How Diet Soda May Lead To More Belly Fat In Older Adults

03/17/2015 07:10 am ET | Updated Mar 18, 2015

When given the choice between diet soda and regular soda, the calorie-free option may not be the lesser of two evils. A recent study from the Journal of the American Geriatrics Society suggests that diet soda may also lead to more belly fat, especially as you get older.

Researchers looked at data from 749 adults over the age of 65 from the San Antonio Longitudinal Study of Aging. They found that, over the course of almost 10 years, those who drank diet soda daily saw the growth of their waist circumferences more than double that of non-diet soda drinkers.

In the study, diet soda drinkers' waist circumferences expanded 2.11 centimeters over the 9.4-year period, while non-diet soda drinkers' waists only expanded 0.77 centimeters. Those who occasionally drank diet soda saw a 1.83 centimeter growth in weight circumference. Surprisingly, the researchers didn't find any consistent relationship between drinking regular soda and waist circumference. (For whatever it's worth, plenty of previous studies have had no trouble linking sugar-sweetened sodas with weight gain, though.)

Of course, the concerns associated with increasing abdominal fat extend far beyond vanity. Large waist circumference has been linked to high blood pressure, diabetes, coronary heart disease, albuminuria, depression, cognitive decline and death from cancer and cardiovascular disease, among other health risks. As you get older, you're more vulnerable to expanding waistlines and more visceral fat, the type of fat that can lead to greater health consequences since it's around important abdominal organs like the liver, pancreas and intestines.

When it comes to soda, the reason for this waist-specific weight gain and accompanying health risks can possibly be traced back to an ingredient that's found in many diet and regular sodas: phosphoric acid. According to Sharon P.G. Fowler, co-author of the study and a specialist in medicine and epidemiology at The University of Texas at San Antonio, both diet and regular sodas have comparable (if not mildly frightening) acidity levels. But people may drink more diet soda than regular soda, since the calories don't add up -- which leads to the faulty logic that diet sodas are "healthier."

But that's not necessarily the case. Sure, diet sodas don't have all the harmful sugar of regular sodas, but the phosphoric acid in them has been linked to an ever-growing list of health problems.

Fowler told The Huffington Post to try to think of your gut as your own personal rainforest, full of tiny organisms that need to stay in balance for you to remain as healthy as possible. If you're chugging diet soda because it seems consequence-free, you could be unwittingly throwing your delicate ecosystem off-kilter by ingesting copious amounts of acid.

"If a person drinks any kind of soda, whether it's diet or regular, to me it's comparable to having acid rain go down in your own private rainforest," Fowler said. "I don’t think either one is a 'healthy' alternative."

Meanwhile, the Calorie Control Council, an international association representing the low- and reduced-calorie food and beverage industry, pointed out that the study can't determine cause and effect, but only indicates a possible association between diet soda and weight gain.

Rather than deciphering the merits of diet versus regular soda, Fowler suggests you forego both. Instead, she recommended that you try drinking unsweetened beverages like coffee, tea, mineral water or 100 percent fruit juice.

Or better yet, stick to plain, old water.

Earlier on HuffPost50:

Soda Alternatives

CONVERSATIONS