Can I Drink Diet Coke On OMAD?

In this post I will explain everything you need to know about diet sodas with fasting, and if you can you drink diet coke on OMAD.

You can drink diet coke on OMAD because it doesn’t have any calories. Non-caloric artificial sweeteners that are found in diet soda are not associated with an increase in insulin and fasting glucose, therefore they don’t affect the lipolysis (fat burning) process.

There are some studies that show people who consume a high amount of diet sodas tend to have high blood sugar levels, however, it is not correlated to diet sodas (source).

diet coke on omad

Does Diet Soda Break Intermittent Fasting?

Diet soda doesn’t break the fast because it has zero-calories, therefore it doesn’t spike insulin levels. Breaking the fast means switching the body from the fasted state, where it uses mainly fatty acids as a source of energy, into glycogenesis (storing glucose in form of glycogen).

This means as the sugar enters the body, the pancreas releases insulin to transport glucose molecules and store them in the liver, muscles, and fat cells as an available energy source in form of glycogen.

Remember that insulin is released in proportion to the sugar in the blood, so even if you have one regular soda, or coffee with sugar, the proportion will be relatively small.

This means as soon as the glucose is absorbed in the form of glycogen, it will be immediately used as a primary source of energy.

This means in just a couple of hours after your beverage, even if it has some sugar, you will be back in the fasted state. This happens due to the metabolic flexibility of the body. During the times of energy intake (when we eat food), our body will extract nutrients from that food and use them for energy (source).

But in times of low or non-energy intake, our body uses internal sources of energy (stored body fat). In fact, there are over 14 ways of how our body will use energy, depending on the environment (food availability).

Carbohydrates metabolism

Carbohydrates Pathways
GlycogenesisFrom glucose to stored glycogen
GlycogenolysisFrom glycogen to glucose
GlycolysisFrom glucose to pyruvate
Krebs cycleAcetyl-CoA to ATP
GluconeogenesisNon-carbohydrates to glucose

Fat metabolism

Fat Pathways
Triglyceride and fatty acid mobilization
Ketone formation
Fatty acid synthesis
Triglyceride synthesis
Cholesterol synthesis and catabolism

Protein metabolism

Protein Pathways
Amino acid pool
Amino acid catabolism
Deamination and transamination

This is called metabolic flexibility.

So as you can see, being metabolically flexible means to adjust on the spot, depening on what source of energy is available.

Back into the soda example. Even if you have a small amount of sugar in your regular soda, it will break the fast, but only temporarily. Because as soon as it uses all the energy from sugar, it will switch back to using fat.

Can I Drink Diet Coke While Trying To Lose Weight?

You can drink diet coke while trying to lose weight because diet coke doesn’t increase blood glucose levels. Diet beverages with non-calorie sweeteners can be an effective tool for weight loss and maintenance, however, they must be consumed within the limits.

Here’s how it works.

When you drink regular calorie beverages, it activates the food reward pathways in the brain, specifically in the hypothalamus area. So after you have a caloric beverage, your brain gets post-ingestive satisfaction. It’s like a craving that has been satisfied. And with occurring satisfaction, the body doesn’t seek out more.

But when you consume beverages with artificial sweeteners, there is no activity in the food reward pathways. This means your brain doesn’t get post-ingestive satisfaction. So your appetite and cravings may continue, which can trigger unwanted food-seeking behavior (source).

picture of diet soda vs regular soda

So drinking a diet soda while trying to lose weight may not directly relate to weight gain, if you consume a lot of it it can trigger you to break the fast and wanting to eat. As with everything, moderation is the king.

Does Coke Zero Spike Insulin?

Coke Zero doesn’t spike insulin because it has zero calories. Insulin is released by the pancreas in response to elevated sugar levels in the blood and redistributes excess sugar throughout the body. Coke Zero doesn’t have any sugar, therefore it doesn’t trigger insulin to spike.

For people who need to control their sugar levels, drinking beverages that are sweetened with non-nutritive or artificial sweeteners is a great alternative, as a opposite to regular sodas.

Some studies suggest that zero-calories drinks are associated with a high risk of metabolic syndrome, but the problem with those studies is that they are all observational and experimental (source).

Observational studies mean that people get a questionnaire with a number of questions to be answered, and based on those findings they concluded that people with sugar problems also happen to consume zero-calories beverages.

But correlation doesn’t mean causation.

This is like saying that people living in Florida have the highest divorce rate and the highest margarine consumption. Therefore, high divorce rates are related to eating too much margarine. Which is complete rubbish because non of those two are somehow related.

Can I Drink Diet Soda On OMAD?

You can drink diet soda on OMAD because diet soda doesn’t affect ketosis. Intermittent fasting works around 8-12 hours after your last meal where you enter into the fasted state. The only way to get out of ketosis is by eating a meal or consuming regular sugary drinks.

This means you can easily have a couple of cans of diet soda while doing one meal a day. This will help you reduce some of the cravings for the sweetness that you may have on OMAD. But you have to be aware that the more you drink articifial sweeteners, it can actually increase those cravings even more.

This means if you consume diet sodas in large quantities, it can backfire and make you more hungry. Having just a couple of cans of diet soda per day won’t make big difference in the cravings, but can help you sustain yourself throughout the day.


Diet coke won’t make you gain weight because it has zero sugar therefore it doesn’t spike insulin levels. Insulin is an anabolic hormone that triggers fat storage after ingesting food or consuming drinks with calories. Therefore, having diet coke won’t make you gain weight.

Go Further with OMAD

This article is part of the What To Drink On OMAD.

In the following articles, I show you everything there is to know about drinks and how to stay hydrated with OMAD for the best results.

Learn more: Click here to read the article about can I drink coconut water on omad

Michal Sieroslawski

Michal is a personal trainer and writer at Millennial Hawk. He holds a MSc in Sports and Exercise Science from the University of Central Lancashire. He is an exercise physiologist who enjoys learning about the latest trends in exercise and sports nutrition. Besides his passion for health and fitness, he loves cycling, exploring new hiking trails, and coaching youth soccer teams on weekends.

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