Chicken bone broth (CBB) is a popular beverage for fasters, often consumed to manage hunger and maintain electrolyte balance during calorie restriction. Whether this savory liquid truly keeps the body in a fasted state depends entirely on a person’s specific fasting goals. Understanding the nutritional content of CBB and its metabolic effects provides the clear information needed to make an informed decision. The verdict is nuanced and based on the type of fast being performed.
What Defines “Breaking a Fast”?
What “breaks a fast” is not universal and relies on the specific metabolic goals a person is trying to achieve.
The simplest definition is the Caloric Threshold, which suggests that consuming more than a minimal number of calories interrupts the fasting state. Many practitioners use a limit of 50 calories to distinguish between a “dirty fast” and a water-only fast.
Another key consideration is the Insulin Response. This is the body’s reaction to macronutrients that cause blood sugar to rise and trigger the release of insulin. Since the primary goal of many fasts is to keep insulin levels low, consuming carbohydrates or high amounts of protein disrupts this state, signaling the body to switch from fat-burning back to sugar-burning.
The third and most sensitive definition relates to the Autophagy Threshold, the cellular cleanup process enhanced during prolonged fasting. Autophagy is highly sensitive to nutrient availability, especially protein or amino acids, which signal the presence of new building blocks. This signaling can downregulate the cleanup process, meaning the threshold for breaking the fast is essentially zero calories for maximum cellular renewal.
The Nutritional Profile of Chicken Bone Broth
A standard one-cup (240 mL) serving of chicken bone broth typically contains a very low amount of calories, ranging between 10 and 40. This minimal caloric content comes almost entirely from protein, with negligible carbohydrates and fat. The total carbohydrate content is often reported as zero or less than one gram, which is too low to cause a significant blood sugar spike.
The protein content is the most relevant factor, usually providing 3 to 9 grams per cup, primarily as gelatin and amino acids. These amino acids, including glycine, proline, and glutamine, are extracted from the collagen and connective tissues during simmering. CBB is also a source of important micronutrients, such as calcium, phosphorus, potassium, and sodium, which help maintain electrolyte balance during extended fasts.
Bone Broth’s Impact on Key Metabolic States
When analyzing chicken bone broth against the Caloric Threshold, it is generally acceptable for most intermittent fasts. Its 10 to 40 calorie count is well below the commonly accepted 50-calorie limit. This minimal intake is tolerated for weight loss or metabolic health goals, which prioritize the overall duration of the fast and the reduction of total caloric intake.
Regarding the Insulin Response, bone broth has a minimal impact because it contains almost no carbohydrates and very little fat. While the protein content can technically trigger a small insulin release, the amount is usually too small to pull the body completely out of a fat-burning state for most people. The body typically continues to produce ketones, meaning a fast focused on ketosis for fat utilization is generally not broken by a small serving of bone broth.
The verdict is less favorable for the Autophagy Threshold. The protein and amino acids in bone broth are seen as anti-autophagic signaling agents. Any consumption of protein signals the body that nutrients are available, potentially downregulating the cellular cleanup process. Therefore, if the primary goal is to maximize autophagy, consuming chicken bone broth is considered a break from the strictest definition of the fast.
Guidelines for Incorporating Bone Broth Into Your Fast
For those engaging in longer fasts (over 24 hours), consuming one to two cups of plain chicken bone broth per day can mitigate discomfort. The broth’s sodium and potassium content helps replenish electrolytes often depleted during extended fasting, preventing symptoms like headaches and fatigue. This practice makes longer fasts more sustainable without severely compromising the fat-burning state.
It is important to be selective with the type of bone broth used to avoid inadvertently consuming ingredients that will break the fast. The broth should be plain, free of added vegetables, spices, or fats that increase the calorie or carbohydrate count. People seeking maximum autophagy should avoid bone broth entirely and stick to water, black coffee, or plain tea to ensure no nutrient signaling occurs.
Bone broth is also useful as a bridge during the refeeding stage, offering a gentle transition back to solid food. Its gelatin content is soothing to the gut lining, making it an ideal first meal after a prolonged fast. Using bone broth in this manner supports digestive health.