What Should I Eat If My Thyroid Is Low? A Comprehensive Diet Guide

October 30, 2025 •

4 min read

According to the American Thyroid Association, an estimated 20 million Americans have some form of thyroid disease, with hypothyroidism being one of the most common. For those with an underactive thyroid, dietary choices can play a key role in managing symptoms and supporting overall health alongside medical treatment.

Quick Summary

Optimizing your diet with specific nutrients like iodine, selenium, and zinc can support thyroid function and mitigate hypothyroidism symptoms such as fatigue and weight gain. Medical treatment remains crucial.

Key Points

Prioritize Key Nutrients: Focus on foods rich in iodine (seafood, dairy), selenium (Brazil nuts, eggs), and zinc (shellfish, pumpkin seeds) to support thyroid hormone production and function.
Mindful of Goitrogens: Enjoy cruciferous vegetables like broccoli and kale, but consume them cooked rather than raw, as cooking deactivates their goitrogenic compounds.
Time Medication and Food: Separate your thyroid medication from meals, especially those containing soy, excessive fiber, or high calcium, by several hours to ensure optimal absorption.
Limit Processed Foods: Reduce intake of processed foods, refined sugars, and inflammatory fats, which can exacerbate symptoms of hypothyroidism.
Consider Gluten Sensitivity: For those with Hashimoto's, there can be a link to gluten sensitivity, but consult a doctor before eliminating it completely.
Seek Professional Guidance: Always work with a healthcare provider or registered dietitian to tailor a diet plan that meets your individual needs and complements your medical treatment.

The Role of Diet in Managing an Underactive Thyroid

While medication is the primary treatment for an underactive thyroid (hypothyroidism), diet provides essential nutrients that support thyroid function and help manage symptoms. Your thyroid gland relies on specific vitamins and minerals to produce hormones that regulate your metabolism, energy, and body temperature. A balanced diet focusing on whole, unprocessed foods is key to providing these necessary building blocks and reducing inflammation that can exacerbate thyroid conditions.

Key Nutrients for a Low Thyroid

Several nutrients are particularly important for thyroid health. Incorporating foods rich in these vitamins and minerals can make a significant difference.

Iodine: Essential for Hormone Production

Iodine is a trace mineral that is a crucial component of thyroid hormones. The body cannot produce iodine, so it must be obtained from food.

Iodized salt: Most table salt in the U.S. is fortified with iodine.
Seaweed: Kelp, nori, and dulse are excellent sources, but should be consumed in moderation due to very high iodine levels.
Fish and shellfish: Cod, tuna, and shrimp are good options.
Dairy products: Milk, yogurt, and cheese contain iodine.
Eggs: A complete nutritional package that includes both iodine and selenium.

Selenium: The Converter Nutrient

Selenium is a trace mineral that helps activate thyroid hormones, enabling them to be used by the body. It also has antioxidant properties that protect the thyroid gland from oxidative stress.

Brazil nuts: A small handful can provide more than the daily recommended amount of selenium.
Fish: Tuna, salmon, and sardines are rich sources.
Eggs: The yolk, in particular, is concentrated with selenium.
Legumes: Lentils and beans also contain selenium.

Zinc: Crucial for Hormone Synthesis

Zinc is an essential mineral involved in the production of thyroid hormones and the regulation of TSH (thyroid-stimulating hormone).

Shellfish: Oysters are one of the best sources.
Beef and poultry: Excellent sources of dietary zinc.
Pumpkin seeds: A plant-based option rich in zinc.
Legumes: Beans, lentils, and chickpeas are good sources.

Other Important Nutrients

Iron: Iron deficiency can impair thyroid function. Sources include lean meats, fish, spinach, and fortified cereals.
B Vitamins: Vitamins B2, B3, B6, and B12 are important for hormone production and energy levels. Found in fish, dairy, eggs, and legumes.
Omega-3 Fatty Acids: These can help reduce inflammation. Look for fatty fish like salmon and sardines, as well as flaxseeds and walnuts.
Antioxidants: Found in berries, leafy greens, and spices like turmeric, antioxidants protect against cellular damage.

Foods and Substances to Limit or Avoid

Certain foods can interfere with thyroid hormone production or absorption, especially if consumed in large quantities or at specific times.

Goitrogenic Foods: The Raw vs. Cooked Debate

Goitrogens are substances in some plant foods that can interfere with thyroid function by affecting iodine uptake. Cruciferous vegetables contain goitrogens, but their impact is often exaggerated. Cooking significantly reduces their goitrogenic effect, so moderate amounts of cooked cruciferous vegetables are generally safe and nutritious.

Cruciferous vegetables: Broccoli, cauliflower, cabbage, kale, and Brussels sprouts. Enjoy them steamed or roasted.
Peaches and strawberries: Contain goitrogenic compounds but are fine in moderation.
Millet: Some evidence suggests it may affect thyroid function.

Soy Products

Soy contains isoflavones that can interfere with the absorption of synthetic thyroid hormone (levothyroxine). It is best to wait at least four hours after taking your medication before consuming soy milk, tofu, or other soy products.

Processed Foods and Sugar

Highly processed foods and those high in added sugars can increase inflammation and contribute to weight gain, which is a common symptom of hypothyroidism.

Gluten and Autoimmune Thyroid Disease

Some people with autoimmune thyroid disease, like Hashimoto's, may also have celiac disease or a gluten sensitivity. In these cases, a gluten-free diet may help reduce symptoms. However, it is not a universally recommended diet for all hypothyroid patients. Always consult a healthcare professional before eliminating gluten.

Comparing Thyroid-Friendly and Potentially Problematic Foods


Foods to Favor	Foods to Limit/Manage	Explanation
Fatty Fish (Salmon, Tuna)	Raw Cruciferous Veggies (Broccoli, Kale)	Provides Omega-3s and selenium; raw goitrogens can interfere with thyroid function, but cooking deactivates them.
Eggs and Dairy	Soy Products (Tofu, Soy Milk)	Excellent sources of iodine and selenium; soy can block medication absorption, so time your intake carefully.
Brazil Nuts	Processed Foods and Sugar	Extremely rich in selenium; these foods can increase inflammation and weight gain.
Pumpkin Seeds	Excessive Fiber Intake	Rich in zinc; while fiber is good, too much can interfere with medication absorption. Space intake by 4 hours.
Lean Meats	Excessive Iodine	Good source of iron and protein; too much can be as problematic as too little. Balance is key.
Fruits and Berries	Grapefruit Juice	Rich in antioxidants and fiber; can interfere with the absorption of thyroid medication.

Practical Dietary Tips

Meal Timing: Take your thyroid medication (e.g., levothyroxine) on an empty stomach, at least 30-60 minutes before breakfast, to ensure proper absorption.
Read Labels: Be mindful of hidden ingredients, especially soy, in processed foods.
Portion Control: Hypothyroidism can slow metabolism, making weight management challenging. Consistent meal times and portion control can help.
Adequate Hydration: Drinking plenty of water is beneficial for metabolism and overall health.
Cook Vegetables: Cooking goitrogenic vegetables significantly reduces their impact on the thyroid, so you can still enjoy their nutritional benefits.
Balance Fiber and Meds: High-fiber foods can affect medication absorption. If you have a high-fiber diet, discuss the timing of your medication with your doctor.

Conclusion

While an underactive thyroid requires medical management, adopting a nutrient-rich diet can be a powerful tool for supporting thyroid function and mitigating symptoms. By focusing on key nutrients like iodine, selenium, and zinc found in whole foods and being mindful of substances that can interfere with medication, you can positively impact your overall health. Remember that dietary needs can be highly individual, and working with a healthcare professional is the best way to develop a personalized plan. For more information on managing thyroid conditions, you can visit a trusted resource such as Healthline.

Frequently Asked Questions

A balanced breakfast that includes protein and healthy fats, such as scrambled eggs with spinach and a side of fruit, is an excellent choice. The eggs provide iodine and selenium, while spinach offers iron and antioxidants.

Yes, but it's important to time it correctly. Coffee can interfere with the absorption of thyroid medication, so you should wait at least 30-60 minutes after taking your medication before drinking it.

Using iodized table salt is a common way to ensure adequate intake. Including moderate portions of fish, dairy, and eggs is also helpful. Avoid excessive consumption of high-iodine foods like kelp, and consult your doctor before taking iodine supplements.

No, cooking cruciferous vegetables like broccoli and cauliflower significantly reduces their goitrogenic effect. Eating them in moderation as part of a varied diet is perfectly healthy.

Selenium helps the body convert the inactive thyroid hormone (T4) into its active form (T3). It also acts as an antioxidant, protecting the thyroid gland from damage.

Soy contains isoflavones that can block the absorption of synthetic thyroid hormone medication (levothyroxine), reducing its effectiveness. It is best to wait several hours between taking your medication and consuming soy products.

Fatty fish like salmon and tuna are excellent choices, as they are rich in omega-3 fatty acids, iodine, and selenium, which all support thyroid and overall health.

Untreated hypothyroidism can cause weight gain due to a slowed metabolism. However, a balanced diet, regular exercise, and proper medical treatment can help manage and reverse this symptom effectively.