I’m always surprised when I speak to people who say they eat healthfully but drink diet soda. We’ve known for a long time that diet soda isn’t healthy for us, so it’s surprising that so many folks keeping drinking it. Here are some very good reasons not to.

According to “The skinny on diet soda” by Mandy Oaklander (Time Magazine, 3/30/15), what we like about drinking diet soda is the rush it gives us—without the calories. The truth is that while we’re believing that diet soda is helping us slim down, it’s actually fattening us up. When you intake genuine sugar, your brain registers satiation with it and gets “full” on sugar. Says, Dr. Helen Hazuda of the University of Texas Health Science Center, “Your body is used to knowing that a sweet taste means you’re ingesting energy”—that is, calories—“and that if you don’t burn them off, it’s going to convert them to fat.”

That’s how the body works, but it gets confused with artificial sweeteners which are often hundreds of times sweeter than sugar. Therefore, it doesn’t register them as energy and there’s no sense of satiation. Studies tell us that “no-calorie sweeteners interfere with a natural ability to regulate incoming calories” leading to “sugar cravings and weight gain.” Moreover, “Sometimes…we overestimate the calories we’re saving from drinking diet soda, so we splurge on fries or cookies, thinking it’s okay since we added a diet soda.” (AARP Bulletin, 12/15, “Ask our experts,” p. 38)

Recent research concluded that drinking even one can of diet soda a day can lead to a “34% higher risk of metabolic syndrome, a cluster of risk factors that can lead to heart disease and Type 2 diabetes.” A recent “study in Nature found that artificial sweeteners changed the colonies of gut bacteria in mice in ways that made the animals vulnerable to insulin resistance and glucose intolerance, which are metabolic disorders that can lead to weight gain and increase the risk of Type 2 diabetes.” Eat fewer foods with real sugar in them instead of ones with artificial sweeteners and you’ll stay healthier.

If you’re a diet soda drinker, now that you have this information, what will you do with it? Pretend you never read this blog or swap out diet soda for the real deal? Or decide that diet soda—and all soda—is unhealthy and that you can learn to enjoy drinking water. Making the switch is a major, positive change in your life. Many people have done it and are happier and healthier now. Start today and in a few weeks, you’ll crave diet soda less and be satisfied with just plain water.