Does Bone Broth Break a Fast?

Short answer: Yes, technically. A cup of store-bought bone broth usually has 40 to 50 calories and about 9 to 10 grams of protein, based on labels in USDA FoodData Central [5][6][7]. That breaks a clean, zero-calorie fast. On a flexible plan, or on a 5:2 day with a calorie budget, a cup can still fit.

In PingDiet terms, a mug of bone broth is a Ping. It's a small one, but it's food: protein, a little fat, and a fair amount of salt. That makes it different from the squeeze of lemon in our lemon water guide, which adds only a few calories.

Who should skip fasting: Johns Hopkins Medicine says intermittent fasting isn't for children and teens under 18, people who are pregnant or breastfeeding, people with type 1 diabetes who take insulin, or anyone with a history of eating disorders, and that everyone should check with a doctor before starting [11]. This page is general information, not medical advice.

How many calories are in bone broth?

Most cartons land between 15 and 50 calories a cup, but the range is wider than people expect. We pulled the label data for eight broths from USDA FoodData Central, and the highest had more than seven times the calories of the lowest.

The two USDA rows are standard reference foods (SR Legacy), which we converted to a cup [1][2]. The brand rows are label values from USDA's Branded Foods data, published there in 2022 and 2023 [4][5][6][7][8][9]. Recipes change, so check the carton in your hand.

Two things stand out. Regular broth is mostly flavored salt water, while bone broth carries real protein. And the Wegmans carton, which lists only water and organic chicken bones, has about twice the protein of the typical bone broth [8]. Homemade beef stock in the USDA data comes in lower than chicken, at about 31 calories and 5 grams of protein a cup [3].

Does it depend on how you fast?

Yes. Whether bone broth "breaks" your fast comes down to the rules you're following.

A clean intermittent fast (16:8, 18:6, OMAD). Johns Hopkins lists water and zero-calorie drinks such as black coffee and tea for the fasting hours [11]. Bone broth isn't on that list. If you want a warm drink that keeps the fast clean, black coffee or plain tea is the swap, and our coffee guide covers what you can add.

A flexible fast. Some people allow a small amount of food and mainly care about pushing their first real meal later. A cup of broth can make that easier. Just count it as the start of your eating, not as part of the fast.

The 5:2 approach. Johns Hopkins describes two days a week of one 500 to 600 calorie meal [11]. A 45-calorie cup of broth fits inside that budget without much trouble.

Fasts longer than a day. Johns Hopkins says 24- to 72-hour fasts aren't necessarily better and may be dangerous [11]. A "bone broth fast" where you drink several cups a day is really a very low-calorie diet. Talk to your doctor before trying one.

A fasting blood test. No broth. MedlinePlus says fasting for a blood test means nothing but plain water [12]. Follow the instructions your provider gives you.

Does bone broth raise insulin?

Probably a little, because it contains protein, but we couldn't find a study that measured insulin after a cup of bone broth itself. What we found were studies on the same kind of protein.

Bone broth is sold as a source of collagen, the protein that turns into gelatin when bones and connective tissue simmer [13]. Researchers at the Minneapolis VA Medical Center wrote that gelatin is the most potent protein for boosting insulin when it's eaten with glucose, and that it's about 30% glycine [14]. In their 2002 study of nine healthy people, glycine on its own raised insulin slightly [14].

A 2025 trial in 15 active women found that 15 grams of collagen peptides after a workout raised insulin about 80% at its peak, compared with a drink with no calories [15]. Two of the authors work for a collagen maker. Most cartons in our table have less protein than that, 4 to 10 grams a cup [4][5][6][7].

So a cup of broth isn't the same as a sugary drink, but it isn't neutral either. If keeping insulin low is the point of your fast, save it for your eating window.

Does bone broth kick you out of ketosis?

We found no study that measured ketones after bone broth, so we won't guess. What the labels show is that most cartons have 0 to 1 gram of carbohydrate per cup [4][5][6][7].

Watch for two exceptions. Homemade chicken stock in the USDA data has about 8.5 grams of carbohydrate a cup, mostly from the vegetables simmered in it [2]. And some broth concentrates use maltodextrin, a starch: one beef bone broth concentrate lists 7 grams of carbohydrate per serving [10].

The same goes for autophagy, the cell clean-up process that fasting gets linked to online. We found no human study that measured it after bone broth. Claims that a cup stops it, or doesn't, are guesses.

How much bone broth can you drink without breaking a fast?

If your rule is zero calories, none. There's no amount of food that keeps a clean fast clean.

You'll see a "50-calorie rule" online, but we found no study that set that line. It's a rule of thumb, not a measured switch. If you use it anyway, one cup of most cartons in the table sits right at it, and a second cup doesn't.

One thing that can make the numbers look smaller than they are: FDA rules round calories on a label to the nearest 5 up to 50, and to the nearest 10 above that [17]. That's fine for one cup, but it adds up if you sip all day.

How much sodium is in bone broth?

A lot, compared with most drinks. The cartons in our table list about 260 to 480 milligrams of sodium per cup, the LonoLife stick lists 584 mg, and regular ready-to-serve chicken broth in USDA data has about 920 mg [1][4][5][6][7][8][9].

For context, the Dietary Guidelines for Americans recommend that adults keep sodium under 2,300 mg a day, according to the FDA [16]. Two or three cups of salty broth can use up a big share of that before you've eaten a meal.

That salt is also why people on longer fasts reach for broth. If that's you, our guide to electrolytes while fasting covers sodium, potassium and magnesium, and when they matter.

Is bone broth a good source of collagen?

Not a reliable one. A 2019 study by researchers at the Australian Institute of Sport and Australian Catholic University tested commercial, café-made and homemade bone broths for the amino acids that make up collagen [13]. Broths made to a standard recipe had much less than a 20-gram dose of a collagen supplement, and the amounts varied a lot between non-standard recipes. Café broths had the most, and when everything was made to the same recipe, commercial broths had less than homemade ones.

So enjoy broth for its flavor and protein, but don't count on a set amount of collagen per cup. If you're weighing collagen powder instead, our supplements and fasting table explains why it's an eating-window item too.

How to fit bone broth into a fasting schedule

1. Make it your first Ping. A cup at the start of your eating window counts as eating, so start your eating clock there. The eating window calculator works out your hours from any start time.
2. Pick by the label, not the front of the carton. Look for protein, sodium and carbohydrate per cup. If you buy cartons often, a low-sodium bone broth leaves you more room for salt in your meals.
3. Use powder for travel or work. Single-serve bone broth powder stick packs are easy to carry. Check them for maltodextrin or added sugar, and paste the panel into our label checker if you're unsure.
4. Skip it before a fasting blood test. Plain water only [12].
5. Keep the fasting hours clean. Water, black coffee or plain tea are the zero-calorie options [11].

Where bone broth fits next to other fasting drinks

Bone broth sits at the "real food" end of the fasting drink list. Lemon water adds a few calories, plain creatine lists none, and broth adds 15 to 110 depending on the carton. Our guides to lemon water, creatine and supplements cover the rest.

If you're still picking a schedule, our 16:8 vs 18:6 vs OMAD comparison lays out the trade-offs, and the OMAD guide shows how one meal a day works. For more drinks and add-ins, see the full What Breaks a Fast section.

Photos: top, Piotr Arnoldes, Pexels; above, Denniz Futalan, Pexels

Sources

1. USDA FoodData Central. Soup, chicken broth, ready-to-serve (FDC 174536), SR Legacy
2. USDA FoodData Central. Soup, stock, chicken, home-prepared (FDC 172884), SR Legacy
3. USDA FoodData Central. Soup, stock, beef, home-prepared (FDC 172883), SR Legacy
4. USDA FoodData Central. Zoup! Chicken Bone Broth (FDC 2667433), Branded Foods
5. USDA FoodData Central. Imagine Chicken Bone Broth (FDC 2677839), Branded Foods
6. USDA FoodData Central. College Inn Beef Bone Broth (FDC 2561841), Branded Foods
7. USDA FoodData Central. Kitchen Basics Bone Broth, Chicken, Original (FDC 2626497), Branded Foods
8. USDA FoodData Central. Wegmans Chicken Bone Broth (FDC 2655319), Branded Foods
9. USDA FoodData Central. LonoLife Chicken Bone Broth, stick pack (FDC 2285602), Branded Foods
10. USDA FoodData Central. Sam's Choice Concentrate Bone Broth, Beef (FDC 2328175), Branded Foods
11. Johns Hopkins Medicine. Intermittent Fasting: What Is It, and How Does It Work? Updated April 7, 2026
12. MedlinePlus, National Library of Medicine. Fasting for a Blood Test
13. Alcock RD, Shaw GC, Burke LM. Bone broth unlikely to provide reliable concentrations of collagen precursors compared with supplemental sources of collagen used in collagen research. Int J Sport Nutr Exerc Metab. 2019;29(3):265-272
14. Gannon MC, Nuttall JA, Nuttall FQ. The metabolic response to ingested glycine. Am J Clin Nutr. 2002;76(6):1302-1307
15. Reynolds KM, et al. The effects of collagen peptide supplementation on appetite and post-exercise energy intake in females: a randomised controlled trial. Br J Nutr. 2025;134(4):265-276
16. U.S. Food and Drug Administration. Sodium in Your Diet
17. U.S. Code of Federal Regulations. 21 CFR 101.9(c)(1), Nutrition labeling of food