Why Does Chicken Not Have Carbs? The Scientific Reason Explained

November 21, 2025 •

4 min read

According to the USDA, a standard serving of plain, boneless, skinless chicken breast contains zero grams of carbohydrates. But why does chicken not have carbs when it comes from an animal that consumes them? This is due to a natural biochemical process that occurs after the animal is slaughtered.

Quick Summary

This article explores the biological and chemical reasons behind the absence of carbohydrates in chicken. It explains how glycogen, the animal's energy store, is depleted during and after slaughter, resulting in meat with a negligible carb count. The summary also clarifies exceptions, such as organ meat, and discusses how added ingredients can alter the nutritional profile.

Key Points

Glycogen Depletion: A chicken's stored glycogen, its carbohydrate energy source, is depleted after slaughter through a process called glycolysis.
Postmortem Conversion: The breakdown of glycogen into lactic acid causes the muscle tissue to become meat, resulting in a negligible carb count.
Additives Add Carbs: The carbs in many chicken dishes come from external ingredients like breading, marinades, or sauces, not the chicken itself.
Organ Meats are an Exception: Unlike muscle meat, organ meat like liver can contain a small, measurable amount of residual carbohydrates.
Read Labels Carefully: Processed chicken products should be checked for added sugars, starches, or binders that introduce carbohydrates.
Natural Purity: Plain, unprocessed chicken is a high-protein, zero-carb food, ideal for low-carb and keto diets.

The Biological Explanation: Glycogen Depletion

At a fundamental level, the reason why chicken does not have carbs comes down to the way animals store and use energy. Unlike plants, which store energy as starches and sugars, animals store glucose in the form of a complex sugar known as glycogen. This glycogen is stored primarily in the liver and muscle tissue.

When a chicken is alive, its muscles are constantly using and replenishing glycogen for energy. However, once the animal is slaughtered, its biological processes begin to shut down. The muscle cells, deprived of a constant oxygen and nutrient supply, continue to function for a short period, using up the remaining glycogen stores. This process is known as glycolysis.

The Postmortem Conversion of Muscle to Meat

During this postmortem process, the stored glycogen is broken down into lactic acid. This chemical change causes the pH of the muscle tissue to drop, a critical step in the conversion of muscle to meat. By the time the chicken meat is processed and arrives at the grocery store, virtually all of the glycogen has been used up. The amount of residual glycogen is so small that it is considered nutritionally insignificant, hence the official 'zero carbs' label.

Potential Carb Content: Additives and Exceptions

While fresh, unprocessed chicken is carb-free, not all chicken dishes fit this description. The presence of carbohydrates in a chicken meal is almost always the result of added ingredients, not the meat itself. Consumers following low-carb diets must be mindful of how their chicken is prepared and what accompanies it.

Common Sources of Added Carbohydrates

Breading and coatings: Frying chicken in breadcrumbs, flour, or other coatings adds a significant amount of carbohydrates.
Sauces and marinades: Many popular sauces, such as barbecue, teriyaki, and sweet and sour, are high in sugar, a form of carbohydrate.
Fillers and binders: Processed chicken products, like nuggets or reformed patties, may contain fillers or binders that add carbs.

Notable Exceptions: Organ Meats

It is also important to recognize that not all parts of the animal are completely free of carbohydrates. The liver, for example, is an exception. It serves as a major glycogen storage organ in a living animal, and while most of this is depleted, some residual glycogen may remain. According to Britannica, liver can contain up to 8% carbohydrates, making it a rare instance of an animal product with a measurable carb content.

Comparison Table: Fresh vs. Processed Chicken


Feature	Fresh, Unprocessed Chicken	Processed or Prepared Chicken
Carbohydrate Content	Typically zero grams	Varies, often high due to additives
Example	Plain grilled chicken breast	Fried chicken nuggets
Nutritional Profile	Primarily protein and fat	Contains carbs, fats, and possibly sugars
Common Use	Keto, paleo, low-carb diets	Standard restaurant meals, convenience foods
Ingredient Purity	One ingredient (chicken)	Multiple ingredients, often with added sugars, flour
Postmortem Process	Glycogen depleted entirely	Glycogen depleted, but carbs added back

The Verdict on Low-Carb Diets

For those on low-carb or ketogenic diets, the lack of carbohydrates in fresh chicken makes it a dietary staple. Its high protein content is crucial for muscle repair and satiety, while the zero-carb profile helps maintain a state of ketosis. It's a versatile and effective food for managing weight and blood sugar levels, provided it is prepared without added sugars or starchy coatings.

Conclusion

The reason why chicken does not have carbs is a fascinating example of biology and food science. It is not because the animal never had carbohydrates, but because of the natural depletion of glycogen during the postmortem conversion of muscle to meat. This process leaves a final product that is rich in protein and fat but devoid of carbohydrates, solidifying its place as a go-to food for health-conscious consumers. By understanding this process, one can make more informed decisions about which chicken products to choose, ensuring their meals align with their nutritional goals.

The Glycogen Conversion Process: A Summary

Here is a simple breakdown of how a chicken goes from having carbohydrate stores to being a carb-free food:

Glucose Intake: An living chicken consumes carbohydrates, which are converted into glucose and stored in its muscles and liver as glycogen.
Slaughter: When the animal is slaughtered, the oxygen supply to its muscles is cut off.
Glycolysis: The muscle cells continue to use their stored glycogen for energy in a process called anaerobic glycolysis.
Lactic Acid Production: This process converts the glycogen into lactic acid.
Depletion: By the time the chicken is ready for consumption, the glycogen stores are fully depleted, leaving virtually no carbohydrates.

For a deeper dive into the science of meat processing, the Britannica article on the subject provides extensive information on postmortem muscle changes.

The Importance of Reading Labels

For anyone monitoring their carbohydrate intake, this knowledge is power. The zero-carb nature of fresh chicken is a major benefit, but the modern food industry means processed products can be misleading. Always check the nutritional information and ingredient list on any pre-packaged chicken item to avoid hidden sugars or starches that could undermine a low-carb diet.

Not All Meats Are Equal

While chicken and other muscle meats are carb-free, it is worth remembering that different animal products have different nutritional profiles. Organ meats, as mentioned, are an exception, but other products like milk and yogurt contain varying amounts of lactose, a type of carbohydrate. Knowing these differences helps build a comprehensive understanding of nutrition.

A Final Word on Natural Foods

Ultimately, fresh, unprocessed foods are the key to truly controlling your macronutrient intake. By choosing a plain chicken breast over processed nuggets or sauces, you are in complete control of what you consume. It is a straightforward principle that underpins many successful dietary approaches, from ketogenic to paleo.

Frequently Asked Questions

Glycogen is the form in which animals, including chickens, store glucose for energy. It is relevant because this glycogen is broken down and depleted during the postmortem conversion of muscle to meat, resulting in a product with virtually zero carbohydrates.

Most muscle meat from animals, including beef and pork, is naturally carb-free for the same reason as chicken: the depletion of glycogen stores after slaughter. However, exceptions exist, such as organ meat like liver, which can contain small amounts of residual carbohydrates.

A chicken dish will have carbs if it includes ingredients with carbohydrates, such as breading, flour, sugary sauces (like barbecue or teriyaki), or starchy fillers found in processed products like chicken nuggets.

Plants store energy in the form of starches and sugars, which are abundant and remain in the plant after harvest. Animals store energy as glycogen, which is used up during the postmortem process, leaving the final meat product with negligible carbohydrates.

Chicken liver is an exception to the zero-carb rule for chicken. It can contain a small percentage of carbohydrates due to its function as a major glycogen storage organ. While still relatively low-carb, it is not a zero-carb food like muscle meat.

Freezing plain chicken does not add carbohydrates. However, processed chicken products, like frozen breaded chicken strips, often contain additives such as breading and sugars to enhance flavor or texture, which do contain carbs.

Yes, through a process called gluconeogenesis, the body can convert excess protein into glucose. However, this is an endogenous process by the body and is not equivalent to consuming dietary carbs. For most people, it has a negligible effect on blood sugar levels compared to eating a carb-heavy meal.