem to pose the most risk." Excessive intake of phosphoric acid in sodas creates imbalances in mineral ratios that are linked to osteoporosis and fractures, according to a 2020 report in Nutrients.


Pro/Con: You may feel more energized.

sipping soda

"Many diet sodas contain caffeine, which can give people a boost when they are feeling sluggish," says Manaker. "Unfortunately, if you drink these caffeinated sodas late in the day, you may have trouble sleeping thanks to the stimulation."

Jeff Csatari
Jeff Csatari, a contributing writer for Eat This, Not That!, is responsible for editing Galvanized Media books and magazines and for advising journalism students through the Zinczenko New Media Center at Moravian University in Bethlehem, PA. Read more about Jeff
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