It’s sweet, refreshing, and zero-calorie, but many say this beverage is bad for your body. What’s the real story?
“Diet soda can’t be good for you.”
Maybe you’ve heard this before. (Or said it yourself.)
After all, diet soda offers no vitamins or antioxidants, and it’s usually artificially sweetened. So what, exactly, is “good” about it?
While that argument sounds logical, it doesn’t answer the real question on everyone’s mind:
Is diet soda actually bad for you?
And of related interest: Should you stop drinking diet soda?
To find out, I examined the body of research and along the way, I asked lots of questions, including:
- Does diet soda lead to weight gain?
- Can it make you crave sugar?
- Does it affect your hormones?
- Can it mess with your microbiome?
- Does it cause cancer?
Plus: Why are some people so “addicted” to it?
The answers, found below, can help you decide if diet soda is right for you.
Does diet soda lead to weight gain?
Over the last two decades, several large observational studies have suggested a link between diet soda consumption and being overweight or obese. (Other studies have shown benefits for weight control)
If you’re not familiar with the term “high-intensity sweeteners, it’s the trendy way food scientists categorize zero- and very-low-calorie sugar substitutes.
These substitutes include artificial sweeteners—like aspartame—and all-natural sweeteners, such as stevia.
There are eight high-intensity sweeteners approved for use in food by the United States’ Federal Drug Administration (FDA):
- Acesulfame Potassium
- Steviol Glycosides (stevia)
- Monk Fruit Extract (luo han guo)
While high-intensity sweeteners are used in thousands of food products, they’ve become notorious as a key ingredient in diet soda.
Theory 1: Diet soda makes you addicted to sugar
The idea: Sweet foods and beverages alter your taste preference, so you crave more sweet foods. That, in turn, could make it more difficult to turn down dessert or break-room doughnuts.
It’s well-established that consuming sugar-sweetened foods can increase your desire for sweets. You tend to crave whatever you eat habitually, and this seems to be true for both sugary and non-sugary foods.
But does consuming high-intensity sweeteners, specifically, make you want sweets? The research isn’t clear.
Most studies that suggest high-intensity sweeteners increase the desire for sweet foods have been done on rats. In fact, in a 2019 meta-analysis published in the British Medical Journal, researchers found just two randomized controlled trials that tackled the question of sweet preference head-on in humans. And they did it by adding aspartame to the diets of overweight and obese subjects.
The conclusion of those studies: Among those who consumed the high-intensity sweetener, the desire to eat sweet foods was slightly lower.
“There’s some evidence that consuming a diet version of a sweet food can actually help satisfy your desire for sweets. Especially if you’re used to consuming a sugary soda and replace it with a diet drink.”
There’s also this possibility: The effect could be highly individual. Perhaps this is a problem for some but not for others.
Theory 2: Diet soda affects your hormones
The proposed mechanism here: High-intensity sweeteners “trick” your body into thinking you’re eating sugar. This triggers your pancreas to release the hormone insulin, which signals your body to slow the breakdown of fat. As a result, it could be harder to lose weight.
A small insulin bump has been observed in studies on sucralose and saccharin, but one study of 15 young men failed to find the response for aspartame. Overall, human studies show these insulin spikes are so small they’re hard to detect and very short-lived. Which makes it unlikely they impact weight loss at all, given what we know now.
Plus, even if there were a significant insulin release, your ability to lose weight is most dependent on your overall energy balance, not insulin.
Theory 3: Diet soda disrupts your micro biome
What if high-intensity sweeteners alter your microbiome? “That could have implications for energy balance, appetite, immune function—all kinds of things.
As with other issues, its believed any impact could be dependent on the type of sweetener used. Those that make their way to your colon, for instance—such as stevia, sucralose, and to some extent, saccharin—might be more likely to present problems.
Of course, these aren’t the only ways a no-calorie diet soda could lead to weight gain. Some studies have suggested that consuming high-intensity sweeteners may increase hunger, by perhaps interfering with appetite hormones and how your brain regulates food intake (or by some other mechanism). But even more studies have shown no effect at all.
“The idea that high-intensity sweeteners increase hunger seems to only be true if they’re consumed alone, in the absence of other nutrients, this doesn’t, however, seem to be the case when they’re consumed with meals.
What about cancer and other serious health problems?
In the 1970s, saccharin was linked to bladder tumors in rats. For a while, the sweetener was even banned from foods and beverages in the U.S.
But the cancer link never emerged in humans, and as a paper from Current Oncology notes, you’d have to drink 800 cans of diet soda per day to reach the dose used to induce cancer in rats.
Still, the cancer scare means that every high-intensity sweetener since saccharin has faced increased scrutiny.
“There are still people out there who claim that [high-intensity sweeteners] are associated with cancers,but every governmental body that has reviewed them concludes that when used in reasonable amounts, they’re not harmful.”
But keep in mind: High-intensity sweeteners are used in far more than diet soda. You’ll find them low-calorie yogurts, energy drinks, baked goods, diet desserts, and protein powders and bars.
And just because you’re under that limit for diet soda doesn’t mean you’re drinking what most health experts would consider “reasonable amounts.”
Why can’t you stop drinking diet soda?
If you’re a diet soda diehard, maybe you’ve wondered why you can’t get enough. Plenty of people even say it’s downright “addictive.”
You can be sure: That’s no accident.
Food and beverage manufacturers scientifically engineer products, including diet soda, to appeal to the pleasure centers in your brain, belly, and mouth, that drives you to consume more of it than you might otherwise.”
The sweetness is no doubt part of diet soda’s allure. But the other big factors? Carbonation, caffeine, and flavor enhancers.
All combined, this is known as stimuli stacking, It’s how companies engineer foods and drinks to make them nearly irresistible.
The weird reason you love carbonation
Ironically, the appeal of carbonation is that it hurts: The CO2 burns your tongue. Like the Tabasco on your eggs, the pain is mild and enjoyable. It also occurs through an entirely different pathway.
Enzymes in your mouth convert CO2 into carbonic acid,,That can actually acidify the tissue, so it will hurt a little bit.”
The pain increases as the bubbles sit on your tongue, and that creates a built-in customization mechanism. Someone who likes more of this pain can simply savor each sip longer.
In addition to the mouth thrill of a minor burn, carbonation amplifies the signal coming from the liquid, so it quenches your thirst better than flat water.
The likely reason: It provides more sensory data for your brain to latch onto. This can make a diet soda seem more refreshing than water, even before you factor in sweetness.
Caffeine: Diet soda’s little helper
Caffeine is next in line to explain diet soda’s popularity. Although it’s known as a productivity booster, it also adds a slight bitterness to cola.
People who make sodas have a tendency to say caffeine is there to affect the flavor,But there’s another camp that says the caffeine is at a level you can feel systemically, like a caffeine buzz that you would get from tea or coffee.
To be fair, diet soda’s dosing is relatively small compared to coffee. A 12-ounce can of Diet Coke contains 46 milligrams (mg) of caffeine, and Diet Pepsi has slightly less. That’s about half of what you’d find in an eight-ounce cup of joe,18 and less than 20 percent of a tall Starbuck’s Pike Place Roast..
Plus, the smaller caffeine dosage could lure people into thinking soda is okay to drink with dinner or before bedtime, which could interfere with sleep and even lead to weight gain.
Flavor enhancers: The X-factor
Why is Coke more popular than Pepsi?
Not because it’s sweeter or more carbonated or has more caffeine. It’s all the ingredients together, including the patented flavor enhancers that make Coke… taste like Coke.
“These ingredient combos stimulate the reward and hedonic centers of your brain,They also tap into the nature of human behavior.”
So, should you drink diet soda… or not?
There’s no clear-cut answer that applies to everyone.
As is often the case, the “right” choice isn’t dictated by the science alone. Instead, it’s dependent on what makes the most sense for you, the individual—with respect to both the evidence and your personal preferences, lifestyle, goals, and current intake.
Experts who recommend cutting out diet soda are essentially following the precautionary principle: Until something is proven without-a-doubt safe, it’s better to assume it isn’t. That might seem overly cautious to you, or it might make complete sense. Neither approach is wrong.
But that brings us to the diet soda drinker’s dilemma, and the real reason you’re still reading this article: What if you love diet soda, but you’re still concerned with how it might affect your health?
Step 1: Worry about what really matters first.
Based on the scientific evidence, there’s no compelling reason to stop drinking diet soda entirely.
“The risks of having excess body fat, on the other hand, are well-known and significant, If you’re replacing regular soda, or another highly caloric beverage, with diet soda, and it’s helping you lose weight or maintain a healthy weight, the benefits outweigh any potential downside.
Besides helping with weight control, there are other ways diet soda can support your health and fitness goals.
Maybe you’ve decided to drink less alcohol, and diet soda feels like a compromise you can live with in social situations. Or you want to have some caffeine in the morning or before your workouts, and you just don’t like unsweetened coffee or tea.
Think of the effort you spend on your health as a jar, If you have a choice between big rocks, pebbles, and sand, you’ll be able to fill up your jar fastest with big rocks. Afterward, you can fill in the cracks with smaller stuff, like pebbles and sand.
In the grand scheme of things, whether you choose to drink diet soda is a small rock. It might even be sand.
So, before you worry about changing your diet soda habits, focus on “big rocks” that make the most impact on your health, such as:
- eating mostly minimally-processed whole foods
- eating enough lean protein and vegetables
- eating slowly, until satisfied, and only when hungry
- getting adequate sleep
- managing stress
- moving regularly
- reducing excessive smoking/alcohol consumption
Unlike eliminating diet soda, there’s a wealth of evidence showing the above habits have a lasting effect on your overall health. Tackle the big stuff first.
Step 2: Lose the all-or-nothing mindset.
If you decide you want to drink less diet soda, you don’t have to go cold turkey.
In fact, there’s a wide range of choices available between drinking nothing but water and drinking a two-liter of Diet Pepsi a day.
- If you drink four diet sodas a day, could you substitute green tea for the morning one?
- If you normally have a diet soda every night with dinner, could you do that just three times a week instead?
- If you constantly crave the bubbly mouthfeel of diet soda, could you swap one or two a day for carbonated water (such as seltzer or sparkling)?
At first, these tweaks might not seem like much. But small, consistent changes made over time add up to lasting change.
Step 3: Remember: There’s no “best” way to eat… or drink.
As much as a universal, one-size-fits-all, “best diet ever” might make our lives simpler… it doesn’t exist.
Instead, it’s about finding a way of eating (and drinking) that works best for you as an individual.
Good nutrition is the goal, and it’s possible to accomplish that in a way you actually like. Even if it includes drinking diet soda daily.