The bone broth diet has gained popularity as a simple intermittent fasting regimen that promises weight loss and other health benefits. This article delves into the details of the 21-day bone broth diet, exploring its potential benefits, risks, and what you can realistically expect in terms of results.
Understanding the Bone Broth Diet
The 21-day bone broth diet is a type of intermittent fasting (IF) program called 5:2. Generally speaking, intermittent fasting is the practice of taking regular breaks from food. The 21-day bone broth fast was popularized by Dr. Kellyann Petrucci-an author and naturopath-as a way to detox your body, lose weight, and heal your gut.
How it Works
The bone broth diet plan alternates between a Paleo diet five days a week followed by two days of fasting and drinking a lot of bone broth every day. This regimen includes one to three servings of bone broth each day, combined with a diet rich in whole, unprocessed foods five days a week.
On two non-consecutive days a week, followers are intended to do a modified fast, drinking five to six 8-ounce servings of bone broth throughout the day. The other five days are based on an anti-inflammatory paleo diet (ideally within an 8-hour eating window), consisting of protein, non-starchy veggies, and healthy fats.
The Paleo Connection
When you eat paleo, you avoid grains, refined foods, sugar, alcohol, legumes, and (sometimes) dairy. The paleo diet, in fact, is rather similar to a whole foods ketogenic diet. The truth is, paleo and keto diets aren’t so different. The paleo diet allows more carbs, and sometimes disallows dairy - but both diets prohibit the processed junk that plagues the Standard American Diet. A bone broth fast is perfectly compatible with a whole foods ketogenic diet. The bone broth days stay the same.
Read also: Bone Broth Benefits with Miracle Noodle
What to Eat and Avoid
Foods to Eat
On fasting days, you’re recommended to drink six 8-ounce servings of bone broth as well as water, herbal tea, and coffee. On non-fasting days, you follow a minimally processed, anti-inflammatory diet consisting of three meals a day and one to three cups of bone broth.
The bone broth diet encourages high-quality animal proteins (like chicken, beef, and fish), non-starchy vegetables (like broccoli, asparagus, spinach, and mushrooms), and healthy fats (like avocado, nuts, flaxseed, and olives). Smaller amounts of starchy vegetables like sweet potatoes, green peas, winter squash, and carrots are also permitted. Milk alternatives, fruit, and natural sugar substitutes such as agave, date sugar, and honey are also allowed in moderation.
Plate Blueprint:
- ½ non-starchy veggies
- ¼ lean protein
- ¼ healthy fat
Foods to Avoid
On non-fasting days, followers should avoid grains, bread, legumes, peanuts, dairy, refined sugars, sugary beverages, refined vegetable oils, commercial sauces and condiments, alcohol, and all processed foods. On the two fasting days, all food is off limits, and you can only consume bone broth, water, herbal tea, and coffee.
During the initial 21-day diet, you must avoid certain foods and beverages, including all grains, dairy, legumes, added sugars, and alcohol.
Potential Benefits of the Bone Broth Diet
Bone broth seems like a jack of all trades when it comes to health benefits. Thanks to the natural collagen, minerals, and amino acids, there are some rewards to regularly drinking bone broth. "Bone broth can help repair the gut lining, support joint health, improve skin elasticity, and it can offer a great source of hydration."
Read also: Benefits and Risks of Bone Broth Diet
Weight Loss
One of the primary reasons people try the bone broth diet is for weight loss. Drinking only bone broth can help you lose weight because it deprives you of calories. Bone broth has almost no carbohydrates and is low in calories. "Bone broth is low in calories ranging between 40 to 50 calories per eight ounces and provides about one serving of protein per cup (8 to 10 grams)." High protein foods and non-starchy vegetables are also known to reduce overeating and limit the desire to snack between meals which may support weight loss.
However, there’s no scientific research on actual weight loss results while on the bone broth diet, but calorie restriction is a big reason why you might lose weight. Any weight loss may be short-term, and rebound weight gain is likely. "Sure, you could see weight loss during the 21 days of dieting, but once those 21 days are over, you may feel deprived from eliminating so many foods that you result to binge eating which can then lead to weight gain," as can be the case with any short-term diet plan. "This can then lead to a vicious cycle of yo-yo dieting which is detrimental to metabolism, weight gain, and gut health, and can lead to an increased risk of chronic disease."
Gut Health
The amino acids in bone broth may also improve the barrier of your intestinal barrier, reduce inflammation, protect against chronic inflammatory diseases, and improve overall gut health, per 2025 research in Digestive Diseases and Sciences. The gelatin protein in bone broth fills up the stomach and keeps you fuller for longer. You may receive the advantages of an intermittent fast while still feeling full. The amino acids in bone broth, particularly glutamine, help repair the intestines.
Skin Health
When your skin collagen breaks down, it shows up as wrinkles, fine lines, and other signs of aging. Taking collagen may provide the raw materials to offset this decline.
Joint Support
NSAIDs (non steroidal anti inflammatory drugs) are the standard treatment for chronic joint pain, but these medicines have bad side effects. Enter collagen.
Read also: Bone Broth Fasting: A Detailed Look
Other Potential Benefits
You may also notice improved sleep, reduced cravings, weight loss, increased energy levels, and less inflammation. "The validity of some of these claims can be attributed to individual components of the diet. For example, eating foods like salmon and dark leafy greens can help reduce inflammation, consuming adequate protein throughout the day can help reduce cravings and promote fat loss, and collagen, glucosamine, and chondroitin are nutrients that can be found in bone broth and may improve joint health."
Risks and Considerations
The bone broth diet claims to come with a slew of health benefits, but that doesn’t mean it’s for everyone. The bone broth diet is restrictive, so there are inherently some risks. "During those two days of bone broth fasts, you’re only consuming about 600 calories which is significantly below the recommendation for any living human."
The diet is also low in carbohydrates which are crucial for energy and overall health. That also means it’s likely low in fiber which can wreak havoc on your gut causing constipation, bloating, gas, and hemorrhoids. Not to mention, any diet that severely restricts calories or entire food groups increases the risk of nutritional deficiencies. For example, completely eliminating dairy can put you at risk of a calcium deficiency. On the flip side, consuming too much of a nutrient can also pose risks. For example, bone broth can be high in sodium and potassium which may be dangerous for those with kidney disease, liver disease, or high blood pressure.
Who Should Avoid the Bone Broth Diet?
Since intermittent fasting is a factor, the diet is not recommended for anyone who is pregnant or nursing, immunocompromised, or diabetic. Those with a history of disordered eating should also steer clear. "Any diet that eliminates food groups or categorizes foods as ‘good’ or ‘bad'-or in this case, ‘yes’ or ‘no’-is likely to foster an unhealthy relationship with food because eating a ‘disallowed’ food can result in feelings of guilt and shame.” Such feelings can then lead to further restriction and/or binging.
The bone broth diet is not ideal for athletes or anyone with a moderate- to high-intensity workout schedule-even if your goal is weight loss. Your body needs carbohydrates to refuel post-workout, and the low-carb nature of the diet can lead to poor performance, fatigue, and an increased risk of injury.
Making Bone Broth
If you have time, you can make bone broth at home. Bone broth is prepared by boiling the bones and connective tissue of animals, such as beef, lamb, fish, or chicken.
The diet encourages you to make your own bone broth - preferably using bones from organic, pasture-raised animals. It recommends using knuckle, joint, feet, and neck bones since they’re rich in cartilage. This source of collagen is the basis for the diet’s claim of erasing wrinkles.
Scientific Evidence and Studies
To be clear, a bone broth intermittent fast hasn’t been tested in the lab. Currently, no studies published in scientific journals exist for the Bone Broth Diet.
Kellyann Petrucci, author of books about the diet, set up three unpublished 21-day studies run by different health professionals. She reports the participants “lost up to 15 pounds and up to 4 inches in their measurements.” However, Petrucci didn’t report average weight loss, nor did she compare the Bone Broth Diet to a standard reduced-calorie diet. Furthermore, it’s unknown whether the participants kept off the weight. No other studies have looked at whether bone broth helps promote weight loss.
This leaves gaps in the evidence needed to determine whether the Bone Broth Diet is as effective or superior to other weight loss diets as Petrucci claims.
However, the diet is based on other approaches that have been studied:
- Low-carb: Low-quality scientific reviews of low-carb diets suggest they produce 1.5-9 pounds (0.7-4 kg) more weight loss than standard reduced-calorie diets. However, high-quality reviews report little or no difference between diets.
- Paleo diet: In a three-week study, healthy-weight people on a paleo diet lost 5 pounds (2.3 kg) and 1/4 inch (0.5 cm) from their waistline. Other studies report no difference between paleo and standard reduced-calorie diets.
- Intermittent fasting: In a review of five studies, two showed greater weight loss in overweight people using intermittent fasting compared to continuous calorie restriction, while three showed similar weight loss with each method.
Thus, a combination of these three dietary approaches - such as in the Bone Broth Diet - may help you lose weight. However, standard reduced-calorie diets may work just as well.