How To Safely Lose Weight With Hyperthyroidism

It's no secret that thyroid disorders can have an impact on your weight. While hyperthyroidism, in particular, is known for causing individuals to lose weight, it can also be connected to weight gain after your thyroid levels have been normalized. The good news is that losing weight with hyperthyroidism is possible.

Here's what you should know about losing weight while managing the symptoms of an overactive thyroid. 

What does your thyroid gland do?

Your thyroid is a small gland shaped like a butterfly and located in the front of your neck. It produces T3 and T4 hormones responsible for helping other body parts work as they should, including your heart and metabolism.

When your thyroid produces too many hormones, it's called hyperthyroidism and causes other systems in your body to speed up. When your thyroid doesn't produce enough hormones, it's called hypothyroidism and causes other systems in your body to slow down.

What are the symptoms of hyperthyroidism?

Hyperthyroidism is most commonly caused by Graves' disease, which causes your immune system to attack your thyroid gland as if it were an invader. It is also most likely to occur in women who have a family history of autoimmune diseases or thyroid disease. Hyperthyroidism can cause many symptoms that vary from person to person. Some signs of an overactive thyroid include:

• Weight loss with an increased appetite

• Nervousness or irritability

• Racing heart

• Shaky hands

• Difficulty sleeping

• Sweating

• Menstrual cycle changes

• More frequent bowel movements

• Muscle weakness

• Fine, brittle, thinning hair

What is the relationship between thyroid function and weight?

As with other bodily functions, the thyroid hormone helps manage your metabolism. According to the American Thyroid Association, your metabolism is determined by measuring how much oxygen your body uses in a specific amount of time. When this is measured while you're resting, it's called the basal metabolic rate (BMR). Generally speaking, patients with low thyroid function have low BMRs, while patients with overactive thyroids have high BMRs.

While there is undoubtedly a connection between thyroid function, metabolism, and weight, this relationship is very complex and is affected by other factors and chemicals. Because of this, it's impossible to predict the effect changing your thyroid hormone level would have on your weight.

Does hyperthyroidism typically cause weight gain?

It's common for people with untreated hyperthyroidism to experience unintentional weight loss as their metabolism tends to speed up due to the overproduction of T3 and T4 hormones.

However, once your symptoms of an overactive thyroid have been treated with anti-thyroid medications and your thyroid function has been regulated, you may experience weight gain,¹ sometimes to the point of being obese.

The following mechanisms can cause excessive weight gain:

• A lower than normal energy expenditure without a corresponding reduction in food intake or appetite

• Inadequate thyroid hormone replacement

Why might you gain weight even if your hyperthyroidism is treated?

When a person develops hyperthyroidism, they often experience symptoms like weight loss and an increased appetite. Because of this, they can consume more calories than they otherwise would without gaining any weight.

After their hyperthyroidism is treated, it's normal for them to gain weight as their metabolism slows down. However, if the person doesn't make any changes in their diet, they can expect to not only return to their normal weight prior to developing an overactive thyroid but also gain more weight.

How to safely lose weight with hyperthyroidism

If you're being treated for an overactive thyroid and are striving to lose weight, there are steps you can take to manage your weight without jeopardizing your health, including:

Eating a well-balanced diet

Consuming a variety of foods high in protein, rich in nutrients, and low in fat can help you maintain a healthy weight. Additionally, it's important to monitor your portion sizes and only eat until you're satisfied.

Exercising regularly

Incorporating physical activity into your regular routine can help keep excess weight off. Staying active doesn't have to be difficult. It can be as simple as going for daily walks, riding your bike around the neighborhood, or swimming a few times a week.

Monitoring your thyroid levels

Having your thyroid levels checked every three months in the first eighteen months can ensure that your thyroid function stays within normal range, preventing unexpected weight fluctuations.

Taking your medication regularly

Even if you're gaining weight, taking your anti-thyroid medication as prescribed is critical. A sudden stop to your medication could lead to complications worse than seeing an increase in your weight.

When to speak to a healthcare professional

If you have been diagnosed with an overactive thyroid and are concerned about gaining weight or have experienced an increase in your weight since regulating your thyroid hormone levels, it's best to schedule an appointment with your primary care doctor or endocrinologist.

Along with checking if your thyroid hormone levels are within a normal range, your doctor can guide you on effective, safe ways to lose weight or maintain your goal weight. 

The lowdown

When your thyroid isn't working properly, it can affect other systems of your body, including your metabolism and weight.

In the case of an overactive thyroid, many people lose weight without trying until their hyperthyroidism is treated.

After treatment, however, it's common for people with hyperthyroidism to gain the weight back, sometimes to the point of being overweight or obese.

When this occurs, losing weight is possible by eating a healthy diet, staying active, taking your anti-thyroid medication continuously as directed, and working closely with your doctor to monitor your thyroid hormone levels.