Diet Soda and Ketosis

Sick of drinking water on the keto diet? Diet soda seems like the perfect solution. It’s sweet, it doesn’t have any added sugar, and the carb count is zero. But unfortunately, it’s not that simple.

The artificial sweeteners used in place of sugar disrupt your metabolism and prompt sugar cravings, which can interfere with your progress if you drink diet soda on keto.

Plus, although the jury is still out, artificial sweeteners have been linked to other health problems, like an increased risk of glucose intolerance, diabetes, metabolic syndrome, and obesity, according to a review published in the Indian Journal of Pharmacology.

What Are Artificial Sweeteners?

Artificial sweeteners are chemical replacements for sugar that offer the same sweet taste but without any of the calories or carbohydrates. They’re a lot sweeter than sugar, though. In fact, some of the most commonly used artificial sweeteners are 200 to up to 20,000 times sweeter, according to The Nutrition Source.

There are six artificial sweeteners and three natural, no-calorie sweetener approved by the U.S. Food and Drug Administration as generally recognized as safe:

• Aspartame
• Sucralose
• Neotame
• Saccharin
• Acesulfame-K
• Advantame
• Stevia
• Monk fruit extract
• Thaumatin

Food manufacturers developed artificial sweeteners so that people could still enjoy some of their favorite beverages, like diet soda, without any of sugar’s ill effects, like weight gain and metabolic disturbances.

But as consumption of artificial sweeteners increased, researchers started to discover that artificial sweeteners missed the mark. In fact, they come with some similar health problems and may even promote weight gain instead of weight loss.

Artificial Sweeteners and Sugar Cravings

When it comes to sugar cravings, artificial sweeteners seem like the best of both worlds. You get that sweet taste without any of the carbs or calories. But you know what they say: If something seems too good to be true, it probably is, and that’s the case here.

When you eat something sweet, it lights up several reward pathways in your brain that make you feel good in the moment. However, when the sweet flavor comes without calories, as is the case with artificial sweeteners, the pathways are only partially activated, according to a mini-review published in the Yale Journal of Biology and Medicine, which leaves your brain feeling like it’s missing out on something physiologically. And when your brain isn’t fully satisfied, it continually seeks more of what it wants. In this case: that sweet flavor.

If you regularly give in to sugar cravings, you develop both a tolerance and a preference for sweet flavor, even if you’re drinking artificial sweeteners instead of actual sugar. The more sweetness you have, the more you want and, ultimately, the more it takes to satisfy that craving.

On the other hand, if you cut out that sweet taste completely, your dependence and tolerance change, according to the same review in the Yale Journal of Biology and Medicine, and you don’t crave or feel satisfied by it as much when you do have it.

Artificial Sweeteners and Weight Gain

You might think that there’s no way you could gain weight from diet soda, since it doesn’t have any carbs or calories, but even though that’s true, it prompts weight gain in other ways.

According to a paper published in Current Gastroenterology Reports in 2017, artificial sweeteners can disrupt the bacteria in your gut, reduce your ability to feel full, and prompt you to eat more calories, three factors that can contribute to weight gain and obesity.

A study published in 2019 in Pediatric Obesity found that people who drink artificially sweetened beverages consumed up to 450 more calories per day than those who drink water instead. That’s because the sweet taste made them feel hungrier than they would have without it.

Artificial Sweeteners and Metabolic Dysregulation

The keto diet significantly reduces carb consumption and increases your intake of protein and fat. This causes what’s known as ketosis, a metabolic state where the body fuels itself with fat instead of carbs, according to StatPearls.

One of the main goals of ketosis is to regulate your levels of glucose and insulin, two of the major hormones that help you control your weight.

Diabetes Care reports that drinking diet soda works directly against the mechanisms of ketosis by disrupting both glucose and insulin. This, in turn, increases your risk of obesity, type 2 diabetes, and heart disease, according to Reviews in Endocrine and Metabolic Disorders.

Diet Soda and Ketosis

Because diet soda doesn’t contain any carbs or sugar, it won’t directly kick your body out of ketosis, but that doesn’t mean there’s no harm in drinking diet soda when you’re on a keto diet. If you’re trying to lose weight and balance your hormones, diet soda works directly against your goals, making it a counterproductive choice.

Plus, drinking diet soda will always keep your sugar cravings going strong, which can make it harder for you to stick to your low-carbohydrate plan and stay in ketosis for the long-term. On the other hand, completely cutting out sweet drinks and sweet foods on keto can help reduce, or even eliminate, those cravings.