The 21-Day Bone Broth Diet Explained
The 21-day bone broth diet is a regimen that alternates between periods of clean eating and modified fasting. Over the course of three weeks, participants consume five days of a Paleo-style diet and two non-consecutive days of mini-fasting with bone broth. The aim is to leverage the nutrient density of bone broth—rich in collagen, amino acids, and minerals—alongside intermittent fasting and clean eating principles to achieve health goals. The plan is designed to be manageable and straightforward, with clear guidelines on what to eat and what to avoid.
The Weekly Structure
The core of the 21-day bone broth diet involves a weekly cycle that is repeated for three weeks:
- Eating Days (5 days): These days follow a low-carb, Paleo-style eating pattern, focusing on whole, unprocessed foods. Meals consist of lean proteins, non-starchy vegetables, healthy fats, and some fruits, complemented by 1 to 3 cups of bone broth daily.
- Fasting Days (2 days): On two non-consecutive days, you consume only bone broth—typically five to six 8-ounce servings. Water, coffee, and herbal tea are also permitted. The timing of meals is also structured, with the last meal or snack typically consumed by 7 p.m..
Foods to Eat and Avoid
During the eating days, the diet emphasizes consuming whole, nutrient-dense foods while eliminating inflammatory or problematic ingredients.
Foods to Enjoy (Eating Days):
- Proteins: Grass-fed beef, pasture-raised chicken, wild-caught fish, and eggs.
- Vegetables: Non-starchy vegetables like leafy greens, broccoli, asparagus, and bell peppers.
- Healthy Fats: Avocado, olive oil, coconut oil, nuts, and seeds.
- Fruits: Berries, melons, apples, and other fruits in moderation.
- Beverages: Homemade or high-quality store-bought bone broth, water, herbal tea, and coffee.
Foods to Avoid (Initial 21 days):
- Grains and Gluten: This includes wheat, corn, rice, and oats.
- Dairy: No milk, cheese, or yogurt products.
- Legumes: Avoid beans, lentils, and peanuts.
- Sugar: All refined sugars, sugary beverages, and most sweeteners are restricted.
- Alcohol: All forms of alcohol are off-limits.
- Processed Foods: Eliminate packaged snacks, refined vegetable oils, and commercial sauces.
Potential Benefits and Risks of the Bone Broth Diet
While specific, peer-reviewed research on the 21-day bone broth diet is limited, studies on its components, such as intermittent fasting and the Paleo diet, and the nutritional properties of bone broth itself, can offer insights.
How the Diet Aims to Work
The potential benefits of the diet stem from a few key mechanisms:
- Weight Loss: The combination of low-calorie bone broth fasting and a reduced-carb, whole-foods diet naturally decreases overall calorie intake. The high protein and gelatin content in bone broth can also promote a feeling of fullness, which helps reduce snacking and overeating.
- Gut Health: The collagen and amino acids like glutamine in bone broth may help support and repair the intestinal lining, potentially reducing inflammation and addressing conditions like leaky gut syndrome.
- Reduced Inflammation: By eliminating processed foods, sugar, and other common inflammatory triggers, and incorporating anti-inflammatory foods, the diet may help lower systemic inflammation.
- Joint and Skin Health: The collagen found in bone broth may support joint function and improve skin elasticity, though more research is needed to confirm the extent of these effects.
Potential Risks and Concerns
- Nutrient Deficiencies: The elimination of major food groups like dairy and legumes can lead to deficiencies in essential nutrients like calcium, fiber, and B vitamins.
- Calorie Restriction: The fasting days involve consuming significantly fewer calories (around 600 kcal), which is well below the recommended intake for most adults. This can lead to fatigue, low energy, and poor athletic performance.
- Yo-Yo Dieting: The restrictive nature of the diet may make it difficult to sustain long-term, potentially leading to rebound weight gain and a cycle of yo-yo dieting.
- High Sodium Content: Store-bought bone broths can be high in sodium, which may pose a risk for individuals with high blood pressure, kidney disease, or heart disease.
- Limited Scientific Evidence: Many of the claims, particularly regarding significant weight loss and wrinkle reduction, are based on anecdotal evidence and have not been extensively studied specifically in the context of the 21-day diet.
A Sample Weekly Meal Plan
This sample plan illustrates the weekly structure of the 21-day bone broth diet, with two fasting days and five eating days. Always ensure you are well-hydrated throughout the diet.
| Day | Breakfast | Lunch | Dinner | Snacks | Notes |
|---|---|---|---|---|---|
| Monday | Scrambled eggs with sautéed spinach and avocado | Large salad with grilled chicken and olive oil dressing | Baked salmon with roasted asparagus and sweet potato | Bone broth (1 cup in afternoon) | Start the week with a full eating day. |
| Tuesday | Bone broth (1 cup) | Bone broth (1 cup) | Bone broth (1 cup) | Bone broth (2-3 additional cups) | A full mini-fast day. |
| Wednesday | Protein smoothie with berries, nut butter, and coconut milk | Roasted chicken breast with mixed greens and a vinaigrette dressing | Turkey meatballs in tomato sauce with zucchini noodles | Bone broth (1 cup) | Return to Paleo eating. |
| Thursday | Two poached eggs with sautéed mushrooms and a side of avocado | Leftover turkey meatballs | Ground beef stir-fry with broccoli and bell peppers | Bone broth (1 cup) | Focus on lean proteins and non-starchy veggies. |
| Friday | Bone broth (1 cup) | Bone broth (1 cup) | Bone broth (1 cup) | Bone broth (2-3 additional cups) | Second mini-fast day. |
| Saturday | Avocado and egg salad with fresh dill | Grilled steak strips over a bed of spinach with walnuts and berries | Pork chops with pan-seared Brussels sprouts and cauliflower rice | Bone broth (1 cup) | Whole-food eating day. |
| Sunday | Baked frittata with mixed vegetables and herbs | Leftover pork chops with vegetables | Chicken soup made with bone broth and shredded chicken | Bone broth (1 cup) | Nutrient-dense recovery day. |
Conclusion
The 21-day bone broth diet is a structured plan that leverages intermittent fasting and a Paleo-style, low-carb diet to promote weight loss, improve gut health, and reduce inflammation. While a 2025 open-label clinical trial found the diet to be safe and effective for weight loss in healthy adults with obesity, particularly with corresponding improvements in cardiometabolic and psychological health, it's essential to recognize the potential drawbacks. The diet is restrictive and may not be suitable for everyone, particularly those with underlying health conditions, a history of disordered eating, or high activity levels. Before beginning, consulting a healthcare professional is strongly recommended to ensure it aligns with your individual health needs. For those with digestive sensitivities, seeking low-FODMAP bone broth can make the diet more manageable. The principles of incorporating whole foods and reducing processed foods, however, can be adopted more broadly for long-term health benefits, with or without the strict fasting schedule.
