Derek Burnett
Derek Burnett is a Contributing Writer at Bottom Line Personal, where he writes frequently on health and wellness. He is also a contributing editor with Reader’s Digest magazine.
Losing weight is difficult enough to begin with, but when you add in an underactive thyroid (hypothyroidism), the challenge becomes that much greater. Still, it’s possible to lose weight despite having hypothyroidism. But it helps to know a bit about the condition and how to work around it.
On the front of your neck, right around the area of your voice box, nestles a butterfly-shaped gland, roughly two inches long, called the thyroid. As part of the endocrine system, like many other glands, the thyroid secretes hormones. Among other functions, the hormones produced by the thyroid affect your metabolism—the rate at which your body consumes energy. An increase or decrease in thyroid hormone can have serious effects on both the body and mind, raising or lowering energy levels, affecting thinking and mood, speeding or slowing heart rate and breathing, raising and lowering body temperature, and speeding or slowing the movement of food through your digestive tract.
The two main metabolism-related hormones secreted by the thyroid are thyroxine (known as T4) and triiodothyronine (T3). The thyroid produces considerably more T4 than T3, but T4 has little effect until it converts naturally to T3. The amounts of these hormones secreted by the thyroid are regulated by the pituitary, the tiny “master gland” located beneath the brain, which releases hormones of its own to communicate with the thyroid about how much hormone to secrete.
For various reasons, a person’s thyroid may produce too much hormone (hyperthyroidism) or too little (hypothyroidism). When the thyroid produces insufficient hormone, metabolism slows and patients normally begin to put on weight because their bodies are not burning calories at an acceptable rate. In addition, patients often experience constipation, low energy levels, loss of appetite, brain fog, muscle stiffness, a slowed heart rate, fatigue, depression, and an inability to tolerate cold temperatures. About 10 million Americans suffer from hypothyroidism.
Sometimes hypothyroidism occurs with no discernible cause. Other times, it happens as a side effect to medication, as a symptom of an immune disorder, because of exposure to certain chemicals known as endocrine disruptors, or due to a deficiency of iodine. The most common cause in the US and other developed countries where access to iodine is not a problem is the autoimmune disorder known as Hashimoto’s disease. Hashimoto’s affects 5% of Americans, the vast majority of them women, who are up to 10 times more likely to have the condition than men. Symptoms of Hashimoto’s include fatigue, lethargy, feeling cold, and sleeping more than usual.
Hypothyroidism slows the rate at which food passes through your system, meaning that your body has longer to absorb nutrition from it. A low thyroid slows metabolism by up to 50%. It can therefore be extremely difficult to maintain a caloric deficit and shed pounds with hypothyroidism.
There is no specific “hypothyroidism diet.” To lose weight with an underactive thyroid, you should eat the same kinds of healthy foods as anyone looking to lose weight or boost their overall health, including a rainbow of fruits and vegetables, such as leafy greens and legumes, as well as nuts. The Mediterranean diet is an eating pattern proven to be associated with positive health outcomes and is a great way for anyone to lose weight. It reduces the amount of ultraprocessed foods a person eats, and emphasizes vegetables and fruits, fish, nuts, and olive oil. It avoids animal fats, sugars, and excess salt.
Speaking of salt, the thyroid requires iodine to produce its hormones, and the primary source of iodine for most Westerners is iodized salt. It’s important for people with hypothyroidism to get enough iodine, but you don’t need to consume it in copious amounts. In fact, too much iodine can exacerbate hypothyroidism. Salt isn’t the only source of iodine, however. It’s also contained in fish, shellfish, cheese, yogurt, and seaweed.
Selenium and zinc may also support the production of your thyroid hormone. Nuts and seeds are excellent sources of both of these minerals, and both of them are plentiful in the Mediterranean diet and other dietary plans that emphasize plant-based foods.
You may wish to be cautious with foods containing soy. Some research has connected high consumption of soy foods with thyroid problems, but that evidence is outweighed by many other studies showing no such association. However, if you’ve been prescribed levothyroxine (Synthroid) for an underactive thyroid, avoid soy proteins, since they interfere with absorption of the drug.
Exercise is often difficult for people with hypothyroidism, since they may experience low energy, fatigue, and joint pain. However, there is research to suggest that exercise improves thyroid function. Seek out low-impact exercises that are easy on the joints, such as tai chi, yoga, walking, and water aerobics. Aim for about 2.5 hours or more of moderate-intensity exercise each week.
However, no amount of eating healthy foods and exercising will help you lose weight as much as addressing your thyroid problem. If you have any suspicion that you may have an underactive thyroid, get tested and begin the process of taking care of it so that you can get on with your weight loss.
The approach to treating hypothyroidism will depend upon what’s causing it. Your doctor will begin by testing your hormone levels to confirm a diagnosis, but will also determine whether your hypothyroidism is primary (meaning that the problem lies with the thyroid itself) or secondary (meaning the problem is with the pituitary gland). Most approaches will consist of trying to treat the underlying cause. In many cases, doctors prescribe synthetic thyroid hormones as a substitute for those the thyroid is failing to produce.
