Does collagen break a fast?

Does collagen break a fast?

Updated: Mar 26, 2024Veronika Larisova

Some health experts have hypothesised that collagen protein might not break a fast nor affect autophagy. The truth is that nobody knows for sure, as all scientific research on fasting and intermittent fasting used a complete abstinence from calories during the fasting period.

Collagen supplements are a form of protein, and like any protein, they can indeed break a fast.

When you consume protein, it causes a response in the body that leads to the secretion of insulin, which is the hormone responsible for signalling cells to take up glucose from the blood. This response is contrary to the fasting state, where insulin levels are typically low.

During a fast, your body switches from using glucose as its primary energy source to using fat, known as ketosis. Introducing proteins, like collagen, into the body can interrupt this process because amino acids in protein can be converted into glucose through gluconeogenesis.

Any increase in blood glucose will break the fast, which for some people can also happen after drinking just black coffee! You simply won’t know unless you wear a glucose monitor. The easiest way around it is to stay away from anything other than water while fasting, regardless of the length of the fast, including intermittent fasting.


Our tip for breaking a fast

Break the fast with black coffee + 1 scoop of Chief Collagen Protein, train, and then have a protein-containing meal.

This applies to intermittent fasting only. Don’t break a prolonged fast with a coffee. You need to follow a specific refeeding protocol if fasting for more than 3 days.


What’s your why?

It’s essential to ask yourself, WHY are you fasting? If you are after weight loss, you can get away with a collagen coffee, but if you are after other health benefits such as increasing longevity, slowing down aging, improving mitochondrial function, autophagy (the body's process of cleaning out damaged cells and regenerating new ones), reducing inflammation and preventing chronic disease, you might want to stick to water only.

Most of the processes related to anti-aging, such as autophagy, are upregulated in response to nutrient deprivation, and eating protein would signal to the body that nutrients are available again.


The protein dilemma

If you fast to slow down aging and upregulate autophagy, you should eat a diet low in protein. Scientific findings suggest that a diet low in protein can affect longevity positively by dialling down specific body processes that, when too active, may contribute to aging.

Think of your body like a machine: if it's always running at full capacity, parts wear out faster. A low-protein diet can be like turning down the dial, reducing the "speed" at which aging processes occur, thus potentially leading to a longer life.

But here's where it gets interesting: the body needs protein for many vital functions, like keeping muscles and bones strong, supporting the immune system, and healing wounds, to name a few. So, completely ditching protein isn't the answer because we'd risk losing lean muscle mass, becoming weak, getting sick more often, and taking longer to recover from injuries. 

The solution could be regular fasting or a fasting-mimicking diet, which are eating patterns that reduce protein intake for short periods. This approach can give the body a break from high-protein intake, allowing it to reap the longevity benefits, but then normal protein eating resumes to ensure muscles and immune function stay healthy.

It's like periodically giving your car a rest instead of running it non-stop, which can extend its lifespan without sacrificing the performance you need for daily tasks. This balance might help maintain the health benefits of protein while still tapping into the longevity perks of a lower-protein regime.

You can easily achieve this by regular fasting or intermittent fasting. And if neither is appealing to you, there’s another option: THE FASTING MIMICKING DIET. The good news is that you can have your collagen coffee and any Chief products as a part of this eating regime!


The Fasting-Mimicking Diet

A fasting-mimicking diet (FMD) is a specialised eating plan that aims to provide the benefits of fasting without the need to abstain from food completely. It typically involves a reduced calorie intake, low in proteins and sugars but high in unsaturated fats, for a set period.

These diets are designed to promote beneficial cellular and metabolic changes similar to those during water-only fasting, such as activation of pathways associated with longevity, reduced inflammation, and cellular clean-up processes.


Here are general guidelines for an FMD, based on scientific research, particularly the work of Dr. Valter Longo, a leading researcher in the field:

Duration: The FMD usually lasts about 5 days, repeated every 1 to 6 months, depending on individual health goals and under medical supervision.

Caloric Intake: Caloric intake is typically reduced to approximately 40-50% of an individual's typical daily calorie needs. On the first day, calories might be 1090 kcal (10% protein, 56% fat, 34% carbohydrate), followed by days 2-5 with around 725 kcal (9% protein, 44% fat, 47% carbohydrate). Our Chief Collagen bars are the perfect FMD dessert.

Macronutrient Composition: The diet is low in proteins and carbohydrates but rich in healthy fats. This composition is key to initiating the body’s fasting state.

Micronutrient-rich foods: The intake of vitamins and minerals is maintained to support overall health despite the reduction in calories. You can biohack this by taking our whole food supplements.

Hydration: Adequate hydration with water and non-caloric beverages is emphasised.

Supervision: It is crucial to undertake this diet under medical supervision, especially for individuals with pre-existing health conditions.

The ProLon Fasting Mimicking Diet, developed by Dr. Longo and his colleagues, is one of the commercial diets that encapsulate these principles.



If you are fasting for weight loss, having collagen in your coffee might be beneficial because it fills you up and curbs your appetite, thus resulting in consuming fewer calories across the day. A great tool for creating a calorie deficit (necessary for weight loss) without hunger pangs.

If fasting for health benefits and antiaging, stick to water only during the fast and use coffee+collagen to break the fast. Unless you are fasting longer than three days, in which case you must follow a specific refeeding protocol.



Veronika Larisova
Co-Founder, Registered Nutritionist, Exercise Physiologist
Book a free nutrition consultation 



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