Thyroid problems can cause several seemingly unrelated issues throughout the body.  

These include changes to your weight, energy, digestion, and mood. These are all linked to the thyroid because it directs important processes that happen throughout the body and makes losing weight with hypothyroidism so very difficult.  Thyroid hormones help control your metabolism. When the levels are too low, metabolism slows down. Symptoms can include feeling chilly, fatigued, getting constipated, feeling down, and gaining weight. Low levels of thyroid hormone is called hypothyroidism. There are some important foods and nutrients that can help you feel better and manage your weight. By providing your body with proper nutrition—along with prescribed medications—you can help reduce your symptoms and lose weight.

Before we dive into my nutrition tips for you, let’s start by understanding the thyroid and why it’s so important for your body and mind.

What Does Your Thyroid Do?

Your thyroid is a butterfly-shaped gland at the front of your neck that secretes hormones. These hormones affect many processes throughout the body, including your breathing, heart rate, body temperature, and brain, and are well known for their influence on your metabolism.

When thyroid hormones are high, many systems speed up. When hormone levels are low, they slow down. Thyroid hormones are very important during pregnancy and breastfeeding. Not only for the health of the mother but also the developing baby.

Hormones produced by the thyroid helpwith proper development of babies’ bones, brains, and nervous systems.



Hypothyroidism is when your thyroid gland is not producing enough hormones. Hypothyroidism affects nearly 1 in 20 Americans over the age of 12. On the other hand, overactive thyroids, also known as hyperthyroidism, is less common and affects as few as 1 in 100 Americans. Thyroid problems occur most often in women, people over 60 years old, and those with a family history of thyroid issues.

Because of the role thyroid hormones play in regulating your metabolism, people with hypothyroidism often find it difficult to lose weight. 

Causes of Hypothyroidism

The most common cause of hypothyroidism is an autoimmune condition called, Hashimoto’s Disease. Hashimoto’s disease occurs when your body’s immune system mistakenly attacks and destroys your body’s cells. People with other autoimmune conditions, such as celiac disease or type 1 diabetes, are more likely to develop Hashimoto’s disease than others. 

Hashimoto’s disease is not the only cause of hyperthyroidism. Some other causes include, 

    • Inflammation
    • Iodine deficiency
    • Other coniditions
    • Medications

Symptoms of Hypothyroidism

There are many symptoms of hypothyroidism. Some common ones include:

    • Fatigue and weakness 
    • Weight gain 
    • Trouble tolerating the cold 
    • Difficult concentration and memory problems 
    • Joint and muscle pain 
    • Constipation
    • Dry or thinning skin, hair and nails
    • Heavy or irregular menstrual problems 
    • Fertility problems 
    • Slow heart rate 

Symptoms of hypothyroidism can vary from person to person, so your symptoms may not align with someone else’s. Hypothyroidism develops gradually over time, so many people don’t notice symptoms for months or even years. 

Testing and Treatment of Hypothyroidism

Some symptoms of hypothyroidism weight change or fatigue—can be subtle.

Your doctor can order blood test to determine your thyroid hormones levels, and confirm hypothyroidism. If you are experiencing signs and symptoms of hypothyroidism, it’s important to chat with your doctor as hypothyroidism can increase your risk of high cholesterol, high blood pressure and heart disease. 

The good news is that an under-active thyroid can be treated! Your doctor can prescribe you medications to replace the hormones that your thyroid is no longer making. Your doctor can work with you to find the right dose to improve your symptoms.

Thyroid and Weight

The thyroid helps to control metabolism, so it can directly impact your weight. With hypothyroidism, the body isn’t metabolizing (using energy) as well as it could be. This means that more of the foods and drinks we consume aren’t used as effectively by the body. This can lead you to wonder how to lose weight with hypothyroidism. Weight gain is just one of many symptoms of hypothyroidism. Many things can cause weight gain, and therefore, it may not result from hypothyroidism. In fact, if weight gain is the only symptom of hypothyroidism, it’s less likely to be from hypothyroidism. Other factors that can affect your metabolism (and weight) are other hormones, food intake, and your own body weight. In general, weight gain associated with hypothyroidism is about 5-10 pounds. This means that when hypothyroidism is diagnosed and treated, weight loss is fairly small. Typically, successful treatment of hypothyroidism results in a return to the body weight before the hypothyroidism developed.


Iodine is one of the key minerals that your thyroid needs to make hormones. Without sufficient amounts of iodine, your thyroid will not be able to make enough hormones. Health Canada recommends healthy adults consume 150 mcg of iodine per day. Fortunately, most Canadians meet their iodine needs.

Iodine is found in seawater and some soils. There are many food sources of iodine including,

    • Shellfish 
    • Dairy 
    • Eggs 
    • Soy products 

Although it is important to get enough iodine in your diet to meet your needs, it is possible to have too much iodine. Consuming excess amounts of iodine may worsen your hypothyroid symptoms and increase your risk of developing an overactive thyroid (hyperthyroidism).

You can learn more about iodine, how much you need, and ways to include it in your diet here

Tips for Taking Thyroid Medication

If you’re taking thyroid medications, there are some dietary factors that you should be aware of.

It is important to always follow the instructions listed on your medications, including taking it with water, or on an empty stomach. After taking your medication, you may need to wait a few hours before taking other vitamins, minerals or medications. 

It is also a good idea to stay away from high-fibre foods, soy and walnuts after taking your thyroid medications, as these foods can reduce how much of the medication your body absorbs. 

If you’re taking thyroid medications, there are some foods that you may want to avoid for a few hours as they can impact the amount of medications your body absorbs. This includes, 

    • Grapefruit
    • High-fibre foods
    • Soy
    • Walnuts

Losing Weight with Hypothyroidism

Due to the role of thyroid hormone in metabolism, losing weight with hypothyroidism can be challenging. However, eating a healthy diet can help support your weight loss by supporting your metabolism, digestive health, heart and brain. A thyroid-healthy diet for weight loss includes,

    • Fruits, vegetables, nuts, and seeds
      • These contain essential vitamins and minerals, and are also sources of dietary fibre for digestive health
    • Lean protein such as eggs, poultry, lean meats, legumes (with their fibre), and fish and shellfish (with their omega-3s for heart and brain health)
    • Whole grains
      • Avoid gluten-containing grains if you have celiac disease
    • Heart-healthy oils like olive oil and avocado oil 

Try these recipes to help you lose weight with hypothyroidism:

You can find more nutrition tips for weight loss here

The Takeaway

Nutrition is important as a key factor on how to lose weight with hypothyroidism.  Knowing what to eat when your metabolism is slow can help you feel better, reduce your symptoms and help you lose weight. It’s also important to know what foods and drinks to avoid in the few hours before and after taking your medications. If you feel that you have symptoms that may be related to thyroid issues, speak with a healthcare provider. They will review your history, symptoms and help you decide if you need testing or treatment.

Never stop taking your medications without speaking with your doctor or pharmacist first. Working with a Registered Dietitian can help you establish a diet to support weight loss, even with an under-active thyroid.

Learn More About Weight Loss with Hypothyroidism

Need nutrition support and more information on how to lose weight with hypothyroidism? Book a FREE discovery call to learn how a Registered Dietitian can support your weight loss journey.