Study Suggests Low-Calorie Fizzy Drinks Increase Waist Size in Over-65s

Low-calorie fizzy drinks are often reached for as an alternative to their sugary counterparts, by those aiming to maintain a healthy weight or shed a few pounds. However, a US study has found consumption of diet sodas to be associated with the opposite effect in the over-65 age group – a larger waist.

Effects of Diet Drinks in Older Adults

Scientists at the University of Texas followed 749 participants, all over the age of 65, for ten years. They observed their diet, and tracked their weight and waist size. They found that those who drank low-calorie fizzy drinks daily saw their waist size increase by an average of 3.16 inches, compared to 1.83 inches for those who only drank the diet drinks occasionally, and 0.80 inches for those who did not drink them at all.

“The study shows that increasing diet soda intake was associated with escalating abdominal obesity, which may increase cardiometabolic risk in older adults,” says lead author Sharon Fowler, of the Texas University health science centre.

An accumulation of fat around the middle can be a cause for concern because it is close to the body’s vital organs and can produce dangerous chemicals. A larger waist has been linked to heart problems and type 2 diabetes.

“Our study seeks to fill the age gap by exploring the adverse health effects of diet soda intake in individuals 65 years of age or older,” says Fowler. “The burden of metabolic syndrome and cardiovascular disease, along with healthcare costs, is great in the ever-increasing senior population.”

Criticisms of the Study

While Fowler and her co-researchers are confident that their evidence displays a link between diet drinks and waist size, other experts have highlighted flaws in the study and declared the results unreliable.

“These findings are not yet ready for translation into public health messages, as this study does not establish that diet soda leads to accumulation of abdominal fat, due to current study limitations,” says Dr Nita Forouhi of the University of Cambridge. “These include lack of accounting for other dietary habits or total calorie intake, and issues of ‘reverse causation’ as the consumption of diet sodas was relatively higher among those who were overweight or obese.”

Gavin Partington, director general of the British Soft Drinks Association says that the study “does not and cannot establish causation” and that “the body of evidence accords with common sense, that diet soft drinks can help to reduce calorie intake.”