Weight Gain

Obesity, weight gain and weight management is about more than calories taken in and energy expenditure out. The balance of our hormones forms the energetic template and structure around which our body rebuilds itself. The purpose of this article is to give you a beginning perspective on how our hormones form this template around which our body structures its metabolism and form.

The main hormonal players in the obesity game are:

  • thyroid hormone: T3 aka triiodothyronine
  • growth hormone
  • sex hormones: estrogen/testosterone
  • adrenal hormone: cortisol
  • leptin
  • gherlin

Thyroid Hormome:

The active hormone of the thyroid is T3 called triiodothyronine. The pituitary excretes thyroid stimulating hormone (TSH) which stimulates the thyroid to make T3 from thyroxine (T4). Traditionally doctors would take a blood test for your TSH, T4 and T3 levels. If  TSH was elevated, then it indicated the body’s attempt to stimulate the thyroid to make more T3.

It has only been in the last year that free T3 levels are now being tested routinely by astute doctors and heal care providers. What is free T3? It is T3 that is not bound by anti-bodies. It has been discovered that individuals with autoimmune inflammatory conditions such as:

  • chronic fatigue
  • Hashimoto’s thyroiditis
  • allergies
  • arthritic conditions
  • environmental sensitivities
  • food sensitivities
  • irritable bowel

and other immune driven conditions will develop an immune sensitivity to their own thyroid hormone. Many times this is a temporary condition that resolves once the underlying immune sensitivities are brought under control and resolved. However, sometimes they become a full blown auto-immune attack against the thyroid gland itself and not just against the thyroid hormone. These individuals will go on to develop Hashimoto’s thyroiditis or Wilson’s syndrome.  Therefore, adding free T3 to one’s blood test helps the medical practitioner to determine how much T3 is available for you to use as you can only use T3 that is unbound (unattached to an antibody). With the addition of testing for free T3 one can now find effective low thyroid hormone levels when total T3 looks normal!

Why is thyroid hormone implicated in obesity and weight gain?

T3 controls your body’s energy metabolism called your basal metabolic rate. It controls your rate of protein synthesis which has a direct impact on your body’s ability to maintain your muscle mass. It also plays a crucial role in your sugar metabolism by controlling the rate in which glycogen is broken down into glucose and it boosts the effect of insulin. Without this useful hormone you are more likely to become insulin resistant and develop Syndrome X, from it. T3 also directly affects your heart, controlling its force and rate of contraction and your oxygenation as a result. It’s hard to feel like moving your body when you heart is feeling sluggish!

Groth Hormone:

Human growth hormone (HGH) is considered a master hormone because it affects all areas of our body. When we are young, in our early 20’s we have the highest level of growth hormone and as a result we look pretty good! By the time we reach our 40’s our levels of HGH have declined significantly. Research has observed that along with the steady decline in growth hormone we see a steady loss of muscle mass, decreased in energy as a result and increase fat mass. Stimulating the pituitary gland in the brain to synthesize  HGH causes an increase in muscle mass back to one’s prime age and loss of fat mass. Studies are confirming that individuals suffering from obesity have lower than normal HGH levels.

The metabolic effects of HGH involve protein, fat and sugar metabolism. HGH increases the uptake of amino acids by the body helping it to build muscle. It also enhances the usage of fat, stimulating the breakdown of triglycerides. Therefore, it helps us have better cholesterol levels and fat metabolism. HGH is also crucial in sugar metabolism because it boosts the liver’s ability of the liver to make glucose. However, a side effect of injectable HGH is secretion of excessive insulin and the development of insulin resistance! There is a huge difference between taking supplements to stimulate the synthesis of HGH and taking HGH directly (which is known to cause side effects of hypertension, joint pains, insulin resistance and heart problems).

Sex Hormones And Obisity:

For women the onset of menopause results in perplexing weight gain. Research has discovered that the loss of estrogen receptors (ER-alpha receptors) in the brain, in particular your hypothalamus caused a chain reaction of metabolic effects that result in increased appetite, increased insulin resistance and increase abdominal fat! These receptors control hunger, thirst and temperature! Loss of these receptors in rats resulted in increased insulin resistance and immediate weight gain, especially belly fat and increased appetite! (American Chemical Society 2007, August 20, Revealing Estrogen’s Secret Role in Obesity.)

Men approaching middle age can also become hormonally imbalanced and their testosterone synthesis can divert to a higher level of estrogen synthesis. Its effect is to increase fat retention especially in the breasts of men.

With increases in fat retention, fat cells store estrogen! This makes the problem worse because it isn’t the level of estrogen that keeps us slim but our usage of it. Too much stored estrogen in tissues makes our body resistant to using estrogen and we become “estrogen dominant”, and store estrogen. This increases fat storage and our risk for estrogen dominant cancers in both men and women. When estrogen is able to enter our cells (because the cells are not resistant to absorbing estrogen) it helps to control appetite. (Yale University, Jan. 4, 2007, Estrogen Curbs Appetite in Same Way as the Hormone Leptin.)

Obese men have lower testosterone levels and obese girls and women have higher testosterone levels. Testosterone is necessary to maintain muscle mass. It has not been conclusively determined to date whether this apparent imbalance of testosterone in obese individuals comes from the gradual onset of obesity or whether the imbalance of the hormone itself induces metabolic imbalances that fuels obesity. Like estrogen, both factors are probably true.

Excessive Cortisol:

Cortisol is produced by our adrenal glands located above our kidneys. When we are under stress or while we are fighting off infection, our body increases our cortisol to stimulate the body to ramp up its sugar metabolism and immune action. The problem arises when stress or infection becomes chronic and the body becomes resistant to the stimulating effects of cortisol. Insulin resistance and immune fatigue will result, stimulating fat storage, especially belly fat.


Leptin is a relatively newly discovered hormone, in 1994. This hormone is found in direct proportion to the level of body fat we have. This mean the fatter we get the more leptin we make. It is made in white fat, brown fat, breast tissue, bone marrow, the pituitary, the liver, ovaries, muscles and the stomach.

So called ‘normal’ levels of leptin help our body to control our appetite by acting on our brain, in particular the hypothalamus to inhibit our appetite. Compounding the excessive production of leptin by the above tissues is the fact that the very act of eating food stimulates our body to make more leptin. Add this fact to the fact that as we gain more fat cells, the secretion of leptin increases and we develop resistance to any excessive hormone secretion, including leptin. Leptin resistance causes us to have increased appetite because the hormone becomes ineffective!


Ghrelin is a hormone secreted by the empty stomach. Its function is to stimulate hunger. If we skip a meal, especially breakfast we end up making more ghrelin overall. The result is that when we do eat the synthesis of ghrelin declines but our overall level of ghrelin is higher contributing to night time hunger!

Another function of ghrelin is to increase the volume of food we want to eat and to increase out fat mass! As you can see, if you wait too long to eat and get too hungry, you will make more ghrelin and then you will overeat. The food you do eat will then be stimulated to fat storage because of this hormone. Balance is everything, so don’t ignore hunger and don’t skip breakfast!


Dopamine is a brain chemical, a neurotransmitter that is linked to our ability to maintain focus, and produce feelings of satisfaction and pleasure. It also plays a part in our body’s metabolism. Studies have found a link between low dopamine receptors in the brain and obesity. With increases in obesity (increases in BMI) they found fewer dopamine receptors! Fewer receptors mean that you are more likely to eat more to try to stimulate the dopamine “pleasure” circuits and can become addicted to food just like drugs and other compulsive behaviors. What has not been determined is whether the reduction in dopamine receptors is a cause or consequence of obesity.

Drugs that increase dopamine receptor sensitivity are highly addictive and become less effective over time. What has been shown to increase dopamine receptor sensitivity and release is exercise! (Brookhaven National Laboratory Feb.6, 2001, Scientist Find Link Between Dopamine and Obesity)

With all the above hormones, there are complex regulatory mechanisms that cause each hormone to interact not just with our brain but with other tissues in our body and other hormones. Correcting imbalances is a complex picture that involves balancing all one’s hormones with proper lifestyle, stress reduction, supplementation and diet.

Please note:
Information on this site is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this site for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment.

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Anna Manayan

Anna Manayan