Nutrition facts are believed to be reliable. After all, they are regulated by the government and are the most convenient way to be informed about what you are putting into your body. If you want to monitor your calorie, carbohydrate, sugar, or fat intake, you probably check the nutrition facts of everything you eat.
But labels don't always tell the whole story. Perhaps nothing illustrates that fact better than one of the most popular drinks in America: diet soda. The nutrition facts of many diet sodas seem surprisingly innocuous for such a tasty drink. For example, Diet Coca-Cola contains zero calories, zero grams of fat, zero grams of sugar and zero carbohydrates. Today, almost all diet soft drinks on the market contain no calories, sugar, fat or carbohydrates. Compared to regular soda, which is packed with calories, carbs and sugar, diet soda acts like a nutritional angel. Heck, it even has the wordcostsright in the name.
However, ask almost any nutritionist for their opinion on diet sodas, and they'll tell you that the zeros on the label don't necessarily mean they're harmless. For example,a recent study linked soda to obesity. How can a drink that contains almost no nutrients, both good and bad, have such an effect on our bodies? STACK spoke with Ryan Andrews, nutrition coach at Precision Nutrition, and Leslie Bonci, director of sports nutrition at the University of Pittsburgh Medical Center, to find out how diet soda can wreak havoc on your health.
Zero calories, full of flavor
How can diet soda taste so good despite containing no calories, sugar or carbohydrates? It's not magic, it's an artificial sweetener. Artificial sweeteners go by many names and give diet soda the taste you love.
“Most diet sodas are sweetened with aspartame,” says Andrews. “Others include stevia, sucralose, erythritol and acesulfame potassium. Some soft drinks contain a mixture of sweeteners.”
These artificial sweeteners are the key to diet soda's squeaky clean nutrition facts. Regular soda contains real sugar, and with real sugar comes calories and carbohydrates. One gram of sugar contains approximately one gram of carbohydrates and four calories. By avoiding sugar, diet soda avoids all the calories and carbohydrates that come with it.
For example, a can of regular Coca-Cola contains 140 calories and 39 grams of carbohydrates – almost all of which are a byproduct of the 39 grams of sugar. “Diet soda cannot contain calories, carbohydrates or sugar because it replaces sugar with artificial sweeteners. Artificial sweeteners are much sweeter than sugar. So it is possible to use a very small amount for the sweet taste and still have a very low calorie content," says Andrews. Some sweeteners are even 600 times sweeter than sugar.
'No calories' doesn't mean you don't have to worry
But what makes artificial sweeteners bad for you? If they don't add many calories, carbs, sugar, or fat to your drink, how can they negatively impact your body?
“There are a lot of theories about this,” says Andrews. “First, artificial sweeteners can change our ability to actually process sugar in the body.” With their sweet taste, artificial sweeteners can trick our brains into thinking we are consuming real sugar when we consume them.
When your body thinks it is ingesting sugar, it expects to ingest calories.
“The sweet taste of soda can be a stimulus for the brain to say, 'calories incoming, let's eat,'” says Bonci.
If it doesn't actually get those calories, your body will go into disarray. Over time, this behavior can wreak havoc on the way your body releases insulin, the hormone that helps convert sugar into energy. If your body has adapted to consuming artificial sweeteners, it may not release the right amount of insulin when you consume actual sugar. This can cause sugar to return to the bloodstream, which can cause things like diabetes and hyperglycemia.
Additionally, artificial sweeteners make you more prone to overeating by tricking your body into thinking it is consuming calories. “Since the body and brain are not actually consuming calories or carbohydrates, we may get signals for strong rebound hunger after consuming artificial sweeteners,” says Andrews.
A recent studyfound diet soda drinkers consume a similar amount of total calories per day as regular soda drinkers. This means they eat more calories from solid food than regular soda drinkers, offsetting any calorie deficit they may create from their low-calorie soda consumption. “Fewer calories in your glass can lead to more calories on your plate,” says Bonci.
Artificial sweeteners can also change the taste of food. “Our taste buds are consistent with what we're used to,” says Andrews. "If someone drinks highly sweetened soda every day, other naturally sweet foods, such as fruit, are unlikely to taste as sweet or be appealing. Then they will be drawn to even more processed and sugary foods in their diet."
Research has shown that the brains of soda drinkers actually look different than those of non-diet soda drinkers.A studyfound that as a participant's dietary soda consumption increased, a part of their brain known as the "caudate head" decreased in activity. The tail head plays a role in food motivation and satiety and helps send the signal that the sweet taste of sugar equals calories. If this part of the brain isn't active, your body won't help you naturally regulate your consumption of sugary snacks. Decreased activity in this area has been linked to an increased risk of obesity.
Sparkling addiction
Many experts agree that drinking a soda every now and then won't do you much harm. “If you're an otherwise healthy person and your biggest vice is soda a few times a week, you probably don't have much to worry about,” says Andrews.
However, many diet soda drinkers do not follow this consumption pattern. Many people drink diet soda at all hours of the day, almost as if it is an addiction. The most obvious answer to this behavior is the caffeine content of soda.Regular consumption of caffeinecan lead to an addiction, just like drugs such as alcohol or cigarettes. But caffeine may not play the only role.
The sweet taste of the sweeteners in the item has also been shown to be addictive. INone animal studyRats became addicted more easily to saccharin, a calorie-free artificial sweetener used in soft drinks, than to cocaine. Diet soda makes it exceptionally easy to become addicted to the sweet taste because it achieves this without the easily noticeable negative side effects of sugar consumption (such as crashes).
Ultimately, a diet soda every now and then won't hurt. But if you cut back on several a day and think it won't negatively impact your health, you're wrong. If you like the vibrant taste, opt for a smarter alternative. “Choose seltzers or sodas that have a punch of flavor and don't contain artificial sweeteners,” says Bonci.
RELATED:5 Drinks You Had No Idea Were Just as Bad as (or Worse Than) Soda
