Hypothyroidism is the condition that happens when your thyroid doesn't create and release enough thyroid hormone into your body. When there isn't enough thyroid hormone in your bloodstream, your metabolism slows down, affecting virtually every system in the body.
For decades, the topic of metabolism has been synonymous with weight loss. However, it's much more comprehensive. Metabolism is a vital bodily function, without which your body would cease to function.
Metabolism refers to the chemical processes responsible for maintaining essential functions like breathing, cell building, and digestion. The calories in our food provide the energy required for these chemical reactions. Your metabolic rate is the number of calories you need each day to maintain these essential body functions.
The difference between slow and fast metabolism is how many calories you burn to support these essential functions. A slow metabolism burns fewer calories than a fast metabolism. Things like gender, body composition, age, daily activity, and genetics determine your metabolic rate.
Connection between hypothyroidism and metabolism
The thyroid is not the only component involved in regulating metabolism. Still, a properly functioning thyroid helps your body maintain the level of thyroid hormones it needs to keep a satisfactory metabolic rate. When your thyroid doesn't produce enough thyroid hormones, your metabolism and body processes slow down and change.
Common symptoms of hypothyroidism include:
- Puffy face
- Muscle weakness
- Elevated blood cholesterol level
- Muscle aches, tenderness and stiffness
- Joint pain, stiffness or swelling
- Heavier than normal or irregular menstrual periods
- Slowed heart rate
- Impaired memory
- Enlarged thyroid gland (goiter)
In addition to the thyroid gland, the pancreas also helps to control metabolism. The pancreas secretes hormones—insulin and glucagon—that determine whether the body's main metabolic activity at any one time and anabolic (building and maintaining your muscle mass) or catabolic (breaking down or losing overall mass, both fat and muscle).
How to maintain a healthy metabolic rate
Your metabolic rate comprises the basal metabolic rate (BMR), thermic effect of food, and your physical activity level. Your BMR is the number of calories required to keep your body functioning at rest. The thermic effect of food is the energy needed for digestion, absorption, and disposal.
You may see food marketed to speed up your metabolism. While some foods like coffee, chili, or spicy foods may minimally increase your metabolic rate, this is not permanent nor substantial. Instead, there are foods you can avoid or eat less frequently to maintain a healthy metabolism. Avoid fried foods, fatty foods, or foods with refined sugars. While these foods are tasty or tempting, they do not require much energy to metabolize, resulting in fewer calories burned, allowing your metabolism to slow down. Your metabolism works harder to break down protein and complex foods like whole grains. Therefore, you expend more energy and burn more calories.
Don't crash diet
Just as what you eat can affect your metabolism, the same goes for what you don't eat. Withholding food from your body or crash dieting can negatively affect your metabolism. Contrary to some diet claims, not eating for long periods can slow your metabolism. If you don't eat from morning until night your body goes into emergency mode, thinking there must be a shortage of food. This results in your metabolism slowing down to try and make the most use out of each calorie. Your body will burn fewer calories and use less energy, possibly leading to weight gain, fatigue, and irritability.
How you exercise affects your metabolism. Building muscle and strength can increase your resting metabolism as muscle is more metabolically active than fat. Something like high-intensity interval training may not be the most appealing to those with low energy or fatigue with hypothyroidism. Instead, lifting heavy weight with low repetitions can help increase your metabolism and burn more calories each day—even at rest.
Aerobic exercise is the most effective way to burn calories. It's best if you aimed to do at least 30 minutes of aerobic activity—like walking, cycling, or swimming—three to five times per week. To lose weight, you may need to do more than this and make nutrition and lifestyle modifications.
Get quality sleep
Just as food deprivation can negatively impact your metabolism, so does sleep deprivation. There is growing research that low quality or too little sleep can decrease leptin levels and increase ghrelin levels, two of the hormones involved in regulating metabolism. Leptin decreases hunger, and ghrelin increases hunger.
Take a thyroid blood test to understand how your thyroid is functioning and if it may be impacting your metabolism. Many labs only look at thyroid-stimulating hormone (TSH), but it’s critical to also measure fT3, fT4, and TPO antibodies to understand the full picture. Should your results show that your thyroid is underactive, it is easily treatable in almost everyone. Optimizing your thyroid levels with medication is usually the first step in minimizing symptoms. When choosing thyroid medication with your doctor, remember that there is no one-size-fits-all treatment.
Get checked for other medical conditions
A metabolic disorder is when the metabolism process dysfunctions and causes the body to have too much or too little of what it needs to stay healthy. Metabolic disorders may include a missing enzyme, abnormal chemical reactions, a disease in the liver, pancreas, endocrine glands, or other organs, or nutritional deficiencies. Metabolic disorders are very complex and rare. If you have a metabolic disorder or are concerned that you have a metabolic disorder, talk to your doctor to determine the accurate diagnosis and treatment.
A note from Paloma Health
An optimally functioning metabolism provides your body with the energy to keep working even while you sleep—repairing cells, circulating blood, and breathing. To set a health plan that best supports your metabolism, consider meeting with a thyroid nutritionist.