The thyroid hormones tend to get the most attention from the general public when it comes to weight loss. You hear people say all the time that they struggle with their weight because they have a “slow thyroid” or something to that effect. There is no doubt that the thyroid hormones play a major role in both weight loss and weight gain. They are significantly impacted by insulin, cortisol, leptin and the other metabolic hormones. Fortunately for most of us, there are ways to improve thyroid function naturally via the foods we eat and our lifestyle choices. Before we dive into what we can do, let’s establish a basic understanding of our thyroid hormones.
There are several thyroid hormones and they all function differently. They are produced and released based on signals the thyroid receives from the brain. Your thyroid is extremely sensitive to external inputs such as diet, environment, stress and toxins. Suboptimal diet and lifestyle choices can wreak havoc on your thyroid. If you take away one thing from this post, let it be that last sentence. Your diet and lifestyle have a MAJOR impact on your thyroid hormones. If you want optimal thyroid function, you need to eat and live accordingly!
Let’s talk about several thyroid hormones and how they are different from one another. First up is T3. T3 is the hormone we’re typically referring to when we think about metabolism. It is an active hormone that regulates your body’s fuel usage and temperature. T4 is the precursor to T3. In order to be impactful, T4 must first be successfully converted. Reverse T3 is a completely inactive thyroid hormone. All three of these hormones need to be successfully produced and they need to be produced in the proper ratios. If the overall amounts or the ratios or off, your thyroid function will be impaired.
Producing these hormones in adequate amounts and proper ratios is not all that is required for your thyroid to function optimally. The hormones must be successfully released from the cell and they must successfully attach to the precise receptor on the cell it is targeting. All those factors must be in place or else you’ll impair thyroid function.
Remember that your body is designed for survival. When you drastically reduce your calorie intake, your thyroid function slows down, taking your metabolism with it. Why? Because your body senses that fuel intake is limited and it doesn’t want to allow you to burn off your stored energy in case you need it. When you slash your calorie intake, your thyroid hormone production is reduced and much of the thyroid hormone you will produce and release will be the inactive form. This is your body’s way of conserving energy in times of perceived threat.
Similarly, when your leptin levels are low or you are resistant to leptin (due to being overweight or obese or consuming a very high carbohydrate diet), your thyroid function will decrease. Again, your body is either not getting signaled, or cannot properly receive the signal, that there is adequate stored energy in your body so it opts to downshift your metabolism to keep you “safe”.
High levels of estrogen can also slow your overall thyroid function. The presence of excess estrogen increases certain proteins that bind to your thyroid hormones and render them inactive. The thyroid is producing the hormones you need but they aren’t able to do their job because their receptor has been taken.
Finally, cortisol impacts your thyroid function. This relationship is a little more complicated. You’ll remember that in small, intermittent doses, cortisol is a significant fat loss ally. In these small, intermittent doses, cortisol can make your thyroid more efficient. Unfotunately, as is more often the case, excess cortisol inhibits the conversion of T4 (your inactive thyroid hormone) to T3, the active form. Why would we have excess cortisol? Chronic stress. Let it goooooo.
As you can see, there is a lot that can go wrong and impair thyroid function, leading to a slower, less efficient metabolism and an impaired ability to burn fat. Fortunately, there is a lot we can do to support the thyroid through diet, lifestyle and exercise.
First of all, proper thyroid function relies on several key nutrients. Here’s the thing – these nutrients MUST be consumed daily because our bodies have no ability to store them. Which nutrients am I talking about? Specifically iodine, zinc and selenium. If you aren’t sure if you are getting enough of these, your best bet is to take a high quality multivitamin. Nutrition is critical for optimal thyroid function.
As has been the case with all the hormones we’ve talked about so far, one of the most impactful changes we can make to maintain metabolic hormone balance is to control our blood sugar. Avoid dramatic peaks and valleys. The most straightforward and effective way to do this is to cut out processed foods and limit wheat and grain products. In fact, avoiding them completely is the ideal. Start by cutting out processed foods and focusing on vegetables, meat, fish, poultry, nuts, seeds and some fruit. However, as you make this transition be sure you aren’t drastically cutting your calories. Remember that dropping your calories slows your thyroid function. Eat when you’re hungry, stop when you’re full.
Finally, lifting heavy weights and high intensity interval type training improves thyroid function by increasing the sensitivity of the cellular receptors to which your thyroid hormones need to attach to function.
I hope you’re beginning to see a trend as it relates to balancing and optimizing your metabolic hormones. They all work differently but they all impact each other. Not only that, they all benefit significantly from a healthy diet that minimizes the blood sugar spikes that result from processed foods, wheat and grain products.
If you want to know more about hormones and fat loss, check out my free podcast!
There’s also my new ebook! 50 pages of information and specific diet & lifestyle strategies to help you naturally balance your hormones and get into fat burning mode!