The thyroid is a gland that produces hormones important for energy levels, mood and metabolism. If your thyroid produces too few hormones, you have a condition known as hypothyroidism. Depending on the severity of your condition, your doctor may prescribe synthetic thyroid medications. A healthy diet, limited in certain foods, may help minimize your symptoms, which may include lethargy, depression, constipation, weight gain, menstrual irregularities and sensitivity to cold. For best results, seek guidance from your doctor or dietitian.
Enriched flour derives from a whole grain. Processing strips the grains of valuable vitamins, minerals, fiber and protein content. As a result, enriched flour products have a high glycemic index, meaning they impact your blood sugar levels. The University Medical Center recommends eating whole grains to help reduce symptoms of hypothyroidism. For best results, replace enriched white and wheat breads, cereals, pasta and snack foods in your diet with complex carbohydrates, such as whole grains.
Added sugars, such as cane sugar, brown sugar, corn syrup, rice syrup, dextrose, fructose and maltose, add calories and sweetness but few nutritional benefits to foods. Like enriched flour products, added sugars can disrupt your blood sugar, moods and energy levels and make it more difficult to manage your appetite and weight. Consuming excessive amounts of sugary foods or beverages also leaves less room in your diet for the naturally sweet foods recommended for hypothyroidism patients, such as blueberries and cherries. To reduce your added sugar intake, replace table sugar and honey in your tea or coffee with stevia -- a calorie-free, sweet-tasting herb that provides antioxidant benefits. Foods and beverages particularly high in added sugars include candy, milk chocolate, pancake syrup, jelly, frozen desserts, frosting, pastries, regular soft drinks and fruit punch.
Some vegetables, though valuable sources of antioxidants and fiber, may interfere with thyroid function and thyroid medications. For this reason, the University of Maryland Medical Center recommends avoiding spinach, kale, mustard greens, cabbage, cauliflower, Brussels sprouts, broccoli and turnips if you have underactive thyroid. Since skinless potatoes have a high glycemic index rating and may offset blood sugar and hormonal levels. Avoid mashed potatoes and skinless baked potatoes. Fried vegetables, such as french fries, onions rings and fried okra, may increase inflammation and add to thyroid-related weight gain. Choose fresh, thyroid-friendly varieties instead.
Gluten is a storage protein in wheat, barley and rye. A correlation stands between gluten intolerance and thyroid disease, according to a "Today's Dietitian" article published in November 2010. Gluten intolerance can be difficult to recognize if you have hypothyroidism, since numerous symptoms, including bloating, abdominal pain and digestive problems, tend to overlap and make it difficult to recognize. If you sense that gluten-containing foods, such as wheat and white breads, most cold cereals, crackers and commercially prepared baked goods, trigger or worsen your thyroid symptoms, try opting for gluten-free whole grains, such as brown rice, wild rice and popcorn, instead. Other less obvious sources of gluten include soy sauce, meat marinades, some oatmeal varieties, seitan -- a vegetarian protein source -- tabouleh, couscous and Worcestershire sauce.
Protein foods that interfere with thyroid function include peanuts, pine nuts, soybeans and grains, such as millet and cassava, and linseed, also called flaxseed. If you take thyroid hormones, the University of Maryland Medical Center suggests speaking with your doctor before using soy products, because they may interfere with the absorption of your medication.