Graves' Disease and Weight Loss: What You Need To Know

What is Graves’ disease?

Graves' disease is an autoimmune disorder where the immune system produces antibodies that stimulate the thyroid gland. This results in an overactive thyroid gland and excess production of the T3 or T4 thyroid hormones.

Graves’ disease is the leading cause of hyperthyroidism, making up 60 to 80%¹ of cases. You are also 5 to 10 times² more likely to develop the condition if you are female.³ 

Known risk factors for Graves’ disease include high stress levels and smoking, as well as your gender, family medical history, and having an existing autoimmune disease. 

There are many signs and symptoms of Graves’ disease, one of the most common being weight loss.⁴ While this can be treated, there is often a significant risk of excessive weight gain,⁴ which can instead cause the thyroid to become underactive. 

When is weight loss a concern with Graves’ disease?

Unexplained weight loss often occurs in people who have Graves’ disease. Although weight loss may not always appear to be a concern, it can be dangerous and lead to serious problems, such as malnutrition, if left untreated.

Early treatment of Graves’ disease is vital to prevent damage to organs and other body parts, which can sometimes be fatal. 

Why does Graves’ disease cause weight loss?

The thyroid uses iodine to make thyroid hormones (T3 and T4) which regulate how the body utilizes energy. If you have Graves’ disease, many of your bodily processes are accelerated due to overstimulation of the thyroid. This causes an increase in your basal metabolism, where the body burns more energy while at rest. 

Although people with Graves’ disease often report having a larger appetite, the additional food consumption is still not enough to compensate for the increased energy expenditure that causes weight loss.

The body continues to break down fuel at a rate faster than it can replenish it. The body will essentially begin to consume itself, using bone and muscle as a source of energy. 

Diagnosis

If it is suspected that you may have Graves’ disease, you will initially be tested for hyperthyroidism. This involves a blood test to see if you have suppressed levels of TSH. 

Accurate diagnosis is important for assessing whether you have Graves’ disease, so your doctor will likely also test for elevated levels of T3 or T4 thyroid hormones. Specific antibody markers in the blood, TSH-R-Ab, are used to confirm whether you have Graves’ disease.

Treatment

If you have Graves’ disease, there are a number of effective treatments available to prevent the associated weight loss. These treatments aim to reduce thyroid hormone synthesis and restore normal thyroid hormone levels. 

Correcting the thyroid hormone balance should normalize your metabolism and halt your weight loss. 

Common treatments options include: 

Antithyroid medication

These medications stop thyroid hormone production and the symptoms of an overactive thyroid gland. However, as these medications do not treat the actual disease, relapse is common. 

Radioactive iodine treatment (RAI)

Radioactive iodine treatment (RAI) gives you a powerful dose of radioactive iodine to eliminate cells in the thyroid gland and decrease hormone production. While this is considered an effective treatment to cure Graves’ disease, it often results in more serious side effects and radiation risk. 

For example, one study⁴ showed that RAI treatment contributed to weight gain and hypothyroidism, compared with antithyroid medication, which did not produce such side effects.

Thyroidectomy

A thyroidectomy involves the surgical removal of the thyroid gland. Although this treatment effectively eliminates hyperthyroidism, it is the least common option in this list due to the surgical risk and likelihood of developing hypothyroidism as a result. 

To determine the right treatment option for your situation, you should discuss the advantages and disadvantages of each treatment with your doctor.

There are risks to be aware of with each treatment. A common side effect is hypothyroidism, where you have an underactive thyroid and inadequate thyroid levels. Hypothyroidism requires long-term hormone replacement therapy to balance thyroid hormone levels.

Another risk of treatment is that it can involve overshooting the target weight gain goal, leading to obesity. To prevent or manage any unwanted weight gain, you should discuss what proactive measures you can take with your doctor.

Managing weight loss

Diet

While diet alone is unlikely to treat or prevent Graves’ disease, it can improve symptoms and reduce weight loss. 

Increasing your calorie consumption can help you gain weight and minimize muscle wasting associated with the disease. Incorporating vitamins and minerals such as calcium and vitamin D may also help prevent osteoporosis due to bone loss. 

Other foods that may alleviate symptoms of Graves’ disease include cruciferous vegetables,⁵ which have been shown to reduce iodine uptake, and foods rich in iron and/or selenium.

However, precaution should be taken to avoid or limit iodine-rich foods,⁶ such as kelp, seaweed, seafood, and iodine supplements, as high iodine levels can exacerbate weight loss. 

Conversely, since some treatments have been shown to cause weight gain, if you are concerned about gaining too much weight, it may be suitable to eat a lower calorie diet that is still high in essential nutrients. 

Exercise

Although exercise is an important factor in maintaining general health, caution must be taken if you have Graves’ disease not to overexert yourself. This can cause your body to become severely overheated, causing damage to your heart since hyperthyroidism is linked to an already increased resting heart rate. 

Exercise could also accelerate weight loss, muscle breakdown, and bone loss associated with an overactive thyroid. 

However, research⁷ has shown that small amounts of weight-bearing exercise can help to reduce bone loss and increase muscle mass. Gentle exercise, such as yoga and tai chi, may also positively affect thyroid hormone levels to reduce weight loss. 

The lowdown

Graves’ disease is a serious health concern that requires early detection and treatment. One of the major complications resulting from the disease is considerable weight loss due to increased levels of thyroid hormone and an increased metabolic rate. 

If you have Graves’ disease, it is essential that you seek advice and individualized treatment from your healthcare provider.