When you hear the word “metabolism,” what does it make you think of? If you’re thinking “how easily someone can stay skinny,” you’re not alone. But the metabolism is so much more than that.
Your metabolism is the sum of every function in your body, from digestion and hormone health to thyroid function and energy production. It’s one of the greatest tools for assessing overall health. When the metabolism slows down, it slows down every function in our body. This includes digestion, hormone production, energy production, and more.
Simply being lean and being able to eat whatever you want does not equal a high-functioning metabolism. Let me restate that. Being thin and “fit” does not necessarily equate to being healthy. If your jean size isn’t a good predictor of a healthy metabolism, then what is?
Signs your metabolism is working optimally:
While there are many ways to access health, some easy tools for you to track at home are listed below. These signs give you a picture of how well your thyroid and metabolism are functioning:
- You feel energized throughout the day
- Your mood is reflective of your situation (you can feel happy and positive when things are going well and don’t feel down all the time)
- Your digestion is working well and you have 1-3 bowel movements per day
- You have a healthy libido
- You have a warm body
- Your hair is thick and shiny
- Your skin is healthy and not too dry or too oily
- You have great circulation
- You mostly get deep, restorative sleep
- You can easily maintain lean muscle mass
The Thyroid Gland: Your Source of Metabolic Power
The thyroid gland is a butterfly-shaped organ located at the front of your neck. It is the master conductor of every metabolic process in your body. Its primary function is to make thyroid hormones, T4 and T3, the active form of thyroid hormone. A well-functioning thyroid is essential for a high-functioning metabolism.
Every cell in your body has receptors for hormones produced by your thyroid.  Your thyroid is pretty busy running the metabolic show and is in charge of:
- Regulating your metabolism
- Stimulating chemical reactions in cells
- Stimulating glucose absorption
- Increasing the rate of nutrient absorption in the small intestine
- The motility of the intestinal tract
- Gallbladder and liver function
- The rate of energy and heat production in cells
- Regulation of muscle function, sleep quality, hormone production, and respiration rate
- And So. Much. More.
So how do you know if your thyroid is working optimally? A lot of the same signs of a healthy metabolism! Since the thyroid drives metabolic function, the same indicators of metabolic health are the signs of a well-functioning thyroid.
Signs and symptoms of an slugglish thyroid:
Likewise, your body gives you clues when your thyroid isn’t functioning optimally. These can include:
- Cold hands and feet
- Slow digestion and/or constipation
- Dry skin
- Loss of outer third of the eyebrow
- Brain fog
- Weight gain
- Muscle stiffness and pain
- Low energy and fatigue
The good news is there are many simple, inexpensive ways you can begin supporting your thyroid today.
Modern foods and lifestyles can impair metabolism and thyroid function:
One of the first steps to improving thyroid function and strengthening the metabolism is to identify anything that might be slowing it down.
Many things can interfere with metabolism and thyroid function, including:
The thyroid needs copper, selenium, zinc, magnesium, and iodine to function properly. A deficiency in any of these nutrients can lead to thyroid issues and hypothyroidism.
When you’re chronically stressed, your body is concerned with survival. To ensure that you survive, your body will upregulate all of your survival mechanisms and hormones like adrenaline and cortisol. Your body won’t prioritize things like hormone production, and that includes thyroid hormone. The thyroid and adrenal glands work in tandem. If the adrenals are constantly pumping out cortisol and adrenaline to keep you alive, thyroid function slows down.
Exposure to chemicals and toxic compounds from food and the environment (think beauty products, plastics, harmful household cleaners, etc.)
Industrial chemicals like perchlorate, polychlorinated biphenyls (PCBs), and dioxin can all impact thyroid function, even when exposed to small amounts. [2, 3]
Pesticides and herbicides can downregulate the thyroid in a number of ways, including blocking the thyroid’s uptake of iodine and reducing cellular uptake of thyroid hormone.[4, 5]
Many chemicals found in everyday household products can seriously disrupt thyroid function. Flame retardants found in mattresses, children’s clothing, furniture, and carpets are serious endocrine disruptors. Bisphenol A (BPA) and phthalates, found in plastics, as well as triclosan (a chemical in antibacterial hand soap), and chemicals in non-stick cookware all block thyroid function. (6, 7, 8, 9, 10)
Infections from parasites, bacteria, fungus, and viruses, especially gut infections.
The health of your gut impacts thyroid function and vice versa. Healthy bacteria are actually involved in the conversion of thyroid hormone to its active form. Since your gut and immune system are so intricately intertwined, having gut issues like leaky gut can lead to thyroid issues, including Hashimoto’s. [10a]
The thyroid is intimately connected to the HPA axis. When under stress, your body releases inflammatory cytokines that interfere with the pituitary and hypothalamus. Since the pituitary and hypothalamus are responsible for producing thyrotropin-releasing hormone (TRH) and thyroxine-stimulating hormone (TSH), when they aren’t functioning optimally, neither is the thyroid, leading to lower levels of T3 and T4.
Heavy metals like mercury, lead, cadmium, and aluminum are increasingly common in our environment, food, water, pharmaceuticals, and/or personal products. The accumulation of heavy metals can impact thyroid function in many ways. [11, 12, 13]
Nutrients for Thyroid Health
A well-functioning thyroid is essential for a high-functioning metabolism. An organ in charge of so many important metabolic processes in your body can need a lot of support.
Copper, selenium, zinc, magnesium, and iodine are all essential nutrients for optimal thyroid function. But before you go out and buy a bunch of supplements, it is best and easiest to get these nutrients from food. Food comes in whole forms and contains the nutrients needed for thyroid function. These foods also all the necessary enzymes and cofactors needed to keep things in balance. Food first!
Taking nutrients in isolated supplement form can often cause other nutrient imbalances. Most supplements are not in their most bioavailable forms and lack the necessary co-factors for your body to make use of that vitamin or mineral. So, food first!
Best food sources of thyroid-supportive nutrients:
oysters, shellfish, grass-fed beef liver, potatoes, dates
shellfish, beef, liver, lamb, chicken
oysters, beef, lamb, shrimp
raw dairy from grass-fed cows, kelp, seaweed
coffee, dark chocolate, fruits, bone broth, very well-cooked greens
A note on magnesium: Stress burns through magnesium crazy fast and considering we are more stressed than ever, this nutrient is of especially high need. Not only that but modern-day soil is so depleted of this mineral (and others) that it can be near impossible to get enough from food. Almost all of my clients (and myself) supplement with at least one form of magnesium.
Foods that work against optimal thyroid function include:
- Processed foods
- Seed oils (PUFA-rich oils from grapeseed, corn, canola, soy, rice bran, safflower, sunflower, etc.)
- Raw goitrogenic vegetables (kale, broccoli, cauliflower, brussels sprouts, etc.)
- Legumes that have not been soaked and prepared properly
- Excessive nuts and seeds
Lifestyle support for optimal metabolism and thyroid function:
- Eat the right foods, and eat often. Focus on nutrients from food first. The thyroid needs selenium, zinc, magnesium, iodine, and copper to function optimally. Getting these nutrients from food is ideal to keep other vitamins and minerals in balance.
- Eat plenty of high-quality animal protein, collagen, gelatin, fruits, well-cooked root vegetables, honey, daily raw carrot salads, beef liver, oysters, and raw dairy. These foods are all very pro-thyroid and rich in thyroid-supporting nutrients.
- Reduce or avoid PUFA intake from vegetable and seed oils. Polyunsaturated fats slow down the metabolism and put extra stress on your thyroid. High-PUFA fats include sunflower oil, safflower oil, vegetable oil, corn oil, soybean oil, canola oil, grapeseed oil, rice bran oil, and almond oil. Nuts, seeds, grains, and legumes also have high amounts of PUFAs, so they should be consumed in moderation.
- Eat the right kinds of fats. Saturated fats are pro-metabolism and help increase the metabolic rate and are protective against the oxidation that comes from PUFAs. Eggs, ghee, butter, coconut oil, bison, lamb, beef, and dairy are all great sources of saturated fat. Saturated fats are also great, stable fats for cooking at higher temperatures.
- Reduce your stress. Stress is one of the most harmful things for your thyroid and your overall health. Find ways to reduce stress, whether that’s meditation, going for a walk, yoga, spending time in sunshine ☀️.
- Keep your blood sugar balanced by frequently eating balanced meals and snacks that include protein, fat, and carbs. Make sure to eat a hormone-friendly breakfast and never eat carbs alone.
- Get enough quality sleep.
- Get enough bioavailable protein from animal foods (at least 100 grams/day for women).
- Don’t overdo the cardio or endurance training which can cause excessive stress on the body and suppress thyroid function.
Questions about thyroid function and metabolism? Let me know!
I am not a doctor, and I don’t claim to be one. I can’t prevent, treat, cure or diagnose illness or disease. The information presented on this website is not meant to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice, treatment or diagnosis. The purpose of this website is to share knowledge from my research and experience. I encourage you to make your own decisions regarding your health care based on your own research and relationship with your health care professional.
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