Sick of water on keto? 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.
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 range from 200 to up to 13,000 times sweeter. There are six artificial sweeteners and one natural, no-calorie sweetener approved by the FDA as generally recognized as safe (or GRAS):
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 hand in hand with some of their own, 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 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, 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.
Another study published in 2019 in Pediatric Obesity reported 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
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 keto. 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.
Safe Low-Carb Soda
As more research comes out about artificial sweeteners and the potential health risks of diet soda, manufacturers are responding by offering diet soda made with stevia, a natural, no-calorie, no-carb sweetener. There isn't much research on whether or not this natural, no-carb sweetener has the same effects as artificial sweeteners.
However, one study published in the journal Appetite in 2010 reported that stevia may actually improve insulin sensitivity and have positive, beneficial effects on both glucose and insulin levels. Because there's limited research, it's difficult to make definitive statements about the effects of stevia, but it seems to be a better option for those considering drinking diet soda on keto.
Avoid Diet Soda on Keto
Although diet soda won't kick you out of ketosis, it disrupts your metabolism in other ways and makes it harder for you to lose weight. The artificial sweeteners in diet soda are also connected to other health issues, like:
- Multiple sclerosis
- Parkinson's disease
- Alzheimer's disease
If you're trying to improve your health and lose weight, it's best to stick with water as much as possible. If you're looking for other keto-friendly beverages, opt for herbal tea or flavored, sparkling water. You can also add some fresh mint or cucumber to your water and make an infusion.
- Harvard T.H. Chan School of Public Health: Low-Calorie Sweeteners
- Indian Journal of Pharmacology: Artificial Sweeteners as a Sugar Substitute: Are They Really Safe?
- Current Gastroenterology Reports: The Association Between Artificial Sweeteners and Obesity
- Pediatric Obesity: Consumption of Low‐Calorie Sweetened Beverages Is Associated With Higher Total Energy and Sugar Intake Among Children, NHANES 2011–2016
- Reviews in Endocrine and Metabolic Disorders: Artificial Sweeteners and Metabolic Dysregulation: Lessons Learned From Agriculture and the Laboratory
- Diabetes Care: Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load
- Yale Journal of Biology and Medicine: Gain Weight by “Going Diet?” Artificial Sweeteners and the Neurobiology of Sugar Cravings
- Appetite: Effects of Stevia, Aspartame, and Sucrose on Food Intake, Satiety, and Postprandial Glucose and Insulin Levels
- American Diabetes Association: Low-Calorie Sweeteners