What is Basal Metabolic Rate (BMR) and How is it Impacted by Hashimoto’s Thyroiditis?
We’ve all heard the word metabolism, and know it has something to do with our weight, most often in relation to being overweight and having a hear time losing weight. What exactly is your metabolism, and what is your Basal metabolic rate (BMR). Most importantly, how is your BMR affected by Hashimoto’s thyroiditis (HT), commonly referred to as a slow thyroid?
What is metabolism?
Metabolism is the group of chemical processes in the body essential to maintain life. But there are a lot of processes. Most of the time when we talk about metabolism, we are referring to how the body used the energy, measured in calories, that we take in through the food and drink we consume.
What is your Basal Metabolic Rate (BMR)?
The BMR, also referred to as resting metabolic rate, refers to the number of calories that it burns when it is at rest. The calories are burned in the process of breathing, digestion, maintaining an even core body temperature, and so on.
The BMR will ultimately effect whether you gain or lose weight, or maintain your current weight. It can be influenced in a number of ways. One key influencing factor is whether or not you have a slow thyroid. The medical name for this is hypothyroidism. One of the most common causes of hypothyroidism is Hashimoto’s thyroiditis (HT).
What is HT?
The thyroid is a gland in the neck that produces a number of important hormones which affect a wide range of bodily systems and functions. In particular, the thyroid hormones influence the key factors we just mentioned in relation to the BMR and what the burned calories are used for.
Sometimes the thyroid gland doesn’t function properly. It might not get the right signals from ‘upstream’, the hypothalamus and pituitary glands that control the release of thyroid hormones. Or, the person might not have enough iodine in the diet. Iodine is an essential nutrient for creating thyroid hormones.
But research has shown that in 90% of cases, the cause of a slow thyroid is HT. It is important to note that HT is not a failure of the thyroid gland. Rather, HT is an autoimmune disease.
In the case of HT, the immune system sees the thyroid as a threat and starts to kill off healthy thyroid tissue. Over time, this will mean fewer and fewer functioning thyroid cells. This will result in thyroid hormone deficiency, commonly referred to as a slow thyroid. Add to this the other factors that impact your BMR, and you can end up with a ‘perfect storm’ of weight gain and a poorer quality of life.
Other factors that affect your Basal Metabolic Rate (BMR)
There are a few other factors to pay attention to in relation to your BMR.
The more muscle you have, the higher your BMR. Muscle burns 3 to 5 times more calories than fat, so strength training can turn your body into a lean, mean, efficient calorie-burning machine. However, thyroid is key to muscle contractions, part of strength training, so HT can affect your ability to build muscle and maintain muscle mass.
The metabolic rate is highest during the periods of rapid growth, when you are young and can eat almost anything without gaining a pound. However, as you get older, you will start to lose muscle mass at the rate of 1 pound per year, thus slowing your metabolism. In addition, you are less active and burn fewer calories. More fat means less muscle.
Women have a metabolism 5% to 10% slower than men, and are 5 to 8 times more likely to develop HT.
If you think you have a slow thyroid, see your doctor for blood tests and work out a plan for boosting metabolism safely and naturally in order to get down to a normal, healthy weight.