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Weight Loss

Explained: The Link Between Hashimoto’s, Low Thyroid, and Weight Gain (and How to Fix It)

Your diet can help.


Did you know that a sneaky thyroid slowdown sometimes doesn’t show up on blood work? If you’re experiencing symptoms like unexplained weight gain, you may want to get your thyroid checked. Dr. Emi Hosoda healed her own gland and dropped 100 pounds at age 50 — her plan might work for you, too.

Dr. Emi Hosoda, 53, Enumclaw, WA, lost 100 lbs

“At 100 pounds overweight, I was doing all the things people tell you to do: I limited myself to 1,200 calories a day and hiked up a mountain for exercise. Yet my weight would not budge,” recalls internist Emi Hosoda, MD, 53. She also suffered from fatigue, brain fog, cold sensitivity, and hair loss, though thyroid tests came back “normal.” She figured, “My demanding life had taken its toll.”

Then a doctor colleague made an offhand comment, saying, “You shouldn’t be this overweight. There must be something wrong with your gut.” Dr. Hosoda thought about her childhood, riddled with antibiotic use, which is known to weaken the gut. She knew that chronic gut inflammation could manifest into a cluster of symptoms, even presenting like autoimmune diseases.

In fact, a breakthrough Dutch study finds that 80 percent of the body’s immunity is housed in gut bacteria. Wanting to learn more, Dr. Hosoda underwent a Thyroid Peroxidase (TPO) antibody test to see if she had the pro-inflammatory markers that signal an autoimmune thyroid attack. Her score was over 1,000 IU/ml — a healthy reading is below 35. That day, she diagnosed herself with Hashimoto’s thyroiditis, an autoimmune condition where the body’s immune-fighting messaging system is overrun by inflammation and attacks the “master gland” critical for energy, mood, digestion, and weight.

More than 90 percent of women with low thyroid have Hashimoto’s, says Izabella Wentz, PharmD, who wrote Hashimoto’s Protocol: A 90-Day Plan for Reversing Thyroid Symptoms and Getting Your Life Back (Buy from Amazon, $22.28) after curing her own thyroid disease. And Boston University research finds Hashimoto’s is up to 15 times more common in women than men, plus chances of developing it rise with age.

But many women with Hashimoto’s go undiagnosed. Why? The most common thyroid test, Thyroid-Stimulating Hormone (TSH), can be misleading for Hashimoto’s cases, where hormones fluctuate rather than collapse all together. Dr. Wentz says, “It’s absurd: Thyroid antibodies can be elevated for 10 years before a change in TSH is seen.”

The key to healing? Addressing the root cause of the attack: Gut damage. When the gut is inflamed, it can’t absorb thyroid-supporting nutrients. A damaged gut also allows undigested food particles and toxins to spill into the bloodstream (a condition known as “leaky gut”), where they trigger cellular dysfunction and illness.

The best, first step to restoring gut and thyroid function is by following an anti-inflammatory diet. It worked for Dr. Hosoda. She cut back on carbs, eliminated gut-irritating grains, and ate the all-natural foods our hunter/gatherer ancestors were designed to digest best. She learned that when the gut is supported, weight loss is easier. “It’s the difference between pushing a boulder uphill to lose fat, rather than letting it roll downhill and take pounds with it,” she says.

This type of gentle keto/paleo hybrid plan is ideal for women over 50 because it cuts out the dairy that’s difficult for aging bellies to digest, while sidestepping the drastic carb limits that can cause an uptick in stress hormones. Dr. Hosoda says, “Strict keto can impair thyroid function. Women need some carbs to make thyroid hormone.”

Proof of the power of this plan: Researchers found that dieters eating anti-inflammatory foods lost a significant amount of weight. Other research shows that when dieters cut carbs, they may lower their risk of other diseases like diabetes.

As the thyroid heals, the benefits multiply. Dr. Hosoda lost 100 pounds and restored her energy and clarity, plus her thyroid antibodies dropped. Now she helps patients with the same strategies that worked for her.

Ready to slim and heal your tired thyroid? Read on.

So Delicious, So Effective

The best way to stop an autoimmune attack on the thyroid is by following a low-carb anti-inflammatory diet to heal the gut damage that triggers the attack, says Dr. Hosoda. She explains, “In natural medicine, we say, ‘The road to good health is paved with good ‘intestines.’” Dr. Hosoda recommends trying this keto-paleo hybrid plan for six weeks — the time it takes the gut and hormones to begin to rebound.

For starters, you’ll focus on whole foods and dodge processed ingredients. You’ll cut out inflammatory grains and dairy and keep healthy carb intake between 70 and 100 grams of net carbs (total carb grams minus fiber grams) daily. That’s up to four times more carbs than strict keto allows — an approach that prevents further fat-packing hormonal stress, while still guaranteeing slimming. Dr. Hosoda says, “For older women, even those with insulin resistance, this will cause significant weight loss.”

Secondly, you’ll eat cavewoman-style superfoods to heal an inflamed gut and soothe a nutrient-starved thyroid. Top picks: meat, fish, non-starchy veggies, sweet potatoes, berries, hydrating celery and cucumber, and healthy fats like coconut oil. Soak raw nuts in water and cook legumes before eating to remove gut-irritating lectin proteins. And work in the steps that follow to turbocharge results.

Ease stress with selenium. Most women with low thyroid are suffering from a selenium deficiency, which can trigger anxiety. To help, supplement with up to 200 mcg of the mineral, which has been shown to improve thyroid function. Tip: Research finds the best form to take is selenomethionine, which can help with long-term prevention of thyroid problems. One to try: Pure Encapsulations Selenium (Buy from Walmart, $13).

Balance blood sugar. Blood sugar regulation can get out of whack when the thyroid is under attack. To help, snack on collagen-rich bone broth (which soothes the gut lining) mixed with high-fiber, low-calorie shirataki noodles, like Skinny Pasta. “The noodles really help with blood-sugar control on your weight loss journey,” says Dr. Hosoda. Or try her weight-loss supplement: Youthful Slim (Buy from, $59.50 for 90 capsules), which contains blood sugar–controlling berberine and chromium. “It also helps to modulate the immune system,” she says.

The Bread That Speeds Results

Craving a sandwich? Dr. Hosoda tells patients to seek out thyroid-friendly gluten-free breads that won’t create inflammation. Try this recipe with only 2 grams of net carbs, inspired by


  • 4 eggs
  • 2 cups almond flour
  • ⅓ cup warm water
  • ¼ cup melted coconut oil
  • 2 tablespoons ground flaxseed
  • 2 tablespoons psyllium husk
  • 1 tablespoon apple cider vinegar
  • Dash of baking powder
  • Dash of salt


  1. Combine ingredients in large bowl.
  2. Stir and pour into greased pan.
  3. Bake at 350 degrees Fahrenheit, 50 minutes.

Easy Thyroid Self-Exam

This test, created by the American Association of Clinical Endocrinologists, can pinpoint an early sign of hypothyroidism.

  1. Hold a mirror in your hand so you can clearly see your neck.
  2. Take a sip of water and lift your chin.
  3. As you swallow, look above your collarbone, below your Adam’s apple.
  4. If you see any lumps or bulges when swallowing, you may have an enlarged gland. Report your findings to a doctor.

Ask for these 2 thyroid tests.

With health, Dr. Hosoda’s mantra is: “Test, don’t guess!” To get a clearer picture of your thyroid function — beyond the standard TSH test — ask a functional medicine doctor for these screenings:

Thyroid Peroxidase (TPO) antibody test, which measures the level of autoimmune attack on the gland. (Healthy range should be below 35 IU/ml.)

Thyroglobulin (TG) antibody test, which screens for proteins that signal an autoimmune thyroid problem. (Healthy range should be below 35 IU/ml.)

To learn more, find Dr. Hosoda on Instagram and TikTok @doctor.emi, and at her personalized medicine practice, Note: Patients should not stop taking thyroid meds without expert supervision.

Sherri healed her thyroid too.

“I had to go back to basics,” says actress Sherri Shepherd, who improved all her lab results, including her low thyroid, following an anti-inflammatory modified keto plan. She avoided dairy and enjoyed veggies and lean protein. She also dropped 20 pounds. “My doctor was thrilled,” Sherri tells FIRST. “I have so much more energy!”

It Worked For Me: Another Success Story

Standing in the kitchen, Ashley Malik broke into tears. What am I doing wrong? she wondered. She’d been exercising faithfully, yet she was still gaining weight.

Ashley was exhausted. Joint pain made climbing stairs difficult and brain fog meant she forgot names in her tech startup job. She also had mysterious anxiety, heart palpitations, and brittle hair. But after running tests, an endocrinologist said, “You’re fine.”

After three years, Ashley figured her symptoms were menopause and went to a functional medical practitioner. After tests, the doctor shared, “No wonder you’re not feeling well — you have Hashimoto’s.” Lab work also revealed gut inflammation and nutrient deficiencies.

So, Ashley turned to an autoimmune protocol (AIP) diet. She ate anti-inflammatory foods and cut out gluten and dairy. “I love food, so I got excited to see how I could push basic ingredients to make them tasty,” she says. Best of all, she could think clearly again “almost overnight” and started losing weight. Skip ahead: During a checkup, the doctor told Ashley, “You’ve put your Hashimoto’s into remission!” (Her thyroid antibody test fell from 50 IU/ml. to 1.7 IU/ml.) “What I’ve lost in physical weight, I’ve gained in mental joy,” says Ashley, who is now a health coach. “I want women to know weight loss is possible—even with thyroid issues!”

Smiling blonde woman
Ashley Malik, 47, Centennial, CO, lost 55 lbs

This article originally appeared in our print magazine, First For Women.

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