Thyroid hormones play an essential role in regulating metabolism, a process that affects weight. The thyroid gland, located in the neck, produces hormones that control the body’s metabolism, or the rate at which the body burns calories for energy.

Various thyroid conditions can affect an individual’s weight, sometimes causing obesity.

What is Thyroid Hormone?

Thyroid hormone is a chemical produced by the thyroid gland that regulates the body’s metabolism.

This hormone controls the rate of the body’s energy use, how quickly food is broken down and used, and its impact on other hormones within the body. The thyroid gland contains two types of hormones: thyroxine (T4) and triiodothyronine (T3).

T4 is the primary hormone produced and is converted by the body to T3, the active hormone. T3 plays a critical role in regulating metabolism, whereas T4 is more important as a reserve hormone that can be converted into active T3 as needed.

Abnormal levels of T4 and T3 in the bloodstream can cause a wide range of health problems, including obesity.

Hyperthyroidism and Obesity

Hyperthyroidism is the medical term for an overactive thyroid gland that produces an excess of thyroid hormone.

Individuals with hyperthyroidism often experience unexplained weight loss due to the increase in metabolism that causes the body to burn calories at a faster rate.

However, some individuals with hyperthyroidism experience weight gain due to an increase in appetite and food intake. This is because the excess thyroid hormone can signal the brain to stimulate hunger.

These individuals may also have increased fluid retention, which can cause additional weight gain.

Hypothyroidism and Obesity

Hypothyroidism is the medical term for an underactive thyroid gland that produces an insufficient amount of thyroid hormone. Individuals with hypothyroidism may experience weight gain or difficulty losing weight due to a decrease in metabolism.

When the body does not receive enough thyroid hormone, it slows down its metabolic processes, including how quickly it burns calories for energy. This slowdown can result in weight gain, even if an individual is not eating more food.

Thyroid Cancer and Obesity

Thyroid cancer can cause obesity due to various factors. Treatment for thyroid cancer typically involves removing part or all of the thyroid gland, which can disrupt the body’s metabolism and result in weight gain.

Additionally, the medications used to treat thyroid cancer can cause weight gain as a side effect.

Thyroid Hormone Replacement Therapy and Weight Loss

Individuals with hypothyroidism can take thyroid hormone replacement therapy to restore the thyroid hormone levels in their body to a normal range.

This treatment can help improve symptoms of hypothyroidism, such as fatigue, weight gain, and difficulty losing weight.

Some individuals may experience weight loss as a side effect of thyroid hormone replacement therapy, especially if their hypothyroidism was causing significant weight gain.

However, many individuals will not experience weight loss with this treatment, and some may even experience weight gain due to the increase in their metabolism.

Conclusion

The thyroid gland plays a vital role in regulating metabolism, a process that affects weight. Various thyroid conditions, including hyperthyroidism, hypothyroidism, and thyroid cancer, can cause obesity or affect an individual’s weight.

If you are experiencing unexplained weight gain or loss, it is essential to speak with your doctor to determine if an underlying thyroid condition is the cause.