Last Updated on November 9, 2023 by Fasting Planet
Can you fast on diet soda or pop? The fizzy pop of soda is one you know quite well, but not because you drink the full-calorie stuff. Instead, you prefer your soda to be diet instead. You know you’re supposed to watch your calories during a fast, which has you wondering, are diet drinks permissible? Can you fast and drink diet sodas?
Diet beverages may not have calories, but many contain artificial sweeteners that could break a fast. That said, as an occasional beverage you enjoy while fasting (or during a non-fasting period), diet soda may not be the worst choice. Unlike regular soda, which promotes weight gain, the diet stuff may be able to help you lose weight.
In this article, we’ll answer all your most pertinent questions about diet soda, including whether it’s truly zero-calorie or not, which varieties are healthiest, what your weight loss potential is, and whether this is the beverage you want to reach for on a fast. You’re not going to want to miss it!
Is Diet Soda Really Zero Calorie?
At first glance, diet soda almost seems too good to be true. It’s supposed to cut the calories and other ingredients that make its full-sugar counterpart such a bad beverage choice for your short-term and certainly your long-term health.
Just take a look at the nutritional information for a can of non-caffeinated cola courtesy of the USDA. Each time you drink the sweet stuff, you’re ingesting 150 calories, 39 grams of sugar, 39 grams of carbohydrates (13 percent of your recommended daily allotment), 11 milligrams of potassium, and 15 milligrams of sodium.
Considering you’re supposed to consume no more than 25 to 36 grams of sugar daily, a single can of soda already surpasses that. No wonder then that diet soda has become so appealing. Is this sugary drink really zero calories though?
To answer that, let’s yet again consult some nutritional information.
Diet Coke is a favorite for millions of people across the country. According to Coke’s website, 310 milliliters of the beverage contains 0 calories, 0.1 grams of protein, and 25 milligrams of sodium.
Sprite Zero Sugar, which is also owned by Coke, has zero calories per can and 35 milligrams of sodium per serving, which is only 2 percent of your daily recommended allowance.
So yes, the next time you get a craving for a diet drink, you can safely consume Sprite Zero Sugar or other Coke diet beverages in the same vein without worrying about adding calories to your day.
Does Drinking Diet Soda Make It Hard to Lose Weight?
Anytime you choose a low-calorie or no-calorie version of a food or beverage compared to its full-calorie counterpart, you’re making a better decision for your health, at least for the most part. We’ll discuss it more a little later in this article, but there are more nutritional elements to food and drinks that matter besides their calorie, such as sugar. Keep reading for more on that.
If you’re trying to lose weight, one of the first areas of your diet you may have looked at is the beverages you consume. Most people don’t think about it much, however when you drink anything but water or low-calorie beverages with your meal, you’re tacking on 100 to 200, sometimes even close to 300 calories to whatever you’re eating. Cutting out these drinks alone may help some pounds naturally drop off without you having to diet.
As for whether diet drinks make it difficult to lose weight, the studies done on the subject are conflicting. A 2012 report in The American Journal of Clinical Nutrition found that when you swap out caloric beverages for those with few or even no calorie, you may be able to induce weight loss at a rate of 2 to 2.5 percent.
A study done in the prior decade, also from The American Journal of Clinical Nutrition (different link) examined the connection between low-calorie beverages and weight loss. Their study involved the participants first receiving soda that was extra-sweet thanks to additional high-fructose corn syrup or aspartame. The quantity of sugary beverages the participants received was 1,150 grams a day, so quite a lot!
Next, the participants were weened off the sweet stuff. The researchers found that when the beverage had high-fructose corn syrup as an additional sweetener that the participants ate more calories over a three-week span. Yet using aspartame as a sweetener caused the participants to seek fewer calorie in that same timeframe. Further, the male participants lost some body weight, although the females did not.
Okay, so those are the studies that are for lower-calorie sweet drinks as a means of weight loss. What about the studies that are against that?
Well, in a 2014 report published in the journal Appetite, the researchers concluded that since the beverages the participants consumed weren’t sweet, the participants thus reached for other sources of dietary sugar. This could lead to more calorie ingested.
Physiology & Behavior, in a 2012 publication, noted that your appetite can increase if you consume sugar-free soda-like beverages. The reason for this is due to the low number of calories you ingest. As you crave more, your hunger hormones and sweet taste receptors both activate, creating changes in the brain and ultimately providing a dopamine release when you reward yourself with what you want.
Which Diet Soda Is the Healthiest?
If you’re going to choose diet soda, then you at least want to stick to the healthier varieties. Which ones are those? Here are four safe diet drinks to reach for when that soda craving strikes.
Bai5 Bubbles
One of the most renowned diet drinks for better health is Bai5 Bubbles. Per 11.5 fluid ounces of the Bolivia Black Cherry variety, you’re consuming 5 calories, 10 grams of erythritol (a type of sugar alcohol), 1 gram of sugar, and 11 grams of carbs. The ingredients in this beverage include sodium citrate, ascorbic acid, white tea extract, coffeefruit extract (no, not black coffee…), vegetable and fruit juices, citric acid, malic acid, cherry juice concentrate, and natural juice flavors.
Zevia Ginger Root Beer
If you love root beer but you’re trying to give up your soda habit, then try Zevia Ginger Root Beer. This diet drink contains 0 calorie and 0 grams of sugar. The ingredients list isn’t long either, only including citric acid, natural flavors, Stevia leaf extract, and carbonated water.
Sprite Zero
We talked about Sprite Zero a little earlier in this guide. Besides its low calorie and carb content, its lean ingredients list is also preferable. Sprite Zero is made with acesulfame potassium, aspartame, potassium benzoate, natural flavors, potassium citrate, citric acid, and carbonated water.
Diet 7Up
Skip the full-sugar 7Up and try Diet 7Up instead. A 12-fluid-ounce serving contains 0 calorie, 0 sugar, and 0 grams of carbs. You’ll also pass on the artificial coloring with this diet drink. The ingredients are calcium disodium EDTA, acesulfame potassium, aspartame, natural flavors, potassium benzoate, potassium citrate, citric acid, and filtered carbonated water.
Can I Drink Diet Soda While Fasting?
That brings us to the main question on your mind. During a fast, is it okay if you drink diet soda? How many of these beverages are recommended when fasting, one a day or as many as you want? Also, most importantly, can diet soda break your fast?
Before we answer these burning questions, let’s quickly talk about what it means to break a fast. When you’re fasting, you’re trying to limit the calories you ingest as well as the carbs and sugar. The reason you’re doing this is that food sources with carbs and sugar especially are known to add a lot of glucose to your body.
Glucose is a type of sugar that acts as your body’s energy source, giving you the fuel you need to get through your days. Each time you eat, you supply your body with a fresh source of glucose, which is then converted to glycogen. If your body has extra glucose that it doesn’t quite need, then the liver stores the glycogen for later.
When intermittent fasting, you significantly reduce the calorie you consume. Sometimes when you’re on a fast, you don’t eat any calorie at all. What this does is force your body to burn through the supply of glycogen during fasting, as well as the leftovers your liver has been holding onto.
Since your body can’t shut down entirely, as you continue fasting, your system eventually switches its energy source. Now, it uses fat for energy, burning this so you lose weight and look trimmer during and after fasting. Longer bouts of fasting may also lead to the burning of muscle proteins as well as fat, but this generally isn’t something you have to worry about with most types of intermittent fasting.
If you break a fast, you’re reintroducing calorie or sugar back to your body. The glucose that enters your system becomes the new energy source instead of fat, which stalls the progress you’re enjoying while intermittent fasting.
Now, some intermittent fasting experts believe that ingesting any calories will break your fast. Others say that you only break a fast if you ingest a lot of calorie. After all, some types of intermittent fasting allow you to eat a single meal a day.
So now that you know all that, let’s get back to discussing diet soda and whether it will break your fast. Since it has no calorie and some varieties even contain zero sugars and zero carbs, it might seem on the surface that a diet drink cannot break your fast.
Yet that’s not always true.
Whether a diet drink can interrupt your intermittent fasting progress has to do with artificial sweeteners or the lack thereof.
Sweeteners can be nutritive or non-nutritive. When a sweetener is nutritive, it means it boosts your energy if you eat it, often through the included calories. A non-nutritive sweetener cuts down on the calories but tends to contain a lot of sugary flavor. Like, a lot, between 100 times and 20,000 times more than nutritive sweeteners.
Several sugars in diet drinks are considered non-nutritive, such as Stevia, acesulfame potassium, and aspartame. Since diet soda is supposed to contain few if any calories, it makes sense that drink manufacturers would choose non-nutritive sweeteners since these control calorie well.
Still, even if a sweetener has no calories, it can still break a fast. How?
Sugar is glucose, and too much of it can influence your blood sugar or insulin levels. Thus, if you’ve gone long enough without sugar, such as when intermittent fasting, and you suddenly get a burst of sugar through a diet drink, you can bet that’s going to interrupt your fast.
What happens is your body triggers an insulin response, which causes the body to send glucagon and insulin back into the blood. By the way, glucagon is a hormone that’s supposed to prevent your blood sugar from dropping precipitously, which is known as hypoglycemia.
Insulin will tell your body to begin using the sugar you just ingested as an energy source, which does indeed put a stop to all that progress you’ve made on your fast. This can contribute to the misconception that intermittent fasting doesn’t work because you didn’t lose a lot of weight or body fat even though you stuck to consuming very few calories. In reality though, the beverage choices you made were to blame, not fasting.
Can I Drink Zero-Calorie Drinks While Fasting?
Okay, so we’ve established that the sweeteners used in your diet soda could cause an insulin response that adds sugar back to your body and thus prevents you from burning fat as your main energy source when fasting. That has you thinking a lot more carefully about the beverages you consume when intermittent fasting.
For example, are no-calorie drinks ever okay? To that, we say absolutely! In fact, there’s one beverage without any calorie that you should always strive to drink when on a fast, and that’s water.
Regular water has no sugar to trigger an insulin response, no carbs, and no calorie. It’s also your lifeblood, providing the hydration you need when intermittent fasting. Considering that you can lose as much as 20 percent of your daily hydration when you cut out food, it’s especially important to get into the habit of consuming water when on a fast.
You’ll also get an added benefit, which is providing a temporary feeling of fullness in your belly. When you can’t eat for a while because you’re intermittent fasting, this sense of satiety is definitely better than nothing.
As we talked about in a recent blog post, sparkling water and mineral water are generally safe to consume when intermittent fasting. These two carbonated beverages often have no calories, but do check that your sparkling drink uses natural flavoring instead of artificial flavoring.
Is It Okay to Drink Diet Soda Once in a While?
Imagine this: it’s day two of your intermittent fasting schedule and you’re really craving a diet soda. If you have just one, do you really have to worry about causing an insulin response that could disrupt your fast?
More than likely, yes. One exception would be if the main ingredient (or the only ingredient) in your diet drink is erythritol. For each gram of diet beverage you consume, you’re only ingesting 0.24 calorie from erythritol, which is not bad. It’s also been proven, such as in this study from the European Journal of Clinical Nutrition, that erythritol does not increase your insulin if you weigh about 150 pounds and ingest roughly 0.3 grams per kilogram of the stuff.
So some diet drinks may not necessarily disrupt your intermittent fasting progress, but that certainly won’t be the case with all. We’d recommend it’s best to wait until you’re done fasting before you begin drinking soda–diet or otherwise.
You can always try a product like Hint’s Kick beverages in the meantime. These caffeinated waters have no calorie, sugar, or carbs. Hint Kick tastes like diet soda but without the ingredients that could cause an insulin response when intermittent fasting. In the Black Raspberry Kick variety, you’ll find ingredients like natural caffeine, natural flavoring, black raspberry, and purified water. You might not even want to go back to diet soda (whether intermittent fasting or not) once you get hooked on a beverage like Hint Kick!
Conclusion
When intermittent fasting, you want to burn fat instead of glucose or sugar. The paltry few calories in diet soda might make it seem like a great beverage choice to sip on when fasting, but that’s not necessarily the case. The sweeteners in diet drinks tend to contain boatloads of sugar. This can cause an insulin response that breaks your fasting progress and may even inhibit weight loss.
Now that you know more about which drinks are and aren’t recommended when intermittent fasting, you can make smarter eating and drinking decisions. Best of luck!