• Autumn Bates, CCN, MS

Does Diet Soda Break a Fast? [Intermittent Fasting Tips]

Updated: May 27

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Diet soda typically contains zero calories... so does that mean you can have it during your fast and still achieve your weight loss and wellness goals? Not necessarily. Today I'm breaking down the deets of diet soda and Intermittent Fasting.

pssst... it's not too late to join the New Year Intermittent Fasting Challenge! Head over HERE for the details on how you can get started!

But First... What IS Diet Soda?

Diet soda is the soda industry's answer to sugar. Instead of using the typical sweeteners such as sucrose (table sugar) or high fructose corn syrup - both of which contain calories - they opt for the no-calorie options. These sweeteners include acesulfame potassium and aspartame. You may even see more natural ingredients to this zero calorie approach with options like stevia and monk fruit.

But how can these diet or zero calorie soda's TASTE sweet if it doesn't contain sugar? It all comes down to the difference between taste and energy. Calorie is just a measurement of energy (more specifically kcal). Your body can derive energy from protein, carbohydrates or fat. These sweetener alternatives are not broken down in a similar fashion as the macronutrients protein, carbs and fat. Because of this, our body can not derive energy from it. But what these sweeteners CAN do is provide a stimulus on your tongue that initiates the taste of sweetness. It's this bait-and-switch-on-your-body concept that diet or zero calorie sodas are capitalizing on. Sweetness without the energy.

Can You Have It During Your Fast?

Technically speaking... because most diet/zero calorie sodas do not contain protein, carbs or fat that can cause an insulin response, it won't break your fast. BUT if you're on your wellness journey, you're likely not looking to hack the system for short term results. You're looking for what will ACTUALLY help you feel good and achieve your wellness goals long term.

My main concern with diet soda is theoretical - yet something I have seen time and time again with my clients. Here's my hypothesis: because diet soda stimulates the sweetness taste factor but doesn't provide the energy that your body would typically expect to follow this stimulus - it confuses your brain and metabolism. Your body could start to increase insulin production because it thinks sugar is about to flood the system. When an additional source of sugar isn't in the blood supply, the secreted insulin will start to store your current blood glucose instead. This can lead to a drop in your blood glucose levels which will spur even MORE cravings.

And although this is a hypothesis, like I mentioned, I have seen it in action with my clients and AENpeeps. And the best way to tell what's going on is to see what happens when you stop.

Although diet soda technically does not break a fast, it isn't helping you achieve the goals you set out with Intermittent Fasting in the first place. And isn't that the point? Not to hack the system but to achieve REAL results?

New to Intermittent Fasting? Cut out the confusion and get step-by-step details and meal planning with the Complete Intermittent Fasting Bundle!

Tap into fat burning mechanisms, increase energy levels and start feeling GOOD again! Get started HERE!

Your Nutritionist,


Autumn Elle Nutrition


Manhattan Beach, CA



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Medical Disclaimer

This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors, nutritionists and/or qualified health professionals regarding specific health questions. Neither Autumn Elle Nutrition nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement or lifestyle program.

© 2020 by Autumn Bates, CCN

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