How the Carnivore Diet Undermines Your Thyroid Health
Reproduced from original article:
https://articles.mercola.com/sites/articles/archive/2025/11/09/how-carnivore-diet-undermines-thyroid-health.aspx
Analysis by Dr. Joseph Mercola November 09, 2025
Story at-a-glance
- Cutting out carbohydrates on a carnivore diet starves your thyroid of glucose, slowing the conversion of the inactive thyroid hormone T4 into the active hormone T3 and leaving you tired, cold, and struggling with weight gain
- Fresh meat contains glycogen that supplies some carbs, but aged meat loses this benefit and builds up endotoxin, which disrupts metabolism and fuels inflammation
- Eating only muscle meat overloads you with amino acids that suppress thyroid hormone production and throws off calcium-to-phosphorus balance, creating long-term stress on your metabolism
- Excess iron storage is common in carnivore eaters, and high ferritin combined with oxidative stress damages your mitochondria, further weakening thyroid-driven energy production
- Restoring thyroid health requires reintroducing healthy carbs, lowering excess iodine intake, reducing iron overload, balancing protein with collagen and calcium, and supporting adrenal-thyroid balance with progesterone
Thyroid problems are far more common than most people realize, and the consequences go well beyond fatigue or weight gain. This small gland sits at the center of your metabolism, regulating how every cell in your body produces energy. When it falters, the ripple effects touch your mood, digestion, fertility, and even your long-term risk of serious disease.
What often gets overlooked is how much your daily food choices influence thyroid health. The nutrients you eat — or don’t eat — determine whether your body produces enough active thyroid hormone to keep you warm, energized, and mentally sharp. Diets that cut out entire food groups, especially carbohydrates, set the stage for a slow decline in thyroid function and leave you relying on stress pathways to get through the day.
This raises an important question: what really happens when you remove carbs altogether and rely only on meat for fuel? To answer that, you need to understand how the carnivore diet interacts with your thyroid and why it places your metabolism under strain.
Why Carnivore Eating Harms Thyroid Health
In a discussion on Jay Feldman’s The Bioenergetic View Podcast, bioenergetic researcher Georgi Dinkov and colleagues examined holistic nutritionist Judy Cho’s claims that low thyroid markers in her carnivore clients were not caused by the diet itself.1
They challenged this view by pointing out that thyroid suppression is directly linked to a lack of carbohydrates in the diet. Your body’s ability to convert the inactive thyroid hormone T4 into the active hormone T3 depends on glucose, which fresh meat provides in small amounts through glycogen but which is lost as meat ages.
• The difference between fresh and aged meat is central to this argument — Freshly killed meat still contains glycogen, a stored form of carbohydrate found in muscles and liver. Eating this meat means you’re consuming both protein and carbs, often close to a one-to-one ratio.
However, once meat ages, bacteria ferment the glycogen into lactic acid. This process removes the carbohydrate benefit and leaves you with only protein, higher levels of endotoxin, and compounds that stress your metabolism.
• Aged meat changes your hormonal balance — With glycogen gone, your liver lacks the glucose needed to activate thyroid hormones. This forces your body to fall back on stress responses, raising cortisol and glucagon to keep blood sugar stable. Over time, this stress-driven energy system wears down your thyroid, leaving you fatigued, cold, and more prone to weight gain, even when you think you are eating healthy.
• The amino acid profile of meat adds another layer of stress — Dinkov highlighted that muscle meats are loaded with amino acids that directly suppress thyroid hormone production. That means the very foods you rely on to heal your metabolism are actually interfering with your thyroid’s ability to produce T4. Without balancing these proteins with gelatin, collagen, or calcium, you create a hormonal environment that works against you.
• The calcium-to-phosphorus ratio in meat is heavily skewed — High phosphorus intake without enough calcium leads to long-term pro-aging effects on metabolism. This imbalance slows your metabolic rate further and makes you vulnerable to conditions like osteoporosis and muscle weakness. To correct this, add gelatin or calcium carbonate to ground meats — what Dinkov called a “Bulgarian burger” — to restore balance and support energy production.
• Eating only meat forces your body to make sugar out of protein instead of using carbs — This backup process drains energy and pushes up stress hormones like cortisol. Dinkov explained that after a big meat-heavy meal, he often felt cold, which shows low blood sugar and a slowed thyroid. But when he added carbs along with the meat, his temperature and energy went up quickly.
Lack of Carbohydrates Leads to Thyroid Decline
While Cho claimed that environmental factors or stressors explained her clients’ thyroid issues, Dinkov disagreed. He explained that the lack of carbohydrates is the simplest, most direct reason thyroid markers decline on carnivore diets. As health coach Mike Fave put it, “Your hormonal function is dependent on carbohydrate.”2 Ignoring this leads to denial and “mental gymnastics,” Feldman explained, that obscure the obvious.3
• The lack of fiber in carnivore eating adds to the problem — Without fiber, gut bacteria shift toward more inflammatory patterns. This increases endotoxin load in your body, which interferes with thyroid hormone function and further suppresses energy production. Endotoxin is a bacterial byproduct that spreads from your gut into your bloodstream, fueling systemic inflammation.
In the context of a thyroid already under stress, this combination is especially damaging. Just be aware of the fiber paradox: fiber is necessary, but if you consume it when your gut is unhealthy, it makes symptoms worse. So always heal your gut health before adding beneficial fiber to your diet.
• Iron overload is another hidden risk of carnivore diets — Many long-term carnivore eaters develop high ferritin and iron saturation levels, which promote oxidative stress. When stored iron interacts with polyunsaturated fats like linoleic acid (LA) already in your tissues, it sparks harmful free radical reactions that damage your mitochondria — the engines of your cells. This weakens thyroid-driven metabolism even further and accelerates aging.
• Revisiting lost medical knowledge about thyroid care — Older medical texts once recommended high-carbohydrate, moderate-protein, low-fat diets to boost thyroid function. Doctors at the time understood that your metabolism and thyroid health depended on having enough carbohydrates. That perspective changed when the “rate of living theory” took hold in the mid-20th century.
This theory claimed that the faster your metabolism ran, the shorter your lifespan would be, so lowering metabolic rate was promoted as beneficial. This shift in thinking opened the door for low-carb diets and helps explain why obesity and thyroid problems have become so widespread today.
• Real-world signs of low thyroid were tied back to diet — The panel described how some patients on carnivore diets had high lab values for testosterone but still suffered from low energy, poor libido, and hypogonadal symptoms. This mismatch was explained by high levels of a protein that locks away testosterone, making it unavailable for use. These patterns reflect disrupted metabolism, not unrelated stressors as Cho suggested.
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How to Protect Your Thyroid if You’ve Tried the Carnivore Diet
If you’ve been eating only meat and notice cold hands, stubborn weight gain, or low energy, your thyroid is under pressure. The problem isn’t discipline — it’s the lack of healthy carbohydrates, the overload of certain amino acids, and the mineral imbalances that come with carnivore eating.
Your thyroid depends on glucose to function properly, and starving it of carbs slows your metabolism and drives up stress hormones. The good news is you can repair this by restoring balance, lowering stress signals, and giving your thyroid what it actually needs.
1. Prioritize healthy carbohydrates every day — A balanced diet rich in the right carbs — and free of ultraprocessed foods — feeds your mitochondria with the glucose they’re designed to burn. If you’ve been eating low-carb or carnivore, you’ve been starving those engines, which slows healing and drains your energy.
Focus on whole fruits and white rice first, then gradually bring in root vegetables, legumes, and well-tolerated grains as your gut improves. Aim for 250 grams of healthy carbs daily to keep your thyroid working at full capacity.
2. Reduce iodine overload — Getting too much iodine is a major cause of thyroid dysfunction, and cutting back often restores normal thyroid activity within months. Processed grains are among the biggest culprits.
Keeping iodine intake modest — below 200 micrograms per day — protects you from tipping your thyroid into overdrive or autoimmunity, especially if you have a family history of thyroid disease. If you’ve struggled with unexplained thyroid symptoms, lowering iodine is one of the most effective steps you can take.
3. Address iron excess before it damages your thyroid — Excess iron is a hidden thyroid saboteur. If you don’t know your ferritin level, that’s the first test to request — healthy levels are between 60 and 75 ng/mL.
High ferritin means your body is storing too much iron, which leaks into tissues and your brain, fueling oxidative stress that disrupts thyroid hormone function. Pair this with a gamma-glutamyl transferase (GGT) test, which measures oxidative stress, to confirm if stored iron is actively harming your metabolism.
If both ferritin and GGT are high, your thyroid is already under attack. The fix is straightforward — donate blood two to four times a year to pull iron out of storage, or request therapeutic phlebotomy if blood donation isn’t an option. This step protects your thyroid by lowering the oxidative stress that blocks energy production.
4. Balance protein with collagen and calcium — Eating only muscle meat floods your body with amino acids that suppress thyroid function and leaves you short on calcium. To correct this, mix in collagen, gelatin, or tougher cuts with connective tissue. Adding calcium carbonate or eggshell powder to meals helps restore the calcium-to-phosphorus ratio, which keeps your metabolism stronger over the long term. Think of it as building thyroid-friendly meals instead of just eating steak alone.
5. Support hormonal balance with progesterone — Your adrenal glands work hand in hand with your thyroid, and progesterone is key to keeping both systems in balance. Without enough progesterone, adrenal stress rises, dragging down thyroid function. Natural progesterone supplementation helps stabilize your hormones, calm anxiety, improve sleep, and restore energy. Incorporating progesterone into your routine is a powerful way to strengthen the entire thyroid-adrenal system.
FAQs About the Carnivore Diet and Thyroid Health
Q: Why does the carnivore diet harm thyroid health?
A: The carnivore diet cuts out all carbohydrates, which your thyroid needs to convert the inactive hormone T4 into the active hormone T3. Without enough glucose from carbs, your body relies on stress hormones like cortisol to maintain energy, which wears down thyroid function over time.
Q: Does eating fresh meat protect thyroid health compared to aged meat?
A: Fresh meat still contains glycogen, a stored form of carbohydrate, so it provides some glucose along with protein. Aged meat loses this glycogen and becomes high in endotoxin, which disrupts metabolism and increases stress on your thyroid.
Q: How does iron overload affect my thyroid?
A: High ferritin, the storage form of iron, causes oxidative stress that damages mitochondria and blocks thyroid hormone function. Testing both ferritin and GGT reveals if stored iron is harming your metabolism. If your levels are high, donating blood or requesting therapeutic phlebotomy helps lower iron and protect thyroid activity.
Q: What role do healthy carbohydrates play in thyroid recovery?
A: Carbohydrates are your body’s preferred source of glucose, the fuel your thyroid relies on to activate hormones. Whole fruits, white rice, root vegetables, legumes, and well-tolerated grains provide steady energy that keeps your metabolism strong. Aiming for about 250 grams daily supports optimal thyroid health.
Q: Which additional steps support thyroid function beyond diet?
A: Balancing muscle meat with collagen and calcium corrects nutrient imbalances that suppress thyroid activity. Reducing excess iodine intake prevents thyroid overstimulation, while natural progesterone supplementation stabilizes hormones, lowers stress, and improves sleep — all of which reinforce thyroid health.