Updated 9/06/2020

Julie came to see me recently because she’d been struggling with unexplained weight gain. She hadn’t changed a single thing about the way she was eating or exercising and was increasingly frustrated that the number on the scale kept creeping up. She tried eating less and exercising more, but those extra pounds just wouldn’t come off. As we talked, she wondered “Is it my thyroid?”

That’s a good question to ask, and often the answer is yes. But the connection between thyroid and weight isn’t simple, nor is there a simple solution.

Thyroid function and metabolism are intimately linked; thyroid hormones are responsible for regulating calorie consumption. But other body mechanisms, including neurotransmitters, reproductive hormones, and adrenal glands, must also be working properly for your thyroid to remain healthy.

Once you understand the way it all works you can find ways to address the issue and drop the extra weight. Let’s take a look at how thyroid issues impact weight gain, why women experience thyroid problems, and how hypothyroidism in particular can cause weight problems. Then we’ll look at some solutions.

Thyroid and weight gain

The basal metabolic rate is how many calories your body needs simply to continue to function while at rest. A low basal rate can create weight gain and difficulty losing weight

Many women with underactive thyroids (hypothyroidism) have low basal metabolic rates. That makes sense, since the thyroid is responsible for regulating metabolism. In hyperthyroidism, which means overproduction of thyroid hormones, the opposite is usually true. Occasionally, an overactive thyroid can mimic an underactive thyroid by causing weight gain, but more often people with hyperthyroidism lose weight.

Although weight gain is common in hypothyroidism, a small percentage of women do not gain weight. That’s in part because we all have our own unique biochemistry, and our bodies operate in very different ways. The quality of calories consumed, and how the body uses them is also a factor.

As I’ve said, low levels of thyroid hormone can cause weight gain. On the flip side, weight gain can cause thyroid imbalances. It’s a crazy cycle that is hard to decipher!

Because your thyroid doesn’t operate in isolation, it’s important to pay attention to the other systems I mentioned earlier. Imbalances or dysfunction in any one of these can have an impact on weight, and improper thyroid function can create those problems in these other systems. That means weight gain is even more likely when more than one system is out of sync!

Restricting calories severely may seem like the obvious solution if you have a low basal metabolic rate, but the “metabolic burn” often falls as you reduce calories. That’s why women with hypothyroidism can gain weight even when they’re hardly eating anything! In order to fix your metabolism, you have to understand your entire health picture, not just your thyroid.

Thyroid in women

Although men can also suffer from hypothyroidism, the condition occurs more frequently in women. And far more women with thyroid issues experience weight gain than men who have thyroid difficulties. Thyroid problems within the gland itself often go unnoticed until a broader pattern of hormonal imbalance develops. That’s why thyroid issues, menopause and weight gain often crop up at the same time for women.

Why do women experience low thyroid and weight gain with such frequency?

While there are multiple reasons, the primary factors include:

  • Yo-Yo dieting. So many women spend a large portion of their lives bouncing between eating whatever they want and severely restricting calories. This “feast or fast” cycle undermines your metabolism and decreases your metabolic rate, a compounding factor for the thyroid, especially during perimenopause.
  • Women tend to internalize stress, which affects their adrenal, brain, and thyroid function, among other things. This results in increased cravings for sweets and simple carbs to provide instant energy and boost “feel good” hormones.
  • Women experience monthly hormonal fluctuations that affect their biochemistry.

What You Can Do About Hypothyroidism and Weight Gain

Because the thyroid is so often behind unexplained weight gain in women, it’s an obvious place to begin. Talk to your health care practitioner about testing levels of thyroid hormones, including T3 and T4, Reverse T3 as well as TSH (thyroid stimulating hormone).

It’s important to test all four since the way they interact makes a big difference in your body. TSH, produced by the pituitary gland, is responsible for letting the thyroid know how much T3 and T4 should be released. Prior to that, the hypothalamus produces TRH (TSH releasing hormone) to tell the pituitary gland how much TSH is required.

That means that imbalances can start in the brain, if those glands aren’t doing their jobs properly. So, you can’t rely on thyroid hormones alone to give you the complete picture of what’s happening. Knowing that T3 and T4 levels are too low indicates a problem in your thyroid gland, but that alone won’t tell you where the problem begins. Also elevated Reverse T3 acts like the breaks on the thyroid and often happens when someone has done too much Yo-Yo dieting.

Testing is the best first step, but I always caution women that they could test within the “normal” range of traditional medical standards still need thyroid support. That’s because conventional medicine is focused on disease and won’t dig deeper if the numbers fall in that normal range. But normal can be deceiving and every woman is different. For some, even slightly elevated TSH can impact metabolism, resulting in weight gain.

Begin with nutrition

When a woman’s body is more sensitive to slight imbalances, they could need supplemental nutrients such as selenium and a regular meal plan that balances a proper ratio of protein to carbohydrates. This increases metabolic functioning and they begin to lose weight.

I always say that food is the best medicine there is, so I always begin treatment for thyroid imbalances by suggesting changes in diet. Here are a few specific things to think about:

  • Good nutrition begins with whole foods. Processing depletes nutrients. We should be eating to supply our bodies with all of the essential nutrients it needs, and the best way to do that is eat a wide variety of whole foods. Fruits and vegetables, lean meats, fish, nuts and seeds that haven’t been processed are all great choices!
  • Stick to an eating schedule. Having a schedule often means you’ll set aside the time you need to eat instead of relying on grabbing something when you have a free minute. Too much time between meals or snacks can strain your thyroid gland. Breakfast is important when working to support the thyroid. Eat within an hour of waking to get your metabolism going.
  • Don’t forget the protein. Your thyroid hormones are transported by protein to the tissues in your body. Protein also helps regulate thyroid function.
  • Fiber is also important. You don’t have to get fiber from grains, however. Grains can actually exacerbate thyroid issues. Fruits and vegetables are a better option for getting enough fiber.
  • Beware food that impedes thyroid function. Some foods can really take a toll on the thyroid, especially when it’s already imbalanced. Research “goitrogens.” Some foods, such as soy, sweet potatoes, and cruciferous vegetables are well known goitrogenic foods.You can still eat these, but it’s best to steam or cook them to reduce goitrogens. . Cut out gluten, sugar, artificial sweeteners, alcohol and processed foods that will make balancing the thyroid more difficult.

Consider a little extra support

It is so difficult to get the nutrients your body needs from food alone. Sadly, commercially grown produce just doesn’t have the nutrients it used to, especially if you aren’t buying organic.

Because of this, I recommend that all women take a high quality multivitamin-mineral supplement. It’s important that it contains both iodine and selenium, which are essential for thyroid support. Other key ingredients include zinc, iron and copper.

Beyond the multivitamin, when the thyroid is struggling to function properly, you can add a supplement specifically formulated to offer extra support. My Thyroid Support formula is designed to support healthy cortisol, insulin and blood glucose levels – all of which impact proper thyroid function. Ingredients include both iodine and selenium, along with tyrosine and copper elements to support the “feel good” compounds dopamine and norepinephrine.

My Thyroid Health Program, which includes my Multi Essentials, Thyroid Support, and EPA/DHA support, offers the full range of nutrients to keep your thyroid at peak performance.

Look at bio-identical hormones

For some women, stubborn weight will linger even with all of the efforts to support your body’s nutrient needs. In those cases, I sometimes recommend a low-dose, bio-identical thyroid replacement hormone.

Individual women need individual treatment

The endocrinology field is ripe with controversy over the best ways to treat hypothyroidism. Some believe that if a patient tests within the normal range but exhibit very low basal metabolic rates and very low basal temperatures thyroid supplementation is necessary. Others argue that only patients with significant abnormalities should be supported with thyroid hormones.

In my practice, I look at each woman as the unique individual that she is. I examine all relevant factors before deciding if medication is warranted. Weight gain alone won’t tell me that a woman has a thyroid abnormality, but it is a relevant piece of the puzzle. When women, like Julie, can’t shed excess weight no matter what they try, it’s essential to rule out thyroid imbalances. If imbalances are present and not addressed, all efforts to lose weight are likely to fail. But there is hope! The greatest success is found through a holistic, natural approach that considers thyroid function as an integral part of your overall hormonal balance.

For more information on this topic, read our many informative articles in the Thyroid Health section of our Health Library.