Does Your Thyroid Really Control Your Weight Loss?

When it comes to weight loss, we preach the importance of diet and exercise, but the truth is there is a lot that goes on in our bodies that regulates our ability to gain and lose weight! The most influential part of our endocrine system is our thyroid, which is a gland in the back of our neck that regulates the production and distribution of two hormones: thyroxine (T-4) and triiodothyronine (T-3). These two hormones regulate the metabolism of our cells.

thyroid exam

Research has revealed that there is a deep-rooted connection between thyroid conditions, bodyweight and metabolism. Since the thyroid controls the metabolism, it heavily impacts our weight. We measure the activity of our metabolism by determining the amount of oxygen our body uses over a specific amount of time. One of the most well known ways of conducting this measurement is by calculating our basal metabolic rate, or BMR. An individual’s BMR is measured by calculating total oxygen usage while the body is at rest. Experts have discovered a correlation between malfunctioning thyroid glands and BMRs. When a thyroid gland is working too slowly, the patient tends to have a lower BMR. When a thyroid gland is over productive, a condition known as hyperthyroidism, the BMR tends to be much higher.

>> Read more: Overactive vs. Underactive Thyroid: What's the Difference?

What is hyperthyroidism? Hyperthyroidism is an illness where the thyroid is overactive. It releases excess hormones into our bloodstream, which forces the metabolism to work faster than necessary. This often results in weight loss. The amount of weight an individual loses is directly related to how overactive the thyroid is. Depending on how severe the condition is, an individual will need to increase the amount of calories they consume in order to maintain their weight. If there is a deficiency in caloric intake, the individual may lose weight at a dangerous rate, which could lead to a variety of other health problems. However, weight loss is not always a primary symptom of hyperthyroidism. This condition sends the metabolism into overdrive, which increases the appetite. Depending on how much you eat – and what kinds of food you eat – you may actually gain weight.

What are the symptoms? While this condition is often challenging to diagnose, there are several symptoms that may stand out. These could include:

  • Sudden weight loss
  • Tachycardia (rapid heartbeat)
  • Increased appetite
  • Nervousness, anxiety, and irritability
  • Increased sensitivity to heat
  • Change in menstrual patterns
  • Enlarged thyroid gland
  • Fine, brittle hair

Check out the full list at Mayo Clinic.

thyroid gland


What are the causes? Thyroid issues are often hereditary, but there are several conditions that often lead to hyperthyroidism:

  • Graves’ disease: An autoimmune disease where your immune system stimulates your thyroid to produce too much T-4 (one of the hormones that that the thyroid produces).
  • Hyperfunctioning thyroid nodules: These include conditions like toxic adenoma, toxic multinodular goiter, and Plummer’s disease. These occur when one or more adenomas (a part of the gland that has separated from the rest of the thyroid) produce too much T-4.
  • Thyroiditis: An inflammation that causes excess thyroid hormones to leak into the bloodstream. This condition can sometimes occur after pregnancy.

What are the treatments? Luckily, hyperthyroidism is a common condition, and there are many options when it comes to treatments. Here are some of the most popular choices:

  • Radioactive iodine: An oral medication that causes the thyroid to shrink. It can take 3-6 months to become fully effective.
  • Anti-thyroid medications: These medications prevent the thyroid gland from generating extra amounts of hormones. It usually takes about 6-12 weeks to relieve symptoms.
  • Beta blockers: These help reduce tachycardia and heart palpitations, which are common symptoms of hyperthyroidism.
  • Surgery: A thyroidectomy, or the removal of most of the thyroid gland, is rarely used, as it requires lifelong treatment in order to maintain normal hormone balance throughout the body.

Hyperthyroidism is a very common condition, especially in women, and it is estimated that 1 in 20 people suffer from some kind of thyroid issue. Talk to your doctor if you have any questions, or check out our sources here: American Thyroid AssociationEmpowerMayo Clinic, and the British Thyroid Foundation.