Doctors Urge Moderation After Reports of Heavy Diet Soda Use; Experts Detail Potential Risks
Nutrition and medical specialists say occasional diet soda is generally safe, but heavy daily consumption has been linked to metabolic, vascular and dental harms.
Health experts are urging moderation in diet soda consumption after publicity around heavy use of artificially sweetened beverages. While diet sodas contain few or no calories, clinicians warned that drinking multiple cans daily has been associated with higher risks of type 2 diabetes, heart disease, stroke and other health concerns.
The conversation resurfaced after a high-profile admission by musician Fat Joe that he sometimes drank dozens of cans of Diet Pepsi in a single day, prompting questions about how much diet soda is too much. Registered dietitians and physicians said the sweeteners used in these beverages, while approved for use, can have biological effects when consumed frequently and in large amounts.
Artificial sweeteners in diet sodas include lab-made compounds such as aspartame, sucralose, saccharin and acesulfame potassium, as well as plant-derived alternatives like stevia and monk fruit. Vanessa Rissetto, a registered dietitian and CEO of Culina Health, said the sweeteners "vary in sweetness intensity, which is why only tiny amounts are used," and that plant-based options may be perceived as "more natural" and could have a smaller impact on the gut microbiome.
"They're all considered safe in normal amounts," Rissetto said. But safety in regulated doses does not eliminate potential downstream effects of heavy, chronic intake, according to clinicians interviewed.
Physicians point to several mechanisms by which artificial sweeteners and other soda components may influence health. Dr. Adam Perlman, chief medical officer at Pendulum Therapeutics, said certain sweeteners have been linked to changes in gut bacteria that could affect how the body manages blood sugar. Rissetto said sweet taste receptors can prime the body to expect calories, and when energy does not arrive, that mismatch can diminish insulin sensitivity over time.
Alterations in glucose handling and gut microbial composition may contribute to systemic inflammation and impaired glucose metabolism, both of which are risk factors for type 2 diabetes. Rissetto said hormonal and metabolic changes tied to high intake of diet soda could raise triglyceride levels, lower high-density lipoprotein (HDL) cholesterol and lead to endothelial dysfunction — damage to blood vessel linings that can raise blood pressure and atherosclerosis risk.
Those vascular effects, clinicians said, help explain why observational studies have associated frequent diet soda consumption with higher rates of heart disease and stroke. Experts noted that most large studies show associations and do not prove causation, but they cautioned that the biological pathways are plausible and merit attention.
Beyond metabolic and vascular concerns, regular intake of highly acidic beverages, including diet sodas, can erode tooth enamel. Caffeine in many diet sodas can cause jitters, headaches or sleep problems for some people. Carbonation and certain sweeteners may also cause bloating or stomach discomfort in sensitive individuals.
There is also evidence that artificially sweetened drinks can influence appetite and food choices. Rissetto said tasting sweetness without accompanying calories can increase hunger signals and drive people to consume more food, particularly sugary or high-carbohydrate items, through mechanisms tied to both reward pathways and unmet expectations of energy intake.
Experts offered practical guidance for consumers. Rissetto said diet soda should be treated as an occasional drink rather than a primary source of hydration. "One a day is fine for most people, but a few a week is even better," she said, recommending rotation with water, sparkling water or unsweetened beverages. Perlman echoed the need for moderation, noting that "over time, high intake may be linked to weight gain, heart problems and blood sugar issues."
Regulatory agencies have deemed commonly used artificial sweeteners safe at established intake levels, and for many people moderate consumption of diet soda is unlikely to cause acute harm. However, clinicians and nutritionists stress that drinking extremely large amounts over an extended period — for example, dozens of cans per day as reported in some personal accounts — raises potential health concerns and warrants caution.
Where possible, health professionals recommend prioritizing plain water and other unsweetened drinks for regular hydration and reserving artificially sweetened beverages for occasional consumption. Individuals with specific health conditions, such as diabetes or cardiovascular disease, should consult their clinicians about how diet sodas fit into their overall dietary plans.