Because the thyroid gland determines how efficiently we burn calories, it plays an essential role in helping us maintain a healthy weight. “The thyroid hormone is a master hormone that regulates metabolism,” explains functional-medicine nutritionist Cindi Lockhart, RDN, LD, IFNCP.
But the vast majority of the estimated 60 million American adults with thyroid problems don’t know they have them, which makes “missing” the operative word when it comes to this missing link. (For a list of symptoms, see “Repair Your Thyroid.”)
There are a couple of reasons so many thyroid cases go undiagnosed. Many doctors often use outdated reference ranges when assessing thyroid lab results, unaware that the ranges once considered normal have been narrowed in recent years, notes functional-medicine endocrinologist Sara Gottfried, MD, in her book The Hormone Cure.
And many practitioners run only one test — measuring thyroid stimulating hormone, or TSH — to assess a patient’s thyroid health. Though TSH is important, it doesn’t provide enough information on its own to rule out dysfunction.
“Only testing TSH is like sending cans of food to a country in need — but not sending a can opener,” says Lockhart. “We have to consider the whole pathway.”
That wider pathway includes checking the thyroid hormones free T3, free T4, and reverse T3, as well as the thyroid antibodies thyroid peroxidase and thyroglobulin. These antibodies signal that the body is attacking the thyroid. They can be present for many years before TSH moves out of a healthy range.
“In my practice, we use seven different measures for thyroid health,” says integrative physician Akil Palanisamy, MD, author of The Paleovedic Diet. And when tests turn up thyroid dysfunction in its early stages, he notes, it is much easier to address without medication.
If you suspect your thyroid might be playing a role in weight-loss resistance, ask your doctor to run a full thyroid panel. Together, these lab numbers will provide a more accurate picture of your thyroid health and allow you to address subtle imbalances or early-stage dysfunction before problems worsen.
This originally appeared as “Missing Link No. 5: Healthy Thyroid Function” in “9 Missing Links to Weight Loss” in the January-February 2019 print issue of Experience Life.