Does Diet Coke Make You Retain Water?

Diet Coke may offer an easy way to satisfy your sweet tooth without overloading on sugar, but it’s not without its downsides.

Some people who drink diet soda experience uncomfortable bloating due to the carbonation. Others find they end up gaining weight rather than losing it, which is often mistaken for fluid retention, says Cleveland Clinic.

Understanding Fluid Retention

“Edema” is the medical term for swelling caused by fluid retention. This puffiness is noticed primarily in the hands, arms, feet, legs, and ankles.

The primary dietary cause of fluid retention is eating too much salty food, according to Mayo Clinic. There’s no evidence to suggest that drinking Diet Coke may be to blame.

Since some people who often drink diet soda may experience bloating or weight gain, it’s easy to mistake the swelling around their abdomen for fluid retention. While drinking diet soda presents several health concerns, increasing one’s risk of edema isn’t one of them.

What’s in Diet Coke?

Diet Coke may be a zero-calorie beverage, but that doesn’t make it a healthy drink choice.

Instead of sugar, Diet Coke is sweetened with an alternative nonnutritive sweetener called aspartame. This sweetener is approved by the U.S. Food and Drug Administration (FDA). It’s generally considered safe to consume at levels used in foods and beverages like diet soda.

While aspartame consumption isn’t linked to edema, some people may experience gastrointestinal discomfort when consuming it, notes Cleveland Clinic, including bloating, cramps, and diarrhea.

Diet Coke also contains a modest amount of caffeine, which has diuretic properties that can temporarily help reduce swelling and bloating in the body rather than cause fluid retention, explains Mayo Clinic. While not the healthiest hydration option, diet soda can contribute to your daily fluid intake goal.

As mentioned earlier, excess dietary sodium is a common culprit of edema. Diet Coke contains an insignificant 40 milligrams (mg) of sodium per 12-ounce serving, according to Coca-Cola. This isn’t enough to cause fluid retention.

The Dietary Guidelines for Americans recommends adults limit their sodium intake to fewer than 2,300 mg per day.

Finally, Diet Coke gets its signature fizziness from dissolved carbon dioxide, or carbonation. Consuming so many bubbles in a short period of time may leave you feeling bloated, but carbonation doesn’t cause fluid retention or dehydration.

Losing Weight With Diet Soda

Most research associates diet soda consumption with modest weight loss, while other studies observe no effect or even some weight gain.

According to the Harvard T.H. Chan School of Public Health, some researchers theorize the sweet flavor of drinks that don’t provide energy (calories), like diet soda, can signal to the brain it needs to eat more. However, this has yet to be proven in human studies.

Instead, experts suggest the potential for weight gain is more likely associated with the tendency to pair these beverages with high-calorie, high-fat foods, like burgers, french fries, and pizza.

To lose weight in a safe and sustainable way, consult a registered dietitian-nutritionist for help creating an eating plan that can support your specific goals.