As of June 2015, drinking diet soda may cause an increased risk of developing Type 2 diabetes, reports the Harvard School of Public Health. However, more research is needed to prove a definite link. Diet sodas may also promote weight gain instead of weight loss.
In 2013, the University of Minnesota published a study documenting that drinking one diet soda a day was related to a 36 percent increase in metabolic syndrome. Metabolic syndrome includes high blood pressure, elevated glucose levels, raised cholesterol levels and large waist size, reports Health Magazine. Subsequently, symptoms of metabolic syndrome put individuals at greater risk for developing heart disease, stroke and diabetes.
In addition to these findings, the University of Texas Health Science Center at San Antonio published a study in 2015 documenting the correlation of diet sodas and belly fat, reports Forbes Magazine. According to the study, people over 65 years of age who drank at least one diet soda per day reported an average increase in waist size of 3.16 inches over the span of 10 years.
Although the long-term effects of diet soda are still being debated, there are no health benefits associated with artificially sweetened beverages, claims Today. Today based its claims on a 2013 report published in the medical journal "Trends in Endocrinology and Metabolism."