Meet Your Metabolism Hormones
Before diving into this weight-loss plan, you need to know about the hormones that play essential roles in your metabolism. When these suckers are out of whack, they can do a real number on your body. So here's a rundown of the top 12 metabolic hormones — and how to make sure they're working for you, not against you.
Metabolic Hormones: The Major Players
In the past few decades, researchers have discovered dozens of hormones that have an effect on weight, but we'll be focusing on just 12 metabolic hormones here — let's call them the major players. When one or more of these hormones gets messed up, it creates metabolic disturbances that interfere with hunger, energy level, and body-fat and lean-muscle distribution, among other physiological effects. Some hormones are so closely related that I group them together in the descriptions below. The great thing is, once you know what's going on inside your body, you'll have the tools you need to master your metabolism and reach your weight-loss goals.
Player #1: Insulin
Player #2: Thyroid Hormones
Players #3 and #4: Estrogen and Progesterone
Players #5 and #6: Testosterone and DHEA
Players #7, #8, and #9: Norepinephrine, Epinephrine, and Cortisol
Player #10: Growth Hormone
Player #11: Leptin
Player #12: Ghrelin
Player #1: Insulin
This hormone affects nearly every cell in the body, so when it goes haywire it can really cause problems — I'm talking about potentially fatal health conditions. If you can get a handle on your insulin's ups and downs, you'll be on your way to restoring your body's hormone power.
Impact on your metabolism: The most important function of insulin is to lower the concentration of glucose in your blood. When you eat something, your body breaks down the food into simple sugars that are released into the bloodstream. Within minutes, the pancreas pumps out a series of insulin surges. Insulin then ushers the sugars directly into the liver, where they're converted into glycogen to fuel the muscles. Insulin also helps turn glucose into fatty acids and stores them in fat cells, where they can be tapped later as fuel.
While high levels of blood glucose trigger insulin release, low levels suppress it. Maintaining low levels of insulin — one of the primary goals of this diet — allows your body to more easily tap into your stored fat for fuel. When your insulin-release mechanism is working properly, it helps keep your weight in check. Otherwise, watch out!
How insulin gets messed up: Problems arise when your body starts creating too much insulin, which can happen for a number of reasons. The most common one is eating too many of the wrong carbohydrates (such as refined carbs like white bread and pasta) too often, which will cause your blood sugar to spike.
Here's an example: Let's say you have a Milky Way on an empty stomach. Your blood sugar soars to the point that insulin works twice as hard to clean it out of your blood, with the result that your blood sugar concentration drops, you feel hungry again, and you crave (and probably eat) more carbs. That's the "crash and binge" cycle, the root of sugar addiction.
When muscles are still fueled from your last snack, insulin puts any extra calories straight into fat cells. And as long as these large amounts of insulin are lurking in the bloodstream, your body won't have a chance to tap into your fat stores for fuel — so you won't burn any fat, either.
Player #2: Thyroid Hormones
Thyroid problems like hypothyroidism (a condition in which the body doesn't produce enough of this hormone) are very common in this country. Hey, even I was diagnosed with it! Thing is, most people with thyroid imbalances don't know it, because the symptoms — changes in energy, mood, and weight — are so similar to those of many other conditions.
Impact on your metabolism: Thyroid hormones perform a ton of functions. They help control the amount of oxygen each cell uses, the rate at which your body burns calories, your heart rate, overall growth, body temperature, fertility, digestion, and memory and mood. (Basically, the whole enchilada.) So when thyroid hormones are out of balance, either too high or too low, chemical reactions all over the body get thrown off.
How thyroid hormones get messed up: An underactive thyroid, or hypothyroidism, is often caused by Hashimoto’s thyroiditis, a hereditary condition in which the immune system attacks the thyroid. As it happens, women are royally screwed in this department — they're about seven times more likely to develop Hashimoto’s thyroiditis than are men. Hypothyroidism can make you feel sluggish and can cause you to pile on extra pounds that you can't blame on a poor diet or lack of exercise.
Given that hypothyroidism can make your metabolism slow down, you might think that hyperthyroidism would be a good thing, right? Wrong. Graves' disease, the most common type of overactive thyroid condition, can cause your heart to race, make you intolerant of warmer temperatures, and cause you to lose too much weight and feel run down.
With unpleasant effects produced at both ends of the thyroid function spectrum, you can see why it's important to get your thyroid tested and, if the results show an imbalance, to work with a good endocrinologist to get yourself back on track.
Players #3 and #4: Estrogen and Progesterone
Estrogen and progesterone are steroid hormones. Most people think of muscle-bound meatheads when they hear the word “steroid,” but all it means is that the hormones are created by your body from cholesterol. Men and women both produce these hormones normally, but a tremendous amount of estrogen is also found in our environment — the man-made estrogens used in hormone replacement therapy, pesticides, and food additives, and such plant-based varieties as soy and flaxseed.
In addition to directing a woman's entire development from child into adult, estrogen has a major impact on blood fats, digestive enzymes, water and salt balance, bone density, heart function, and memory.
Impact on your metabolism: Estradiol, one of the main forms of estrogen, helps women's bodies stay lean; it regulates hunger, stabilizes your mood, and keeps your energy levels high. It also lowers insulin and blood pressure levels, raises HDL ("good") cholesterol, and lowers LDL ("bad") cholesterol. Weight issues creep up as women approach menopause, when their production of estradiol decreases, prompting another type of estrogen, estrone, to play a larger role. Estrone causes the body to hang on to fat, especially in the belly.
Progesterone helps balance estrogen and can help manage some of the related effects, so a decrease in progesterone levels creates problems, too. Those mad junk-food cravings you get before your period? Blame a drop in progesterone.
As for men, estrogen levels that are out of sync with testosterone levels can affect their muscle-building, fat-burning advantage. Guys who develop female attributes like love handles and "man boobs" have an overabundance of estrogen to thank.
How estrogen and progesterone get messed up: It used to be thought that declining levels of estrogen were the root of women’s hormone balance problems. These days, too much estrogen seems to be to blame, and it’s causing problems for men as well. Why the rise in estrogen? Over the years we’ve increasingly been bombarded by synthetic estrogens, which are present in our cosmetics and cleansers, the preservatives in our processed foods, and the plastics in which we package and store our foods and drinks. Other factors to blame for the rise in estrogen include stress and a diet lacking in quality fats and protein in favor of refined grains, sugars, and processed foods. Some scientists believe that plummeting levels of progesterone in women during menopause also contribute to estrogen overload.
Players #5 and #6: Testosterone and DHEA
Although they’re called androgens and are usually thought of as male sex hormones, testosterone and dehydroepiandrosterone (DHEA) don't just benefit guys. These hormones can give women more energy, motivate us to hit the gym, and help us build more calorie-burning muscle. But don't worry, ladies — boosting these hormones won't turn you into knuckle-dragging Neanderthals.
Impact on your metabolism: Testosterone and DHEA are anabolic hormones — that is, they build rather than destroy. In other words, they are forces of good in the metabolic war. In both men and women, testosterone increases lean muscle mass and strength, boosts libido, and improves energy.
How testosterone and DHEA get messed up: Testosterone and DHEA are both hormones of youth. As we age, we produce less of these powerful androgens, and several things happen: Our libidos fade, our muscles lose mass, we gain abdominal fat, and our bones weaken.
Since high levels of testosterone and DHEA are a good thing, you’d want to take supplements, right? Wrong. When young men and women take artificial anabolic steroids to increase muscle mass, they actually train their glands to produce less of their own androgens. And taking a DHEA supplement without consulting an endocrinologist can hamper adrenal hormone production and cause your body to convert the excess DHEA into excess estrogen (which can cause weight gain and increase your chances of getting certain cancers). Bottom line: Don’t fool around with supplementation without medical assistance.
Players #7, #8, and #9: Norepinephrine, Epinephrine, and Cortisol
Often referred to as our fight-or-flight or stress hormones, norepinephrine, epinephrine, and cortisol can get us out of some pretty tight squeezes. They can help us meet an urgent deadline, save a kid from falling down a flight of stairs, and run to catch a bus. But while the effects of heart-pumping epinephrine and norepinephrine are fleeting, fat-storing cortisol's legacy lasts longer — and is not exactly helpful when you’re trying to lose weight and be healthy.
Impact on your metabolism: When you first become stressed, norepinephrine tells your body to stop producing insulin so you can have plenty of fast-acting blood glucose at the ready. Epinephrine relaxes your stomach muscles and decreases blood flow to the intestines (your body figures it's more important to you to save your life than to digest your food). Once the stressor has passed, cortisol tells the body to stop producing these hormones and to resume digestion.
If the stressor never goes away (and by definition, the chronic stress of a hellish job, overbooked schedule, or family problems never does), cortisol hangs around and continues to stimulate your appetite. I think you know where this is headed. You end up craving high-fat, high-carb foods. Once you eat, your body releases a cascade of rewarding brain chemicals that can set up an addictive relationship with food. You feel stressed; you eat. Your body releases natural opiates; you feel better.
When cortisol levels remain high, the body actually resists weight loss. Your body thinks times are hard and you might starve, so it greedily hoards any food you eat and fights to hang on to any fat already present. Cortisol also turns young fat cells into mature fat cells that hang on for dear life. To make matters worse, cortisol tends to create fat in your abdomen, and that fat has high concentrations of a specific enzyme that converts inactive cortisone to active cortisol. The result is a nasty vicious cycle.
How stress hormones get messed up: Chronic overstimulation of the adrenal glands, which produce the stress hormones, is epidemic in this country. Most Americans are both victims of and addicted to their stress — and their bodies pay the price. When you keep yourself in high-stress mode, you set yourself up for heart disease, diabetes, stroke, and other potentially fatal conditions.
So how can you lower your cortisol levels? Start by limiting your caffeine to 200 milligrams a day; avoiding simple carbs, processed foods, and refined grains; and getting plenty of high-quality protein. De-stressing techniques — deep breathing, meditation, and simply taking time out for yourself — are also absolutely essential. Whatever you do, don't take any over-the-counter "adrenal support" supplements — these can end up doing more harm than good.
Player #10: Growth Hormone
Growth hormone (also known as HGH, for “human growth hormone”) is something we all want more of. It builds muscle, burns fat, helps you resist heart disease, and protects your bones — among many other health benefits. People with higher levels of growth hormone tend to live longer, and better.
Impact on your metabolism: By increasing your muscle mass, growth hormone raises your resting metabolic rate and gives you more power for your workouts. It also helps you tap into your fat stores for fuel and discourages your fat cells from absorbing or holding on to any fat floating around in your bloodstream.
In addition to these amazing feats, growth hormone helps your liver synthesize glucose, and it promotes gluconeogenesis, a really cool process that allows your body to create carbs out of protein. This helps you lose fat faster while providing your brain and other tissues with the energy they need.
How growth hormone gets messed up: Growth hormone deficiency is a very real condition that’s especially detrimental in childhood. Kids without enough of the hormone end up shorter and experience delayed sexual development. Growth hormone starts to decline naturally sometime after our thirties, but certain bad habits can speed the decline.
Of all the things you can do to mess up your hormone balance, depriving yourself of good-quality sleep is probably the dumbest. The largest release of growth hormone happens during your deepest, stage 4, sleep. So if your sleep cycle is constantly interrupted, expect your growth hormone levels to drop.
Eating too many low-quality carbs and thus maintaining high levels of blood sugar and insulin is another way to suppress your growth hormone levels. Protein, on the other hand, can help release more growth hormone, so if you shortchange yourself there in favor of carbs, your production of the hormone will be doubly slammed. Evidence is also starting to emerge that hormones from pesticides and other contaminants in our environment and diet can affect our growth hormone levels.
You may have heard about HGH supplements, but whatever you do, don’t get HGH shots just yet. Supplementation is controversial and risky, and it may even cause insulin resistance. One surefire way to turn your body into a growth hormone factory is to get regular, intense exercise. Not only does this help you burn fat but it keeps your blood glucose levels stable so that you have the energy to keep on exercising. That means we all need to get off our butts and capitalize on this incredibly healthy way to slow aging — and not jab ourselves with HGH syringes!
Player #11: Leptin
Fat cells are more than blobs of yuck waiting to get bigger or smaller. The fat in your body is an enormous endocrine gland, actively producing and reacting to hormones. Researchers are identifying more and more fat-cell hormones every day, but perhaps the best studied is leptin.
Impact on your metabolism: When you've eaten a meal, the fat cells throughout your body release leptin. This hormone then travels to the brain's hypothalamus, where it switches off the production of neuropeptide Y, a substance that triggers your appetite and turns down your metabolic rate. Leptin also switches on other appetite-suppressing signals, so your body gets the message to stop being hungry and start burning more calories. When it's working right, leptin helps the body tap into longer-term fat stores, thereby reducing them. But when leptin signaling gets screwy, you may end up overeating, because you never feel that you've had enough food.
How leptin gets messed up: Believe it or not, low levels of leptin are not our biggest problem. Many people who are overweight actually have leptin levels that are too high. How could this be? Well, the more fat you have, the more leptin you produce. And as what happens with insulin resistance, when the body continually cranks out excess leptin — in response to overeating — the receptors for leptin can start to get worn out and no longer recognize it.
Leptin resistance and insulin resistance go hand in hand, but just as with insulin resistance, if you lose a bit of weight, your body will become more sensitive to leptin and start acting the way leptin it to intended — youll be able to push away from the table and say, "Enough!"
Player #12: Ghrelin
Leptin and ghrelin form a kind of yin-yang balance between hunger and satisfaction. Just as leptin tells the brain to turn off hunger, ghrelin tells your brain that you're famished.
Impact on your metabolism: Ghrelin is the reason you always feel hungry at particular moments in the day — your body's clock triggers its release according to a finely tuned schedule. Ghrelin is also released whenever your stomach is empty, and levels will stay up until you've given your body enough nutrients to satisfy its needs. (Because satiety signals can take some time to kick in, eating slowly can help you eat less overall.)
There are times when having high levels of ghrelin is a good thing. For example, your body requires ghrelin for you to move effectively through all the necessary phases of sleep. Without the proper progression, you won't get to stage 4, during which you get a big pulse of growth hormone — the muscle-building, fat-burning, disease-fighting wonder hormone. This is why I don’t want you eating after 9 p.m. — you want ghrelin levels to rise before bedtime.
For the rest of the day, though, the object is to keep ghrelin levels low. You don't need the diet-endangering hunger and the metabolic havoc the resulting sugar ups and downs wreak on your system.
How ghrelin gets messed up: Ghrelin is crafty about getting you to eat, so you have to stay ahead of these hormone surges. New research suggests that ghrelin triggers reward centers in the brain to make food look more appetizing, even when there's no reason to chow down.
One way to send ghrelin soaring is to eat too little. Constant calorie restriction keeps ghrelin levels high, which may be why some yo-yo dieters feel that their hunger gets worse the fewer calories they consume. It’s all part of nature’s way of getting us to eat. As we walk around in a world that's filled with way too much food, this ever-rising ghrelin is probably a big part of what makes maintaining weight loss so challenging.
Lucky for you, there are simple ways to manage your ghrelin levels — like eating a balanced meal every four hours and hitting the sheets for at least eight hours a night. That doesn't sound so bad, does it
-from jillianmichaels.com
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