Living with diabetes comes with many challenges; we need to constantly know what and how much we eat and drink, and continuously calibrate our medications, like metformin or insulin, accordingly. It can be exhausting. One shining beacon of light (and a delicious thirst-quencher) is diet soda. It’s sweet, it’s refreshing, and it has zero carbohydrates! But recently, more and more research has been released linking diet soda to a plethora of GI issues and health problems (including, surprisingly enough, obesity). So, what’s the deal? Is diet soda a harmless, carbohydrate freebie treat or a danger to one’s health and well-being? Read more to get the scoop.
Many people with diabetes yearn to have a refreshing beverage that won’t affect their blood sugars, and sometimes water just won’t cut it. On days when it feels as though the wind will cause hyperglycemia, nothing is crisper or more enjoyable than enjoying a diet soda – and they’re typically known as “free” food – meaning they don’t require an insulin dose, nor do they raise one’s blood sugar. Seems innocent enough, right? About 1 in 5 Americans drink at least one diet soda per day, according to the CDC, but few can figure out if they’re good or bad for us. What gives?
The Problem
Unfortunately, diet sodas are full of artificial flavors and chemicals, as well as artificial sweeteners, like aspartame and saccharin. A growing body of research links consumption with an increased incidence of type 2 diabetes, high blood pressure, obesity, dementia, stroke, and non-fatty liver disease.
On the other hand, long-term nutritional studies are notoriously unreliable. Most such studies are based on low-quality evidence, such as surveys, and even if the data is precise it’s nearly impossible to properly account for selection biases. The type of people that drink diet soda may be different in a number of ways than people who drink regular soda, or those that prefer water or coffee or juice. On the whole, no studies have proven causation between diet soda consumption and cancer.
Does Diet Soda Make You Gain Weight?
In short, no. Diet soda has zero calories and therefore does not directly lead to weight gain.
Nevertheless, studies suggest that diet soda may be related to weight gain in subtle ways, possibly by altering the other foods you eat. A 2012 study showed that the artificial sweeteners in diet soda may change the levels of dopamine in the brain, thus changing the way one’s brain responds to (and craves) sweet flavors. Artificial sweeteners can be hundreds of times sweeter than actual sugar, and if you’re used to drinking the sweet flavor of diet soda, your brain will naturally adapt, and you may start craving sweeter foods as a result. Equal (aspartame) is 160-200 times sweeter than sugar, and Sweet’n’Low (saccharin) is 300-500 times sweeter than natural sugar. This can cause you to eat more foods made with sugar, and gain weight as a result.
A more recent 2021 study proposes a similar link, arguing that diet soda may “increase food palatability through activation of the reward system and suppression of inhibitory control.”
Additionally, if you’re drinking diet soda, you may feel as though you’re doing something “healthy,” and you might make up for it by eating less healthy foods. A 2014 study showed that overweight and obese people who drank a diet soda ate between 90-200 more calories per day than those who drank sugar-sweetened soda. If you find yourself thinking that you can eat dessert or an extra-large order of fries because you only had a diet soda to drink, you may be falling prey to this phenomenon.
What Research Is Telling Us
A 2020 study from Saudi Arabia found that diet soda consumption was associated with “poor glycemic control and retinopathy.”
A 2014 study out of Japan found that men who drank diet soda were more likely to develop type 2 diabetes than those who didn’t. The study findings even controlled for age, BMI, family history of the disease, and other lifestyle factors.
A 2017 study of over 2,000 people showed that drinking one diet soda per day tripled one’s risk of stroke and Alzheimer’s disease.
A 2018 study of New Yorkers found that, while sugary soda was strongly linked to diabetes risk, switching to diet soda “may not lower the risk of diabetes, as diet soda consumption cannot be ruled out as an independent diabetes risk factor.”
Not every study finds negative effects. This 2020 study found that diet soda did not cause any changes to “fasting insulin, fasting glucose, or incident diabetes.”
Moderation Is Key
The bottom line is that diet soda is almost certainly less healthy than water, but almost certainly healthier than regular soda. Whether or not it’s a healthy option for you likely depends on your other habits and what you would otherwise be drinking.
Replacing sugar-sweetened soda with diet soda can be a remarkably easy way to cut down on sugar and calories. But don’t “treat” yourself to fast-food or sugared goodies for “being good” by having a sugar-free soda.
If you’re looking for the afternoon caffeine hit that soda normally provides, try opting for black coffee or tea to avoid the artificial sweeteners. Better yet, try weaning yourself off of soda completely and opting for a healthier, and more natural seltzer water, like La Croix, that doesn’t contain any artificial additives or chemicals.