Thyroid, Your Weight, and Metabolism

Sara Gottfried MD | Women's Health |Thyroid, Your Weight, and MetabolismHow’s your thyroid? Do you know your level of thyroid stimulating hormone (TSH)? It’s estimated that about 60 million Americans, both men and women, struggle with thyroid problems. Most don’t know it. Women struggle with their thyroid more than men. A common sign of a thyroid problem is difficulty losing weight, despite doing all the ‘right things’ in terms of diet and exercise. It’s what I refer to as weight-loss resistance. Does this sound familiar? Read on to learn more about how thyroid affects your weight and metabolism.

What Is the Thyroid Gland and What Does It Do?

The thyroid gland secretes hormones that regulate the activities of almost every cell in our bodies. It controls the body’s sensitivity to other hormones, such as estrogen and cortisol. It regulates how quickly we burn calories and maintains our metabolism, which explains why weight control is such a problem when the thyroid is out of whack. In other words, your thyroid is your very own metabolic thermostat.

Why Do Doctors Underdiagnose Thyroid Issues?

Conventional physicians often respond with skepticism, derision, and even hostility to women who earnestly ask for thyroid help. There are a couple of reasons for this. One is that doctors are well-intentioned but woefully underinformed about the thyroid, in particular what are considered to be the normal ranges for thyroid hormones.

Another reason is that women are disempowered in the doctor’s office. I’ve heard countless stories from my own patients as well as from my online community about women getting dismissed with a pat on the back and the remark, “You’re just getting older,” in response to thyroid complaints. For years now, I’ve been on a mission to amplify the message around thyroid health and help people struggling unnecessarily due to low thyroid function.

What Are the Causes of Thyroid Dysfunction?

One of the most common causes of low thyroid function is autoimmune thyroiditis, commonly known as Hashimoto’s or ‘Hashi’s’ for short. With this disease, your body’s own immune system attacks the thyroid gland, causing inflammation and an overproduction of thyroid hormones. This is followed by underproduction of the thyroid hormones. Many women have “flares” of increased immune attack. It is diagnosed with a blood test to check for antibodies against the thyroid, thyroid peroxidase antibodies, and anti-thyroglobulin antibodies.

Selenium deficiency can also lead to low thyroid function. I believe selenium is the most important mineral for your thyroid health, and unless you’re eating from composted soil, I doubt you’re getting enough from your food.

As our exposure to endocrine disruptors has increased, so has the incidence of thyroid disease in the United States, particularly for thyroid cancer and thyroid autoimmune disease.

Postpartum Hypothyroidism

Hypothyroidism is one of the main imbalances women are at risk for postpartum. After giving birth, about 7 percent of women develop what’s called postpartum thyroiditis, when the immune system attacks the thyroid, causing mood swings, lethargy, thinning hair, and difficulty with weight loss. Women with baseline thyroid antibodies before pregnancy are much more likely to develop postpartum thyroiditis.

The Connection between Perimenopause, Thyroid, and Weight Gain

If you are entering the midlife years, you have probably noticed that it’s no longer so easy for you to maintain your weight and what worked in the past, no longer has the same effect. Why do women seem to gain weight almost overnight as they move closer to menopause?

One of the main reasons for weight gain starting in the perimenopausal years is the slowing of metabolism. You can attribute the decrease in metabolism to thyropause, changes in estrogen levels, and increased cortisol.

As discussed earlier, thyroid hormones control how we burn calories and keep our metabolism from getting too sluggish. They often get out of balance as we get older. This is a trend that has been labeled ‘thyropause.’ Weight gain is a result of an underactive thyroid, as well as weakness and fatigue.

Ketogenic Diets May Affect the Thyroid

To combat the weight gain that seemingly appears overnight, particularly around the belly region, women start restrictive diets to reduce carbohydrates. It’s why many women turn to the ketogenic diet. They see it work so well for the male counterparts but it turns out keto is not as successful in women. One of the goals of my new book WOMEN, FOOD, AND HORMONES, was to discover why a low carb high fat diet like keto didn’t offer women the same weight loss results as men.

Women Need Carbs

It turns out that women need carbs for their thyroid. Carb restriction can affect levels of the thyroid hormone, reverse T3. Reverse T3 (rT3) is an inactive metabolite of T4 and provides a mechanism to slow down metabolism in order to save energy. It provides a feedback system to keep you in balance under normal conditions. However, if your body is stressed or on a calorie-restricted diet, a signal is sent to change the ratio, and you produce more reverse T3 and your metabolism slows. This is a common issue in women on a ketogenic diet and rT3 is one of the biomarkers that I check with patients who tell me they have tried keto and it didn’t work for them.

Part of the reason I wrote my new book WOMEN, FOOD, AND HORMONES was to find a better-formulated plan for these patients, where we still work with ketosis for weight loss or whatever their health goal is but we modify the plan. For example, I encourage women on the plan to eat plenty of prebiotic carbohydrates and help them explore what their carbohydrate tolerance is as a way of helping with their thyroid function.

If you’ve tried keto before and found it didn’t work for you, my modified ketogenic diet plan offers a solution.