The rate of obesity and overweight among people has tripled in the last four decades, and the statistics of weight loss surgeries have also multiplied for this reason. One of the reasons for being overweight can be thyroid surgery; Many people suffer from overweight and obesity after thyroid surgery. But what could be the reason? After thyroid surgery in people with an overactive thyroid, the thyroid hormone in the person's blood circulation is reduced, which makes the person in question unable to take in enough calories. In this article, we will discuss in detail
** thyroid function and its effect on obesity** .
Quick access
- Thyroid and overweight
- The relationship between BMR and overweight
- What effect will overactive thyroid have on people's weight? - Does thyroid function directly cause obesity? - How much weight changes will we have after thyroid treatment? - Thyroid hormones and weight loss
- The relationship between thyroid cancer and obesity
- Conclusion
Thyroid and overweight
There is a proven and complex relationship between thyroid hormone, body weight and metabolism. Thyroid hormone regulates the metabolism of human and animal bodies. The method of determining metabolism is to measure the amount of oxygen in the body in a certain period of time. If the resting metabolic rate is determined, it is called the basal metabolic rate (BMR), which is one of the first tests to evaluate the patient's condition. In the BMR test, people with overactive thyroid glands had high BMR rates and people with underactive thyroid glands had low BMR rates. In the later stages of the experiment, it was observed that low levels of thyroid hormone were associated with low BMR and high levels of thyroid hormone were also associated with BMR. Today, due to the high complexity of this test and the correlation of BMR with other cases, it is not used. Overactive thyroid and its effect on overweight
The relationship between BMR and overweight
Changes in thyroid hormone levels that lead to changes in BMR should cause changes in energy balance and similar changes in body weight.
Because many factors are involved in this. For example, when the metabolic rate is reduced in animals, the expected weight gain often does not occur. Therefore, the relationship between metabolic rate, energy balance and weight changes is very complex and cannot be easily analyzed. Many other hormones (except thyroid hormone) contain proteins and other chemicals that are very important factors in controlling energy expenditure, food intake, and body weight. Because all of these substances interact with parts of the brain and body that control energy expenditure and energy intake, we cannot attribute weight change caused by just one of these factors to body weight. As a result, at present we cannot generally prove the direct effect of thyroid on overweight or the issue of thyroid function and its effect on obesity.
What effect will an overactive thyroid have on people's weight?
Because BMR is high in patients with hyperthyroidism, many patients with hyperthyroidism experience some weight loss. For example, if the thyroid is overactive, a person's BMR will increase, leading to an increase in calories needed to maintain body weight. If a person does not increase their calorie intake to match the extra calories they burn, they will lose weight. As mentioned earlier, the factors that control our appetite, metabolism, and activity are very complex, and thyroid hormone is only one factor in this complex system. Nevertheless, in general, it can be said that the more severe the hyperthyroidism, the more weight loss is observed.
Since hyperthyroidism also causes an increase in appetite, some patients may not lose weight and some may gain weight due to the increase in their calorie intake. So, we can draw the general conclusion about thyroid function and its effect on obesity that the reduction of thyroid hormone causes a decrease in metabolism and, as a result, weight gain.
Does thyroid function directly cause obesity?
If people with hypothyroidism are treated with replacement hormones, there will be no difference in weight change compared to people without thyroid problems. Therefore, we can say that thyroid function is not the main cause of weight change and does not have a direct effect on overweight. Thyroid function and its effect on obesity can be seen as a matter based on the reduction of metabolism and the accumulation of water and salt in the body. Therefore, obesity after thyroid surgery is not caused by the accumulation of fat in the body, and excessive weight gain is rarely seen in people with hypothyroidism. Depending on the severity of the hypothyroidism, 5 to 10 pounds of body weight may be related to the thyroid; But obesity cannot be considered solely caused by thyroid hormone changes.
How much weight changes will we have after thyroid treatment?
Most of the weight gain in hypothyroidism is due to the accumulation of salt and water. When hypothyroidism is treated, we can expect some weight loss (usually less than 10 percent of body weight). But as mentioned earlier, if the symptoms of thyroid function other than weight gain are resolved with thyroid hormone treatment, it is unlikely that the weight gain is solely due to the thyroid. Once hypothyroidism is treated and thyroid hormone levels are within normal range, patients will have the same weight changes as other people who do not have this disease.
In the past, thyroid hormones were used as a tool for weight loss; In such a way that by increasing the level of thyroid hormones, they reduced the weight. The effect of weight loss with excessive increase in thyroid hormone is greater than dieting, but it will have negative consequences such as loss of muscle protein, bone loss, or heart problems. Furthermore, once the increase in thyroid hormones stops, the weight returns to normal.
The relationship between thyroid cancer and obesity
Experts have confirmed that the risk of thyroid cancer and overweight are related. In a study conducted by Kitahara and his team among 830,000 men and 1,200,000 women, body mass index and waist circumference were measured, and their analysis showed that the higher the BMI in adulthood, the higher the risk of developing thyroid cancer and dying from it. Kitahara believes that if a person has low thyroid function, their TSH (thyroid stimulating hormone) is high and thyroid hormones known as T3 and T4 are low, leading to weight gain.
Conclusion
Many factors besides thyroid are involved in overweight; Therefore, the thyroid cannot be considered the only reason for overweight. Regarding thyroid function and its effect on obesity, it can also be said that by reducing thyroid hormones in order to treat thyroid problems, metabolism decreases and as a result, weight increases. In this article, we discussed the effect of many factors that are effective in overweight people; We hope that this information is useful for you and that we have given you the necessary knowledge about how to gain weight due to thyroid problems.
Dr. Abdul Hosseini
Surgeon and advanced laparoscopic surgery fellowship, bariatric and metabolic surgery, metabolic surgery for the treatment of type 2 diabetes