Discover why thyroid problems can limit your weight loss efforts

One of the frustrations I see in my autoimmune clients is their inability to lose weight. Adipose tissue in and of itself is inflammatory, which can worsen autoimmune symptoms and affect the joints, making movement more difficult. 


With weight targets in mind, you may think that more exercise will help, but it can actually add fuel to the fire and worsen symptoms, leading to more inflammation and weight gain rather than loss. 

One common but often overlooked factor is thyroid dysfunction, specifically hypothyroidism. Let’s delve into how your thyroid health can impact your weight loss efforts.

How does impaired thyroid health lead to weight gain?

Understanding the connection between thyroid health and weight management and adopting appropriate dietary and lifestyle strategies can significantly aid weight loss efforts (without intense gym training!).

The thyroid gland, located at the base of your neck, is essential for regulating metabolism by producing hormones like thyroxine (T4) and triiodothyronine (T3). These hormones influence how your body uses energy. 

Autoimmune diseases, such as Hashimoto’s thyroiditis, can lead to hypothyroidism, where the immune system attacks the thyroid gland, reducing its ability to produce these critical hormones.

When the thyroid gland is underactive, the metabolic rate slows down. This means your body burns fewer calories both at rest and during physical activity. For those with autoimmune thyroiditis, this can result in persistent fatigue, weight gain, and difficulty losing weight despite following standard weight-loss protocols.

How do you know if you have thyroid issues?

Knowing whether you have low thyroid function can take time to diagnose. I often work with clients who have been told by their doctor that their thyroid hormone levels are within normal range, but the marker often tested is thyroid stimulating hormone (TSH), which doesn’t give you the full picture. 

Also, when clients have antibodies to their thyroid, such as thyroid peroxidase antibodies and thyroglobulin antibodies, but their TSH is in range, their symptoms, such as cold intolerance, hair loss and inability to lose weight, are often overlooked, but this may be an indication of subclinical hypothyroidism, and the start of Hashimoto’s thyroiditis.

If you are experiencing these symptoms, it is essential that you get a full thyroid panel so you understand your current free thyroid hormone levels, which are the most important factor in your thyroid health and how you feel. 

I recently worked with a client experiencing hair loss for many years. Her thyroid health had been checked, but not her free T3 levels, and when we ran a full panel, we found these were really low, indicating that the symptoms she was experiencing were related to her thyroid hormone levels.

What are the best nutrients to support thyroid function?

Regarding diet, there are numerous factors to consider regarding your thyroid health. Nourishment rather than restriction is vital, which is where some people go wrong when looking to lose weight. 

Iodine is crucial for thyroid hormone production, and iodine deficiency is worsening due to changes in dietary habits, such as reduced consumption of iodised salt and iodine-rich foods like seafood and dairy. 

Additionally, soil depletion and changes in agricultural practices have led to lower iodine levels in crops. Increased reliance on processed foods, which often lack adequate iodine fortification, exacerbates the problem. 

To support your thyroid function, incorporate iodine-rich foods such as seaweed, fish, dairy products, and eggs into your diet. I particularly like adding seaweed flakes to salads and soups for extra nutrient density. 

Selenium helps convert T4 into T3, the active form of thyroid hormone, and this can often be an issue when someone has subclinical hypothyroidism. 

When you are selenium deficient, your T4 levels might be in range, but the active form of T3 has the most important role, so it is vital to keep your levels optimal. 

Good sources of selenium include Brazil nuts and seafood such as tuna, sardines, shrimp, and salmon. Other excellent sources are lean meats like chicken and turkey and plant-based options like sunflower seeds, brown rice, and lentils. 

Zinc also supports thyroid function. Foods like pumpkin seeds, chickpeas, and lentils are excellent sources.

A balanced gut microbiome is also crucial for a healthy metabolism and thyroid function. Gut dysbiosis, an imbalance in the gut microbiota, can impair the conversion of T4 to T3 by affecting the enzymes and pathways involved in this process. 

Healthy gut bacteria play a crucial role in converting the inactive thyroid hormone T4 to the active T3 form. In addition, dysbiosis can lead to inflammation and increased intestinal permeability, further disrupting this conversion and potentially leading to thyroid dysfunction. 

If you would like to explore your gut health, you can learn more about the Gut Health Testing Package I offer here.

Some research suggests that those with autoimmune thyroiditis may benefit from a gluten-free diet, as gluten can trigger an immune response that exacerbates thyroid problems. Going gluten-free may be beneficial if you have thyroid issues and are struggling to lose weight. 

Lifestyle practices to optimise thyroid function and weight loss

To boost metabolism, incorporate a mix of cardiovascular, strength, and flexibility exercises. Aim for at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous activity each week, along with muscle-strengthening activities two or more days a week. If you are struggling with mobility at the moment, take it a step at a time (literally) and aim to increase your step count daily, or set a goal for every day such as 10,000 steps. 

Poor sleep can exacerbate thyroid symptoms and contribute to weight gain. Aim for 7-9 hours of quality sleep per night, and practice good sleep habits, such as going to bed at the same time routinely and sleeping in a dark and well-ventilated room without distractions such as your phone or television. 

Chronic stress can impact thyroid function and overall health. Yoga, meditation, and deep-breathing exercises can help manage stress levels. I like to do five minutes of deep breathing exercises throughout the day to help manage my overall stress levels, and it works a treat.

Lastly, one of the simplest ways to support weight and thyroid health is staying well-hydrated, which supports metabolic processes and overall health. Aim to drink at least 8-10 glasses of water a day.

Managing weight with thyroid dysfunction, particularly in the context of an autoimmune disease, requires a comprehensive approach that includes dietary modifications, regular exercise, stress management, and ongoing review of your thyroid hormone levels.  

Addressing these areas can optimise thyroid function and enhance weight loss efforts, even in the face of autoimmune challenges. What small changes can you make today to support your metabolism and keep your weight in check in a more sustainable and healthy way?

If you would like to learn more about my 1-2-1 services, you can book a free initial consultation with me. 

The views expressed in this article are those of the author. All articles published on Nutritionist Resource are reviewed by our editorial team.

Share this article with a friend
London W1G & Harrogate HG1
Written by V. J. Hamilton, Autoimmune Disease Expert | BSc (Immunology), DipION, mBANT
London W1G & Harrogate HG1

After 25 years of suffering from multiple autoimmune conditions including alopecia, psoriasis and CFS, VJ discovered she could uncover the root cause of her issues to transform her health & live without symptoms.

VJ now uses these same principles to help those with autoimmune diseases regain their strength & live a whole and symptom-free life.

Show comments

Find a nutritionist dealing with Thyroid problems

All nutrition professionals are verified

All nutrition professionals are verified