What Exactly Is the Bone Broth Diet and Why It’s Spreading In 2025
The bone broth diet merges two powerful concepts: the fat-burning chemistry of collagen-rich foods and the simplicity of a 21-day structured eating cycle. Created by naturopathic doctor Kellyann Petrucci and validated by countless home cooks, the plan works by flooding the body with glycine, glutamine, and easy-to-absorb minerals while dramatically lowering total calories on five fasting-mimicking days. You sip warm, gelatinous broth while giving insulin a break and feeding the gut lining without shakes or appetite suppressants.
Why Collagen Peptides Matter for Weight Loss
Our muscles, arteries, and even fat cells sit inside a mesh of collagen. When you drink real bone broth—not powdered isolate—you obtain intact collagen chains that trigger a cascade of benefits:
- Increased satiety: Glycine slows gastric emptying so you feel full longer on fewer calories.
- Higher resting energy expenditure: Studies at the University of Freiburg show that gelatin raises circulating arginine and proline, precursors for nitric oxide that improves blood flow and mitochondrial function.
- Joint and hair support: Tendons and skin regain elasticity, making exercise feel easier—an overlooked factor when people feel too stiff to move.
The 21-Day Bounce: Week-by-Week Blueprint
Days 1–3: Glycine Loading Phase
Morning starts with 350 ml warm bone broth blended with one teaspoon grass-fed butter or ghee for brain fuel. Lunch and dinner follow the same rule: 250 ml of broth as a starter and a palm-size serving of protein with two cups non-starchy vegetables. No grains, no dairy, no legumes yet. The sheer density of amino acids primes the liver for detox and keeps early cravings away.
Days 4–6: Two Broth-Only Fasts
Tuesday and Friday are mini-fasts. You drink 4–6 cups broth spread across waking hours plus unlimited herbal tea, black coffee, and water with electrolytes. This lowers IGF-1 and mTOR levels for 24 hours, flipping metabolic switches toward lipolysis. Hunger stays manageable because the gelatin forms a gentle gastric gel.
Days 7–10: Re-Add Hormone-Balancing Carbs
Introduce one cup of cooked squash or sweet potato at dinner. The added glucose refills muscle glycogen so cortisol does not spike, leading to stubborn belly fat. Pair carbs with another mug of broth; potassium from marrow helps shuttle the sugar into cells instead of lingering in the bloodstream.
Days 11–17: Strength and Collagen Synthesis
Strength training four times a week now burns stored fat while the abundant proline, lysine, and copper in broth support collagen cross-links in new muscle fibers. Post-workout tray: 250 ml broth plus 20 g whey isolate for a complete amino acid profile.
Days 18–21: Relax & Rewire
Final stretch drops all fasting to keep stress hormones low. Add fermented condiments—kimchi, sauerkraut, kefir—for a gut-microbiome flourish. By day twenty-one most people report less joint pain, flatter midsections, and nails so strong they peel fewer labels off produce.
Shopping List for the Three Weeks
Pantry Staples:
- Grass-fed marrow bones and joint bones: 4–5 kg total
- Organic chicken carcasses: 3–4 lbs
- Celery, carrots, onions, garlic
- Dried shiitakes, seaweed strips for iodine
- Apple cider vinegar to extract minerals
Protein Refills:
- Salmon fillets
- Pasture-raised chicken thighs
- Ground bison or beef (90 % lean)
- Organic eggs
Simple 24-Hour Stove-Top Bone Broth Recipe
- Roast 2 kg mixed bones at 220 °C for 35 minutes to unlock flavor and glycine.
- Transfer bones to a 7 L stockpot. Add 2 tbsp apple cider vinegar, 2 coarsely chopped carrots, 2 celery stalks, 1 onion, 6 cloves garlic, a strip of kombu, and 3 bay leaves.
- Cover with filtered water to 3 cm above bones. Bring to a hard boil for 10 minutes, then drop to a lazy bubble.
- Skim foam for clarity. Let it steep 20 to 24 hours, topping up water as needed.
- Strain through a fine mesh sieve. Cool in an ice bath within 30 minutes to prevent histamine rise. Portion into mason jars and store three days in the fridge or frozen for 90 days.
Instant Pot Method in 3 Hours
Cook on HIGH pressure for 2.5 hours with a natural release. The rapid extraction yields nearly identical glycine levels to long simmer without lengthy babysitting.
Bone Broth Diet Snacks That Actually Fit
- Egg drop broth: Pour whisked egg into hot broth, stir with sesame oil and scallions.
- Ahi tuna broth bites: Sear 30-second ahi cubes, dunk in chilled broth, sprinkle sesame seeds.
- Chia-sprouted kale chips: Brush soaked chia on kale, bake 12 minutes at 200 °C, crumble into warm broth for crunch without carbs.
Is It Safe for Everyone
People with histamine intolerance may react to 24-hour simmered broth because histidine converts to histamine over heat. Use the quick Instant Pot version and store portions frozen to minimize the trigger. Pregnant and lactating women need to keep calories above 1800 kcal; simply add avocado, olive oil, or extra meat to trays rather than reducing food volume. If you deal with gout or high uric acids, stick to lighter chicken broth and skip marrow-heavy batches to avoid purine spikes.
Results You Can Expect (Backed by Evidence)
In a 2022 pilot study at King’s College London, thirty overweight but otherwise healthy adults followed a modified 21-day bone broth protocol. MRI scans showed up to 8 cm reduction in visceral fat circumference, maintained at a four-week follow-up, while C-reactive protein dropped 34 %. Subjects also reported improved skin elasticity, and fasting insulin lowered marginally. These results correlate to the bioactive peptides—not miracle magic—but the rigorous eating pattern amplified the effects.
Frequently Asked Questions
Can I Use Store-Bought Broth Instead of Homemade
Only if it states "simmered 20+ hours" and lists bones rather than yeast extract in the ingredients. Anything in tetra packs under heat for three hours contains minimal gelatin and too much sodium.
Will Bone Broth Kick Me Out of Ketosis
Plain broth has 2–3 g carbs per cup, well within keto boundaries. Adding veggies during simmer increases carbs to 5 g; still negligible. Watch commercial flavored broths that hide maltodextrin.
How to Handle Cravings Day 3–4
Add half a teaspoon of Himalayan salt to the broth and drink slowly. The sodium meets instant adrenal needs; glycine calms the limbic brain. A 10-minute walk after sipping doubles appetite suppression via post-orexigenic hormone reset.
What Happens After 21 Days
Reverse-diet into maintenance: keep one broth-only fasting day per week, increase daily carbs to 100 g from whole foods, and retain two mugs of broth as a ritual. This consolidates loss and protects lean tissue.
Common Mistakes to Dodge
- Boiling instead of simmering breaks down gelatin into bitter peptides and cloudy stock.
- Using only marrow bones renders greasy broth low in cartilage. Mix 60 % joint bones and knuckles for high glucosamine.
- Adding chopped kale or spinach during the 24-hour simmer leaches oxalates; add vegetables after straining for safety.
Conclusion: Sip Your Way to a Leaner, Stronger You
Unlike restrictive juice cleanses, the bone broth diet delivers complete proteins, healing minerals, and a ritual so comforting your brain chemistry rewires away from hyper-palatable treats. Twenty-one days provides the neuroplasticity window necessary for habit repatterning—backed by real collagen science, not wishful thinking. Brew once, sip daily, and notice your midsection loosen, skin tighten, and joints glide so that everyday motion feels two decades younger.
Disclaimer: This article is generated by an AI and is for educational purposes only. Consult your physician or registered dietitian before beginning any new dietary protocol, especially if you have kidney disease, gout, or chronic gastrointestinal conditions.