The onset of andropause in men is associated with a decrease in testosterone levels. Testosterone helps maintain strong and healthy bones and muscles, and low testosterone has been linked to increased amounts of fat in the body. According to Dr. Malcolm Carruthers in The Testosterone Revolution, “weight gain which doesn’t respond to diet is one of the most common and demoralizing effects of this condition.”
Dr. Carruthers explains that a spreading waistline may be attributed in part to the body’s increased resistance to the action of testosterone and because more testosterone is converted to estrogen. Testosterone deficiency is also responsible for more sugar and protein from food to be converted to fat, so the natural tendency is to gain weight. Testosterone therapy may, therefore, help to improve sugar metabolism by directing more to the rebuilding of muscles, rather than to the conversion to fat.
On the other hand, a hormonal condition called polycystic ovary syndrome (PCOS) that affects millions of women results in an overabundance of certain hormones including testosterone. One of the most common symptoms of PCOS is weight gain, so in these cases, an excess of testosterone may be a culprit.
One of the most common complaints voiced by women as they experience menopause is that they gain unwanted weight. While this is certainly not the case for everyone— and it can happen before, during, or after menopause— weight gain is frequently associated with the changes in hormone levels that occur during menopause. Declining estrogen levels may be only one factor involved; others include heredity, diet, physical activity, and weight distribution.
However, fat distribution has been shown to change as a result of decreasing estrogens. In particular, as estradiol production declines and estrone levels rise during and after menopause, women tend to show excess fat in a pattern similar to that seen in men—it appears around the belly (often described as “apple-shaped”).
As a woman’s ovaries naturally produce less estrogen during perimenopause, fat cells in the body respond by producing more estrogen. This is the body’s way of striving to maintain hormonal balance, but it can result in an increase not only in the number of fat cells, but their size as well. Estrogen is capable of stimulating the enzymes in fat cells and directing where fat is stored. Often it is sent right to the waistline.
The interaction between estrogens and fat cells may help to explain why menopause and its associated drop in estrogen production are often a time of weight gain, or fat redistribution. While estrogen therapy does not necessarily help women lose weight, it may help shift fat back to the chest and hips, rather than the stomach.
Dr. Isaacs explains that “what estrogen can do is improve vitality and insulin resistance, two key factors in battling the bulge.” He also states that studies confirm that women who take estrogen have more muscle and less fat than those who do not.
The thyroid gland and the hormones it produces may have a wide-ranging impact on our weight because the thyroid controls, among many other things, our metabolism. When the thyroid begins to malfunction and thyroid hormone levels decline, energy levels typically decrease, causing a feeling of sluggishness. This also makes you less motivated to exercise. These effects, coupled with a lowered metabolism, often lead to weight gain.
Dr. Mark Starr, in his book Type 2 Hypothyroidism, believes that there is a strong connection between the obesity epidemic in the U.S. and the growing incidence of type 2 hypothyroidism. He defines this as low thyroid function due to an insensitivity of tissues to thyroid hormones, which appear as normal levels in the blood.
Compounded with a low metabolic rate creating weight problems, type 2 hypothyroidism often causes tissue accumulation of mucin (a gel-like substance normally found in the skin) and further contributes to the appearance of fat deposits.
Cortisol is a hormone that plays a role in the regulation of blood sugar levels and determines immune system response. A primary function of cortisol is to stimulate the conversion of protein to glucose; this is critical for maintaining appropriate levels of blood glucose for use throughout the body.
Fluctuating glucose levels may have a direct effect on signals sent to the brain regarding hunger and appetite. Cortisol production also stimulates the release of fatty acids in adipose (fat) tissue, but the long-term effect is often a gain in fat.
Cortisol is considered the body’s primary stress hormone as it provides responses to stresses of all types—and we all know how stress can influence appetite and eating. Chronic stress is known to cause sustained high levels of cortisol, and one of the many effects is an increase in appetite and cravings for certain foods. In his book The Cortisol Connection, Dr. Shawn Talbott says, “because one of the primary roles of cortisol is to encourage the body to refuel itself after responding to a stressor, an elevated cortisol level keeps your appetite ramped up—so that you feel hungry almost all the time.”
Another hormone that is believed to influence metabolism and weight control, although indirectly, is melatonin. This hormone is produced by the pineal gland, a small gland embedded deep in the brain that controls the body’s biological clock.
Around the age of 40, the production of melatonin by the pineal begins to slow down. Because melatonin has been shown to decrease cortisol levels in the body–and cortisol is produced in response to stress–melatonin may help regulate the sometimes harmful effects of cortisol.
With regard to metabolic control, melatonin has also been shown to enhance the production of T3, which is important in the regulation of healthy metabolism. That is why changes in melatonin levels can indirectly affect some of the body’s mechanisms that regulate metabolism, stress, and weight gain.
Human Growth Hormone
Recent studies have demonstrated that there is an inverse correlation between body fat and human growth hormone (HGH) production. In general, the more body fat you have, the less growth hormone you release; conversely, the less body fat you have, the more growth hormone you release. But why does this matter? According to Dr. Ronald Klatz, in his book Grow Young with HGH, for older people, trying to lose central fat from around the belly is very difficult. Adequate growth hormone may actually help in the battle against fat accumulation.
Studies also suggest that a decrease in growth hormone secretion in overweight individuals who carry their weight mostly around their belly is a sign that their hormonal system—especially the regulation of growth hormone and other related hormones— is not functioning properly. One such study showed that when this problem is treated by providing the body with growth hormone, other benefits such as better regulation of cholesterol levels, blood pressure, and glucose metabolism may occur.
Leptin, a very recently discovered hormone, is proving to be a significant player in the overall system of hormones and their relation to weight, body shape, appetite, and metabolism. Secreted by fat cells contained in white adipose (fat) tissue, leptin has been shown to be a master regulator of many other hormones, including the sex hormones and those produced by the thyroid and adrenal glands.
Leptin works by sending a signal to our brain to let it know how much fat is stored, analogous to a fuel gauge in a car telling us how much gas is in the tank. The information that leptin sends to our brain allows the brain to act accordingly and regulate energy for our entire body. When the signaling by leptin malfunctions, weight control may be affected in either of two ways. One problem can occur when fat cells producing leptin don’t produce enough, so leptin isn’t able to signal to the brain that the body is satiated.
Another problem is a condition called leptin resistance and occurs in overweight people when leptin is no longer efficient at sending information to the brain. When the brain does not detect the proper level of leptin, it is fooled into thinking that fat storage levels are low and responds by slowing down the metabolic rate in order to store more fat as fuel. This results in excess fat in the body.
Leptin resistance is also believed to be responsible, at least in part, to the weight gain that many women experience after menopause. As estrogen levels begin to decline, it creates a breakdown in communication between estrogens and leptin, creating an imbalance in the signals involving leptin, estrogen, testosterone, and insulin.
Human Chorionic Gonadotrophin (hCG)
Back in 1954, endocrinologist Dr. Albert T. Simeons theorized that there are three types of fat in the body: structural fat such as the padding on the feet and the cushions between organs; fat reserves, which are easily accessed for energy when the body needs it; and abnormal fat deposits, which cannot be accessed and are a hallmark of obesity.
In his book Pounds and Inches, Dr. Simeons describes his experience with using small doses of hCG, in combination with a very low-calorie diet, to mobilize the abnormal fat deposits as a treatment for obesity. While the use of hCG for weight control is somewhat controversial, it is not surprising that the action of hCG on the hypothalamus, found in the most primitive part of the brain, may have something to do with how we store and use our fuel.
Hormone Balance and Your Weight
As discussed here, many different hormones play a role in weight control and metabolism. A shift in hormone levels can affect the delicate balance needed to maintain a healthy weight. In addition, obvious factors such as food intake, exercise, and lifestyle (e.g., stress, smoking, and alcohol consumption) also affect your weight, both directly and indirectly, because hormone production and function are also influenced by these other factors.
With all the complexities involved with the metabolism and weight control, you may want to partner with your healthcare practitioner to determine the best approach for achieving a weight that is right for you.