Short answer: technically, yes. A cup of bone broth contains protein and a small amount of energy, so by the strictest definition it breaks a fast. Practically, it depends on why you are fasting. A cup of our chicken broth has 24 Calories and 4.3g of protein, which is very little compared with a meal, and some people use it to make a fasting window easier to stick to. Whether that trade-off is worth it is your call.
This article explains the distinction, why people reach for broth during intermittent fasting, and how to use it sensibly.
What counts as “breaking” a fast?
It depends on whose definition you use, and that is the source of much of the confusion online.
The strict definition. A fast means no energy intake at all. By this measure, anything with Calories or protein ends the fast, broth included.
The practical definition. Some people practising time-restricted eating, such as the 16:8 pattern, use a small intake as a compromise to make their routine easier. That still ends a strict fast, even if they continue to describe the period as their fasting window.
For medical tests, surgery or other procedures, follow your clinician’s fasting instructions rather than general food advice.
What is in a cup of bone broth?
One serve of Byron Bay Organic Chicken Bone Broth Powder, made with 200ml of hot water, contains 100kJ (24 Calories), 4.3g of protein, less than 0.1g of fat, 1.6g of carbohydrate and 245mg of sodium.
For comparison, a flat white made with full-cream milk is typically well over 100 Calories. Broth contains much less energy than a meal, but it is not energy-free.
Why do people drink bone broth while fasting?
People who use broth during intermittent fasting tend to give the same few reasons.
A warm, savoury drink. Some people find it makes the last hours of their planned window easier. That is a matter of experience rather than evidence that broth preserves a fast.
It is savoury, not sweet. Broth offers a different flavour from many comfort drinks. Some people find a savoury drink easier to fit into their routine than a sweet one.
Salt. A cup contains 245mg of sodium. Account for this alongside the rest of your food, especially if you have been advised to limit salt.
A light first food. Many people choose something warm and light before a full meal. Broth is a traditional choice for that.
What does the research say about fasting itself?
Intermittent fasting has been studied widely, and reviews in leading journals describe a range of potential metabolic effects of extended gaps between meals. The research is still developing, much of it was done in animals, and results in people vary.
What we do not have is good human research on what a small amount of broth does inside a fasting window. Claims online that broth “keeps you in ketosis” or “won’t affect autophagy” go beyond the evidence. Neither broth nor a particular fasting routine can guarantee those outcomes.
How to use bone broth around intermittent fasting
If you decide broth earns a place in your routine, a few habits keep it simple.
Keep it to one cup. Several cups across a morning add up, especially in sodium.
Consider it your first food. Having broth when your planned fasting window closes avoids confusion about whether you have ended a strict fast.
Keep it plain. Adding butter, oil or cream, as some online recipes suggest, turns a 24-Calorie cup into something closer to a snack.
Pair it with water. Broth is not a replacement for drinking water through the day.
Follow it with a real meal. Broth is a bridge, not a substitute for a meal with protein, vegetables and healthy fats.
Who should be careful?
Fasting is not right for everyone. Talk to your doctor before fasting if you have diabetes or take medication that affects blood sugar, if you are pregnant or breastfeeding, if you have kidney or heart conditions, if you are under 18, or if you have a history of disordered eating. If you have been advised to limit sodium, keep that in mind before adding broth to your morning.
The bottom line
Bone broth does break a fast in the strict sense. It is a small intake, about 24 Calories and 4.3g of protein a cup, and some people find it makes their planned routine easier. Decide based on your goal, and count broth as food rather than an energy-free drink. One plain cup can also be a simple way to begin your eating window.
Certified organic chicken bone broth powder, simmered 18+ hours in Byron Bay. One serve contains 24 Calories and 4.3g of protein.
Frequently asked questions
Does bone broth break a fast?
Strictly, yes, because it contains protein and energy. One cup of Byron Bay chicken broth has 24 Calories and 4.3g of protein.
Can I drink bone broth during 16:8 intermittent fasting?
Some people do, but it ends a strict fast. You can instead have it as the first food when your eating window begins.
How many calories are in a cup of bone broth?
One serve of Byron Bay Organic Chicken Bone Broth Powder made with 200ml of hot water contains 100kJ, or 24 Calories.
Is bone broth good for breaking a fast?
It is a traditional, light option. Some people start with a cup of warm broth before moving on to a full meal. Follow medical advice if you are fasting for health reasons.
Does bone broth affect ketosis or autophagy?
There is no good human research on this specific question. Claims that broth has no effect go beyond the evidence, and fasting does not guarantee these outcomes.
References
- de Cabo R, Mattson MP. Effects of intermittent fasting on health, aging, and disease. New England Journal of Medicine. 2019;381:2541–2551.
- Longo VD, Mattson MP. Fasting: molecular mechanisms and clinical applications. Cell Metabolism. 2014;19(2):181–192.
- Byron Bay Bone Broth. Organic Chicken Bone Broth Powder nutrition information panel. byronbaybonebroth.com. Accessed October 2026.
