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Thyroid Dysfunction

Written by Cindi Lockhart, RD, LD - Weight Loss Coaching Program Manager

Low thyroid – often the first to blame in the struggle to lose weight!  Thyroid is the most important organ in the body for managing both weight and body fat.  An estimated 20 million Americans have some form of thyroid disease, with up to 60% completely unaware that this is the case.[i]  Not only is thyroid dysfunction the most unidentified and mistreated health condition, it increases the risk of other serious conditions when left undiagnosed.  Women have been found to be five to eight times more likely than men to have thyroid dysfunction.  The thyroid is a small gland found in the neck with a large function in the body.  It is responsible for energy production and metabolism. 

Thyroid stimulating hormone (TSH) measures the pituitary gland function in response to circulating T4 levels and has in inverse relation to thyroid function – the higher the number, the lower the thyroid function.  Free T4 measures unbound, active thyroid hormone in the body.  With suboptimal production of T4, metabolism can drop by as much as 40%.  Free T3 needs to be converted from T4 in the liver and is up to five times as metabolically active as T4. 

So if you feel sluggish and you struggle to lose weight, why wouldn’t you blame your thyroid?  Today, we will be exploring the symptoms of low thyroid function, factors that contribute to it’s malfunction, effects on our health, best ways to test for function, and how to improve thyroid health through diet, lifestyle, and supplementation.

Symptoms of low thyroid function

The thyroid is responsible for metabolism and energy production, so it has a dramatic effect on one’s level of energy and ability to lose weight. Some other symptoms include cold intolerance (always feeling cold and hands/feet cold to the touch), constipation, aching muscles, thin, brittle and dry hair, skin and nails, inability to sweat, low heart rate and/or blood pressure, low mood/depression, menstrual irregularities, and low basal body temperature less than 98°.  Whew!!!  That was truly a mouthful.  Do any of the above symptoms sound like you?  If so, read on.

Factors that contribute to thyroid dysfunction

What causes the thyroid to malfunction?  The thyroid gland is quite sensitive to external stimuli as well as closely integrated with other hormonal systems in the body, so if one hormone gets off track it can easily pull another along with it.  Let’s explore further.

Stress is one of the most common external (or internal) factors disrupting thyroid function.  When under chronic stress, the adrenal glands produce excess cortisol, which requires tyrosine, an amino acid also needed for thyroid hormone production.  Cortisol also inhibits the conversion of Tto T3 which slows metabolism.   

Another disruptor is toxins – environmental chemicals, pesticides, and heavy metals.  They bind to thyroid receptors and block the thyroid hormone from its normal function.  Mercury decreases iodine uptake, which is essential to optimal thyroid hormone production.[ii]   

Nutrient deficiencies, specifically the minerals iodine, zinc, chromium  and selenium as well as the amino acid tyrosine impact our ability to produce thyroid hormone and allow for adequate functioning of the hormone.  How do nutrient deficiencies occur?  For starters, an overly processed diet destroys these nutrients in production, taking oral contraceptives depletes our bodies store of these nutrients, and poor gut flora balance – too many unhealthy compared to healthy bacteria in our colon.  This balance gets disrupted by excess stress, processed foods, and antibiotics in our food or medicine to name a few. 

Effects of low thyroid function

Fatigue and free radical damage occur with suboptimal T4 and T3 hormone levels.  These hormones are needed to use oxygen during aerobic respiration and when they are low, energy is depleted, excess oxygen builds up in the cells, the number of mitochondria (energy powerhouses in every cell of our body) decrease, and free radical damage occurs.  This is essentially “rusting” at our cell level and most, if not all, major health conditions are associated with free radical damage – cancer, heart disease, diabetes, arthritis, hypertension, accelerated aging. 

In regards to heart disease, fat metabolism is a function of thyroid and when the thyroid isn’t working right, fat metabolism is stimulated, which can lead to elevated blood lipids (hyperlipidemia).  In regards to diabetes, the thyroid gland assists the liver and pancreas with blood sugar regulation and the cell’s response to insulin.  When thyroid hormone levels are low, this function is challenged and leads to poor blood sugar control and insulin receptivity at the cell level.  Elevated insulin levels cause the body to store fat and shut down the ability to burn fat. 

Testing thyroid function

To begin addressing the function of your thyroid gland, take your basal morning temperature for a week under your arm.  Check to see if it is consistently below 98°. If it is, or even if it isn’t but you have many of the above mentioned symptoms, get your blood tested for thyroid hormones.  I would suggest getting the complete picture with TSH, Free T4, Free T3, and TPO (thyroid peroxidase antibodies, which may indicate more of an autoimmune response to thyroid function).  Make sure you have the “free”, active, unbound hormone levels tested rather than the bound forms.  Life Time Fitness offers an inexpensive thyroid function test called Energy & Metabolism for $148, which tests all the above factors plus ferritin levels (iron storage).  See your fitness professional for more details at the club.

Improving thyroid health

While waiting for your blood test results, there are a variety of actions you can take to improve your thyroid function.

  • Eat a natural, whole food, unprocessed diet – as organic as able to decrease the hormones, antibiotics, and chemicals/pesticides
  • Drink reverse osmosis water – eliminates heavy metals, chlorine and fluoride from conventional water sources that disrupt thyroid function
  • Eliminate soy protein in diet – a strong plant estrogen source that competes for the same receptor sites as thyroid
  • Limit intake of large fish species (canned/fresh tuna, swordfish, pike, walleye) – mercury content can disrupt thyroid function
  • Get regular exercise – assists with body composition, energy, and weight
  • Get 7-8 hours of uninterrupted sleep per night
  • Manage stress – yoga, meditation, journaling, mind-body programs
  • Dry sauna at least 3 days/week – assists with chemical detoxification and thyroid function support
  • Avoid plastics (BPA – thyroid disruptor) – storage containers, water bottles, heating/freezing food or beverages in plastic
  • Take a high-quality multivitamin/mineral with iodine, chromium, zinc, and selenium
  • Take a high-quality Omega 3 fish oil supplement
  • Other supplements to consider:
    • Probiotic
    • L-tyrosine


The thyroid gland is essential for optimizing our health, metabolism, weight, and body composition.  Several aspects of our current American culture and lifestyle can quickly disrupt its function and increase our risk for serious health conditions.  Make sure you address your thyroid function and start making lifestyle changes to impact how this little significant gland works in your body.

[i] The American Thyroid Association

[ii] Queen, HL. Chronic Mercury Toxicity: New Hope for an Endemic Disease, (Colorado Springs: Queen and Company, 1988): 32-40, 47.

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Reader Comments (4)

Cindi, Thank you for the informative and well written article. I was diagnosed with low-thyoid function in 2008 and continue to be amazed by the lack of information that is available about it. What is specifically lacking is what can you do (in addition to taking replacement horomone) to improve and possibly reverse the condition. Articles like yours are incredibly beneficial. Thank you.

December 13, 2011 | Unregistered CommenterNancy Robinson

Hi Nancy:
Thank you for your message. I am happy to hear that you are benefiting from our articles. Have a great holiday season!

December 14, 2011 | Unregistered CommenterCindi Lockhart, RD


Thanks for this wonderful article. It was Full of valuable information. I've struggled with Hashimoto's (autoimmune hypothyroid) for over 10 years. It is such an insidious disease! We all need as many weapons as possible to fight it. You gave some very practical and easy to follow advice. It's absolutely amazing to me that I get the most, by far, useable information from this magazine. Thank you so much for your contributions. Have a great 2012!

December 26, 2011 | Unregistered Commenterkadelmann

Hi Kerry:
Thank you for your very kind response. I am so happy to hear that you are receiving great benefit from our articles. Our mission is to make sure our readers learn as much about themselves and their health in a practical and realistic manner. I wish you the very best with your Hashimotos - I would love to hear back from you regarding the impact that these tips may have on you. Merry Christmas & have a healthy 2012!!

December 26, 2011 | Unregistered CommenterCindi Lockhart

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