Why Intermittent Fasting Works And Why Zero Calorie Drinks Are So Important

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Many people are nowadays trying to lose weight by doing intermittent fasting, and they are right. But it’s not only about losing weight. There are also many other benefits like better cognitive function, improved metabolic flexibility, better digestion, more balanced energy levels, help with type 2 diabetes, fatty liver, higher stamina, and overall helping the body to regulate itself. It’s really a powerful method, but like everything related to health, we need to understand a few key things to do it properly and get the most out of it.

One of those important things, which is often overlooked, is what you drink during the fasting period. And that’s where zero calorie drinks come in. Not all drinks labeled “zero calorie” are suitable for fasting, and in this post, we’re going to break it all down. But first, let’s start from the beginning.

1. What Is Intermittent Fasting, Really?

Let’s get something clear: intermittent fasting is not about eating less. It’s about eating what you need—but in a shorter window of time. For example, a popular fasting schedule is 16:8, where you fast for 16 hours and eat during an 8-hour window. Others might do 18:6 or even one meal a day (OMAD), depending on their goals.

During the fasting hours, your body switches from using glucose (sugar) for energy to using stored fat. This switch helps regulate blood sugar, improve insulin sensitivity, and burn fat more efficiently. It also gives your digestive system a break and supports things like autophagy, which is the body’s natural process of cleaning out damaged cells.

2. Talk to Your Doctor First

Before starting intermittent fasting, especially if you have any health conditions, it’s very important to talk to your doctor. Everyone is different, and some people may have specific contraindications—whether it’s diabetes medications, hormone imbalances, or other medical factors. Fasting is powerful, and with that power comes responsibility. Make sure it’s right for you.

06/06/2025 03:50 pm GMT

3. Intermittent Fasting Is About Timing—Not Starving

Here’s the thing: intermittent fasting doesn’t mean eating fewer nutrients. It means eating the right amount of nutrients, just in a specific time frame. That includes getting enough protein, healthy fats, quality carbs and micronutrients. If you’re training or active (which I recommend during fasting!), it’s even more important to hit your nutritional targets during your eating window.

As I explained in my blog post about supplements, daily protein intake is essential—especially if you’re doing strength training or trying to preserve or gain muscle while losing fat. Make sure you’re not under-eating just because you have less time to eat. Not eating your daily requirements it’s never going to take you to a successful place. It is much better to over eat than eating less 

4. The Truth About Zero Calorie Drinks During Fasting

Now let’s get into what might be the most underrated part of fasting: what you drink.

A lot of people assume that anything labeled “zero calorie” is fair game—but that’s not always true. Not all zero calorie drinks are fasting-safe, especially if your goal is to stay in a fasted state, keep insulin low, and let your body burn fat efficiently.

Approved Zero Calorie Drinks for Fasting:

  • Water – Still or sparkling, plain or with a splash of lemon or a tiny bit of apple cider vinegar. No sweeteners.

  • Black Coffee – No sugar, no cream, no milk, no flavored syrups. Coffee can actually support fat burning and suppress appetite.

  • Unsweetened Tea – Green tea, herbal teas, black tea—all are great choices, just make sure there are no added sweeteners or hidden ingredients.

  • Apple Cider Vinegar in Water – Just a teaspoon or so in a glass of water can support digestion and appetite control.

What to Avoid:

  • Coke Zero, Diet Coke, and Similar – Yes, they say zero calories, but the artificial sweeteners can still trigger an insulin response or cravings.

  • Flavored Waters with Sweeteners – Even if the label says zero calories, things like stevia, sucralose, and monk fruit can affect your metabolic state.

  • Protein Waters or Collagen Drinks – Even small amounts of protein or amino acids can break your fast.

The goal during the fasting window is to keep insulin low and avoid anything that could tell your body, “Hey, food is coming!” That’s why the right zero calorie drinks are essential. They keep you hydrated, support your fast, and don’t interfere with the benefits.

06/06/2025 02:19 pm GMT

5. Exercising During Your Fast – A Big Win

Let’s talk about another big one: exercise during your fasting period. A lot of people think they need to eat before a workout or immediately after. But the truth is, your body is fully capable of training in a fasted state—as long as you’re fueling properly during your eating window.

Fasted exercise helps your body tap into fat stores for energy. It improves metabolic flexibility and boosts fat burning. You also get a natural increase in human growth hormone, which helps with muscle repair and recovery.

So don’t be afraid to hit the gym or go for a run while fasting. You might actually feel more clear-headed and focused. And don’t worry so much about “anabolic windows” or needing to slam a shake right after training. As long as you’re getting what you need each day, your body will handle it.

6. Final Tips to Maximize Your Fasting Results

If you’re just starting out with intermittent fasting, or if you’re already doing it and want to get more out of it, here are a few final tips:

  • Hydration is key. Drink water and fasting-approved zero calorie drinks throughout the day.

  • Start gradually. If 16:8 feels too hard, begin with 12:12 and work your way up. 12 hours is the minimum to start being considered Intermittent Fasting

  • Break your fast wisely. Start your eating window with protein and whole foods, not sugar or processed snacks.

  • Be consistent. Fasting is like a muscle—the more you train it, the easier it gets.

  • Don’t fear exercise. Train during your fasted window to maximize fat burning and build metabolic flexibility.

  • Never eat less. Remember that the main point here is to leave your insulin to rest so that your body becomes keto-adapted (your body has adapted to running on fats and ketones instead of glucose). With intermitent fasting your body will learn how to activate this process quicker and you will never feel lack of energy ever again. Eating less is only going to bring us a lot of problems and of course we are not going to reach any of our goals.

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