Weight gain typically occurs from a combination of interacting physical, emotional / psychological, and sometimes "energetic" factors. The vast majority of these factors exert their effects on weight gain or loss through their stimulation or inhibition of certain hormones.
First, what is a hormone? A hormone is often described as a "chemical messenger". A hormone is a chemical released by a gland that is typically released into the bloodstream to tell certain cells and tissues to take some action that the body needs to have performed. The release of hormones is controlled by the central nervous system (specifically the brain), as well as by feedback systems that are triggered by certain sensors in the body that monitor the hormone levels in the blood, or monitor the effects of the hormones.
Under normal circumstances, diet, exercise, sleep, stress levels, and exposure to certain chemicals will determine hormone levels and function and the function of certain hormones in turn determines whether the body burns sugar, burns fat, breaks down muscle, or stores sugar, stores fat, or builds muscle. There are three primary hormones that promote fat storage: insulin, cortisol, and estrogen. There are six hormones that promote fat burning: thyroid hormone, growth hormone, insulin-like growth factor, glucagon, testosterone, and adrenaline. Even though there are more fat-burning hormones, the fat storing hormones are stronger in their effects. First let's look at the fat storing hormones and what stimulates them.
Insulin is the strongest of the fat storing hormones. Insulin is released by the pancreas for the purpose of regulating blood sugar levels. When you eat a meal that is high in carbohydrates, the carbohydrates are digested and absorbed into the blood as glucose (blood sugar). When there is a large amount of blood sugar present, large amounts of insulin are released. So, here's the first clue on how to lose weight: if insulin is the strongest of the fat storing hormones and carbohydrates cause the release of insulin, what type of food should you limit your intake of if you want to get rid of fat? (Hint: It's carbs!) Insulin will first store excess sugar (more than what is necessary for immediate use by the brain and other tissues) as a compound called glycogen. Glycogen is stored in the liver and muscles and can be quickly converted to blood sugar for fuel when needed, such as during brief periods of heavy exertion. There is pretty limited space for glycogen storage, so if there's more blood sugar that needs to be stored, the remaining amount will be converted and stored as fat.
There are many fat cells in the body and each fat cell can enlarge over 100 times its original size to accommodate more fat (which is why it is quite possible to get fat again after liposuction), so there is a large potential for fat storage. Again, the primary factor that stimulates insulin release is consuming carbohydrates, particularly refined sugars and grains. Vegetables (here we are talking about fresh or frozen whole, raw vegetables without any added ingredients such as sugar) also contain a high percentage of carbohydrates, but they do not stimulate insulin release as strongly as refined sugars and grains. Fruits (fresh, whole fruits) tend to increase blood sugar somewhat more than vegetables, but usually not nearly as much as grains. This is because vegetables and fruits are high in fiber and nutrients like beta-carotene that slow the absorption of their carbohydrates into the bloodstream when you eat them. Whole grains, because of their fiber content, stimulate less insulin response than refined grains. Whole grains are a much more concentrated source of carbohydrates than most vegetables and fruits (fruits and vegetables have a much higher water content than whole grains) and it is easier to consume more grams of carbohydrate from grain sources than from vegetables and fruits, so even whole grains tend to be problematic for causing fat storage. As mentioned earlier, insulin is the strongest of the fat storing hormones. It is such a powerful stimulator of fat storage that it can literally shut off fat burning for 24 to 48 hours when it is released in large quantities. In fact, a single slice of white bread will be enough in most people to dramatically inhibit all fat burning for one to two days, regardless of how a person eats or exercises during that time period. This is why limiting carbohydrate consumption is critical to fat burning. This is not to say that you cannot lose weight if you are eating refined carbs, because you can definitely still lose water weight (which is usually necessary in an overall weight loss program), but it becomes very difficult to lose actual fat. Excess refined carbohydrate consumption with its accompanying insulin release is a key problem in the failure of many people's weight loss attempts. In fact, some diet plans actually recommend that people "cheat" or "reward" themselves with carbohydrates periodically in order to keep them motivated. That "reward" may seem like a good idea at the time, but it sabotages your progress and may contribute to frustration and eventual failure of the diet in the long run. Refined carbs need to be kept out of your diet if you are going to have sustainable weight loss. This point will be emphasized repeatedly as we go along.
Cortisol is another hormone that stimulates fat storage, primarily around the lower abdomen. Cortisol is released by the adrenal glands and its release is associated with stress. It is speculated that the storage of fat around the abdomen during times of stress served a survival purpose for our ancestors who had to live under harsh conditions, basically storing fat to be used for energy when physical demands were high and/or food supplies were low. Stress can take more than one form though, and these days emotional stress has largely replaced physical stress. This means we store fat in response to cortisol but we do not have the events present that would allow us to burn off the fat as were present in earlier periods of human existence. As just stated, stress can take more than one form, all of which can stimulate cortisol release and cause fat storage. Emotional stress, illness or injury, heavy physical exertion, relationship problems, major life changes, etc. can all cause excess cortisol release and its resulting weight gain.
It is interesting to note that excessive or excessively intense exercise can stimulate cortisol release, which means for people who are already overstressed and their adrenal glands have been overworked, too much or the wrong kind of exercise can actually promote weight gain! And if you think you can overcome that effect by going on a starvation diet along with the heavy exercise, think again! Not only does inadequate food intake stimulate even more cortisol release, your body will still not burn fat in the presence of high cortisol even though you're hardly eating anything. Instead, the high cortisol will cause your body will burn muscle tissue to convert to blood sugar. Although burning muscle will cause you to lose weight, you will actually be increasing your percentage of body fat, which again typically is deposited around the midsection. Furthermore, since muscle tissue has a high metabolic rate, the more of it you burn up, the slower your metabolism will get. If you've starved yourself and exercised like a maniac but still couldn't lose that roll of belly fat, now you know why. Later in the book, we'll discuss how to get off the cortisol "merry-go-round".
Estrogen is another fat-storing hormone. You might think this only applies to women, but men produce estrogen in small quantities and can be exposed to chemicals in food, water, and the environment that act like estrogen in the body. Estrogen is produced by the ovaries and adrenal glands. The adrenal glands are the source of natural estrogen in men and in post-menopausal women. As we mentioned a moment ago, there are outside sources of estrogen. One of the most common sources of what are called "exogenous" (not to be confused with "erogenous") estrogens is meats, particularly beef and pork, and dairy products. This is because commercially-raised cattle and hogs are often given extra estrogen to cause them to grow and fatten faster, and residuals of these hormones are in the meat and dairy products we consume. But meat is not the only source of estrogens in the diet. Various pesticides and chemical fertilizers used on produce can act as estrogens in the body. Because of the presence of these exogenous estrogens, it is recommended that you stick to naturally raised beef and pork, hormone-free dairy, and organically grown produce as much as possible. Estrogen tends to cause fat accumulation around the hips and buttocks and sometimes in and around the breasts (this is most noticeable when it occurs in men as a condition called gynecomastia - often referred to as "man-boobs"), presumably to provide close-by stores of energy for a developing fetus, and for breast milk production. But if you don't happen to be pregnant, this fat deposition is not normal and is due to an imbalance in hormones. Later, we'll discuss ways to balance estrogen levels through diet, exercise, and supplementation.
Before we discuss the fat burning hormones, there's something very important to know. ALL of the fat burning hormones are activated / produced by the liver. Under normal circumstances, the liver is quite good at handling all of the chemical reactions it must process, including the processing of fat burning hormones. Unfortunately, the usual American lifestyle can get pretty overwhelming for the liver. We tend to eat too much fat and protein and drink too much alcohol and take too many medications, and sometimes the liver just can't keep up. Since keeping levels of certain chemicals from reaching toxic levels in the blood is the liver's first priority, if you overload the liver, it's not going to be able to process the fat burning hormones as it should. This means that you will not produce adequate amounts of the activated forms of the fat burning hormones, and you will deposit fat. In addition, when the liver is overworked, fluid tends to accumulate in the upper abdominal area. The classic description of this is the "beer gut".
For people with overworked livers, a large amount of their excess weight is actually water. Some people try to exercise away the protruding gut through sit-ups or crunches in an effort to "spot reduce", but usually to no avail. Liver overload is also the primary reason many people don't get good long-term results with the Atkin's diet even though it often works great at first. The weight gain associated with an overworked liver must be addressed through changes in diet and by reducing the intake of alcohol and limiting the use of drugs and medications of all kinds as much as possible. As the liver recovers, the water weight will usually begin to recede pretty quickly (and you'll be spending quite a bit of time in the bathroom as it does!). The specifics for helping the liver recover will be covered later in this book.
Now we come to the fat burning hormones. Thyroid hormone is probably the most powerful of these - under normal circumstances of course. The thyroid gland produces an inactive hormone, called T4 which is converted to the active form T3 by the liver. The active T3 hormone stimulates cells to produce structures within them called mitochondria, which are kind of like energy factories that burn fat to convert to usable energy for a variety of functions. When thyroid hormone is either not produced adequately, not converted to the active form by the liver, or is blocked from its receptor sites on the cells (most commonly by excess estrogen or estrogen-like compounds), not only do the cells not burn fat, they also fail to produce sufficient energy for normal functioning. This obviously leads to weight gain, but also can cause fatigue, hair loss, and brittle nails. The weight gain related to thyroid issues is all over the body - trunk, arms, and legs, as the failure of fat burning is wide-spread. As just mentioned, some thyroid problems are due to blockage of the receptor sites for thyroid hormone, rather than due to insufficient hormone levels. This is why it is possible for someone to have classic low-thyroid symptoms even with perfectly normal blood tests for thyroid hormone levels. Thyroid hormone production is stimulated by exercise - primarily anaerobic exercise - and specific recommendations for exercise will be presented later. As we mentioned a short time ago, thyroid hormone is converted to the active form by the liver, so it is important that the liver be kept healthy - which basically comes down to not overloading it with excessive intake of fat, protein, alcohol, and/or drugs and medications. Finally, to keep the cellular receptor sites working normally, it is necessary to keep natural estrogen levels normal and to limit as much as possible one's exposure to exogenous estrogens by consuming natural meats and organic produce. Synthetic estrogens used in birth control and estrogen replacement therapy can also dramatically interfere with thyroid receptor sites and inhibit thyroid function, so you may wish to consider other options if you are using these medications and are having a lot of trouble losing weight.
Adrenaline (also called epinephrine) is a fat burning hormone that is produced by the adrenal glands. It accelerates the body's breathing and heart rate to provide more blood flow and oxygenation to the tissues in times of stress, or during heavy exercise. When you accelerate in a car, you burn more fuel, and the same is true when you accelerate the body - but in this case the fuel is fat and sugar. Many diet drugs either stimulate or simulate the action of adrenaline. The problem is that stress and diet drugs stimulate the adrenals generally, and also wind up stimulating the production of cortisol - the fat storing hormone we discussed earlier. Adrenaline is fast-acting, and produced in limited amounts, whereas cortisol is long-acting and can be produced over a longer period of time. So, while doing short bursts of intense exercise will give you the fat-burning effects of adrenaline, excessive exercise or excessive stress will stimulate cortisol release and hinder fat burning. Likewise, diet drugs will stimulate adrenaline production for a limited time, but the cortisol production they stimulate will last much longer - this is why many diet drug users wind up gaining weight in the long-run.
Growth hormone is produced by the pituitary gland in the brain. It stimulates the growth of muscle and lean body tissue. Muscle cells have a proportionately high number of mitochondria, the "energy factories" we discussed in relation to thyroid hormone. Because of this, more muscle tissue means more fat burning, so growth hormone indirectly stimulates fat burning. In addition, growth hormone stimulates the liver to produce a hormone called insulin-like growth factor (IGF). IGF controls blood sugar levels during long periods between eating - primarily at night when you are asleep. Without adequate sleep (at least 7 hours of RESTFUL) sleep per night, IGF does not function properly. A few hours after eating, your blood sugar begins to fall, and IGF stimulates the burning of stored sugar and fat to keep normal energy supply to the brain. So growth hormone has a second indirect effect on fat burning. Growth hormone (and consequently IGF) is stimulated by anaerobic exercise - which is of relatively short duration but high intensity. I'll discuss this in more detail when we get to exercise recommendations. I feel it bears mentioning that growth hormone injections are sometimes used to enhance muscle growth and reduce fat. This may be done illegally by athletes trying to artificially enhance muscle growth, or it may be prescribed by some doctors as an "anti-aging" measure for their patients. While growth hormone definitely has its good points, I urge anyone who is considering growth hormone injections to be very careful. Excess amounts of any hormone can be extremely dangerous, and injecting large amounts of growth hormone could potentially have serious adverse health effects.
Glucagon is a hormone that can be thought of as the anti-insulin. Like IGF, glucagon stimulates the burning of stored sugar and fat when blood sugar drops too low, but it operates much closer to the time when you eat. It is a counter-balance for insulin. Basically, when you eat and your blood sugar rises, insulin is produced to store the excess, but if insulin takes too much sugar out of the bloodstream, glucagon is released to bring the blood sugar back up again by burning the stored sugar and fat. Glucagon production tends to be stimulated by meals that are relatively low in carbohydrate.
The last major fat-burning hormone is testosterone. Just as men produce some of the "female" hormone, estrogen, women produce some of the "male" hormone, testosterone. Testosterone is produced by the testicles (in men) and the adrenal glands (in men and women). Like growth hormone, testosterone stimulates fat burning indirectly by stimulating muscle growth. Also like growth hormone, testosterone production is stimulated by anaerobic exercise - short duration, high intensity. And again, like growth hormone, injecting testosterone is potentially dangerous, so think carefully about artificially raising your testosterone levels.
So, now that we've reviewed the action of the various fat storing and fat burning hormones, let's summarize what causes fat storage and fat burning.
Fat storing is largely stimulated by:
1) Excess carbohydrate consumption
2) Excess stress (physical and/or emotional)
3) Excess estrogen and estrogen-like chemicals (such as chemical pesticides, fertilizers, etc.)
Fat burning is stimulated by:
1) Good liver function (avoiding the overconsumption of fat, protein, alcohol, and drugs/medications
2) Low carbohydrate consumption
3) Anaerobic exercise (relatively short duration, high intensity activity)
4) Adequate sleep (at least 7 hours of restful sleep per night)
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