Americans are living longer and healthier than ever before. For example, during the decade from 1980 to 1990, life expectancy in the United States increased nearly two years from 73.7 years to 75.4. Fortunately, during most of our lives we live in a healthy state. However, these improvements in longevity and health are largely due to medical advances, rather than lifestyles changes.
Our society, which places such emphasis on thinness and physical appearance, has been getting heavier. Recent studies have shown that during the same past decade, the prevalence of obesity has risen from 26% to 34%.
There is so much discussion in magazines, newspapers, and television talk shows on obesity and its treatment that Americans are becoming hung up over what they should do. Everyone wants to look good in bathing suits, to wear sexy clothes, and to fit into a suit worn ten years ago, as if thinness will suddenly change one's life!
Many Americans have become desperate and have turned to various commercial weight loss programs, many of which have been forced to close or to change their advertisements because of unsubstantiated claims of success. Some people will rush to try any treatment that sounds simple and easy, though it makes no sense, has little or no chance of working, and is potentially dangerous. We are all part of the society that stresses the taking of a pill or seeking a quick fix to instantly cure a problem that has take so many years to develop.
So it is not surprising that some desperate people, and their equally desperate physicians, will try thyroid hormone in an effort to lose weight. After all, we all know that "thyroid hormone controls metabolism" and that "metabolism controls weight," so why shouldn't thyroid hormone be an ideal diet pill? Moreover, many people still respond to questions about their family history of thyroid disease by stating that their aunt or sister "must have had a thyroid problem because she was so fat." In addition, anyone who has had Graves' disease and who lost weight during the hyperthyroid phase is usually quite happy with that symptom, but very upset with the regaining of the weight that occurs once the elevated thyroid hormone levels are brought down to normal.
Years ago, diet doctors were common. Parents would take themselves or their chubby children to these doctors, many of whom had no formal training in the treatment of obesity, or in endocrinology. Often these doctors were physicians who tried whatever fad was popular, from pills to shots to cookies to liquid protein to starvation, without a true understanding of obesity and eating behavior.
Once-popular forms of diet pills were called rainbow pills, which contained "a little digoxin, a little amphetamine, a little diuretic, and a little thyroid"- all in different color capsules and only obtainable from the diet doctor's office. It has taken a long time and even some medical malpractice cases for these doctors to close down their offices. Yet even today, some patients will still ask for these types of pills, even for a short time, just to get a jump start.
Thyroid hormone and its role in metabolism are poorly understood, even by basic scientists and thyroid specialists. Certainly, thyroid hormone controls the synthesis of certain proteins in the body's cells. During times of acute or chronic illness there are changes in thyroid hormone concentrations, perhaps to save the body from using up is own energy stores. Certainly, some patients with documented hypothyroidism will have gained five to ten pounds that will shed after becoming euthyroid. Short of that, there are NO studies showing any positive effects for long-term weight control for individuals who have normal thyroid function and who take excess amounts of thyroid hormone.
It is not for lack of trying! Both thyroxine (T4) and the more potent triiodothyronine (T3 ) have been tried, both at normal replacement dosages and at much higher dosages. Some people will lose a few pounds, but the weight loss comes from breaking down muscle mass, NOT the fat they desperately want to lose.
Although some very obese people can tolerate very large amounts of thyroid hormone without adverse effects, most people will soon become clinically and biochemically hyperthyroid. Older persons are highly susceptible to the side effects of excess thyroid hormones, especially T3. Symptoms might include extreme nervousness, restlessness, insomnia, palpitations, tremors, headaches, and problems concentrating. This state of excess thyroid hormone may also cause the loss of calcium from the bones, especially in postmenopausal women.
Clearly, thyroid hormone has NO role to play in the treatment of obesity. It should be used only for the treatment of documented hypothyroidism, suppression of enlarged thyroid glands or nodules, and in thyroid cancer.
The treatment of obesity requires much more than a magic bullet approach, including a better understanding of: possible metabolic defects, psychological stress, resistance to exercise, and triggers to normal hunger and binge eating.
For now, at least, sustained weight loss can only be attained with comprehensive life style changes. It is also important to have realistic expectations of what can be achieved. Attempting to use thyroid hormone for weight loss is not a quick fix - if anything, it is potentially dangerous.