Food and Mood: The Complete Guide to Eating Well and Feeling Your Best

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Food and Mood, Second Edition

I.

THE FOOD-MOOD LINK

CHAPTER ONE

How Food Affects Your Mood

What a miracle you are!

• With little or no effort, you can remember simple and complicated facts and events, so that by the time you have reached adulthood, you are a rich canvas of experiences, memories, and relationships.

• You can feel a wide array of emotions, from ecstasy and grief to boredom and apathy.

• You can solve problems, untangle puzzles, develop plans, and form opinions.

• You have a unique sense of humor and a one-of-a-kind personality, as well as personal dreams and hopes for the future.

• You are unique in the foods you love, the foods you hate, the foods you crave, and the foods you eat daily. Even how you decide what food satisfies a craving and how you go about soothing that need is peculiar just to you.

At the very foundation of each of these traits, talents, and preferences is an orchestra of cells and chemicals that allow your basic nature to develop and interact with the world. Who you are depends on how well that orchestra, called your nervous system, plays its music.

Getting to Know Your Neurons

The smallest functioning unit of the nervous system is the nerve cell, or neuron. This cell "talks" to other nerve cells and tissues by relaying electrical messages within the brain and back and forth through the nervous system to the rest of the body. To instinctively pull your hand away from a hot burner on the stove, blink an eye, feel hunger, decide what to eat, prepare a meal, hear a noise and recognize its origin, memorize a song, smell cinnamon and know it's coming from the bakery down the street, or perform any of the millions of thoughts, feelings, and actions you do every day requires that thousands of your 100 billion nerve cells and an equivalent number of support cells (called glia) communicate efficiently.

The neuron is not your typical cell. Most cells in the body are relatively spherical, but the nerve cell is shaped more like a tree. On one end are its branches, called dendrites, which allow the nerve cell to receive incoming messages from other neurons. These messages are relayed down the "trunk" of the nerve cell (called the axon), much like voice messages are carried on telephone wires. The axon can vary in length, from a fraction of a millimeter to three feet long (see Illustration 1.1). The messages eventually reach the "roots," or axon terminals, of the nerve cell, which bump against dendrites on other nerve cells. Nerve cells don't touch. Instead they are separated by tiny spaces that flow between the axon terminal of the sending nerve cell and the dendrites of the receiving nerve cell. This tiny space is called the synapse.

In order to relay the message from one nerve cell to the next, the sending nerve cell must find a way to "jump" the gap, or synapse, to get to the other side. Without some way to transmit messages across this gap, messages would stop at the end of the sending nerve cell, and all processes dependent on the nervous system, from moods to movements, would come to a halt.

To ensure this does not happen, nerve chemicals called neurotransmitters are stored in tiny sacs at the end of the axon terminals. The electrical message (such as a thought or a feeling message) traveling down the axon arrives at the terminal and causes some of these sacs to release their neurotransmitters. These nerve chemicals flow across the synapse, tickle the receiving nerve cell, and keep the message moving from one nerve to another, much like handing the baton to the next runner in a relay race. Once the neurotransmitter has relayed its message, it is broken down or reabsorbed back into the receiving nerve cell's storage space to be used again. In this way, neurons communicate with each other and send "state-of-the-union" messages from the body to the brain, and back again. The brain processes this information by sending messages back and forth among its billions of nerve cells and then releasing orders for action to the muscles and organs of the body—all within a split second and with no conscious effort on your part. Every dip or rise in mood, every hunger pang, every thought, every response—in short, who you are—is orchestrated by these nerve cells and their neurotransmitters.

A Symphony of Chemicals

Until recently, scientists had identified only a few chemicals and hormones that regulated body and brain processes, including insulin, adrenalin, noradrenaline, and glucagon. But in the past twenty-five years the chemical story has become considerably more complex with hundreds of newly identified compounds that regulate everything from your mood and what you want to eat to whether or not you experience headaches or develop heart disease.

The participants in this chemical symphony include neuropeptides such as neuropeptide Y (NPY) and galanin; amines; prostaglandins such as the prostacyclines and thromboxanes; the leukotrienes; and numerous hormones, from cholecystokinin (CCK), estrogen, and testosterone to cortisol, prolactin, and adrenocorticotropic hormone (ACTH). It is likely these and many other chemicals we've discovered recently are just the beginning and that many more compounds will be identified in the future.

At least seventy neurotransmitters have been identified that regulate nerve function, including memory, appetite, mental function, mood, movement, and the wake-sleep cycle. Table 1.1, "Some of the Chemicals That Influence When and What You Eat," on pages 9—11 provides a partial list of these neurotransmitters and other hormonelike compounds along with their effects on appetite. Disruption of even one neurotransmitter dramatically alters nerve cell function and instigates a cascade effect on other neurotransmitters, which can have profound effects on one or more of our physical, emotional, and mental processes. In essence, if an electrical message comes down the axon but there are insufficient amounts of the correct neurotransmitter at the terminal, then the message is not communicated to the next neuron, and the information flow stops. For example, too little of the neurotransmitter acetylcholine results in memory loss, while too little of the neurotransmitter norepinephrine causes depression. Too much of other neurotransmitters can overcommunicate a message. For example, excessive amounts of norepinephrine causes the mental disorder called mania.

To further complicate the symphony, these neurotransmitters are housed in central regions of the brain—such as the hypothalamus—that also regulate reproduction and communicate closely with other brain centers—such as the amygdala—that control emotions. Our food preferences, desires, cravings, and loves are literally hardwired into our basic instincts for survival, safety, and love!

What You Eat Affects How You Feel

What you eat directly and indirectly affects all these nerve chemicals, which in turn influence your moods, energy level, food cravings, stress levels, and sleep habits. For example:

1. Many neurotransmitters are composed of either amino acids—the building blocks of protein obtained from the diet—or a fatlike substance called choline, also obtained from food. When you consume too little of one or more of these dietary building blocks, your body limits production of the neurotransmitter dependent on their availability, and you experience changes in mood, appetite, and thinking. For example, the nerve chemical histamine is built from the amino acid histadine. Histamine is important in regulating alertness; brain energy metabolism; the release of hormones; appetite; and coordination.

2. Vitamins or minerals, such as the B vitamins, vitamin C, vitamin E, iron, selenium, and magnesium, are assembly-line workers in the manufacture of neurotransmitters; some aid neurotransmitter activity, as in the case of iron, and some protect neurotransmitters from damage, as in the case of vitamin E. If your diet does not supply ample amounts of these "helpers," neurotransmitters are not made or stored in sufficient amounts, and you feel grumpy or can't think straight. Correct these deficiencies, and mood and thinking improve.

3. Some neurotransmitters become more or less active depending on dietary intake. Either overconsuming or dramatically restricting a particular food, such as fats or carbohydrates, can trigger imbalances in neurotransmitters that can contribute to depression, irritability, food cravings, mood swings, and thinking problems (see Illustration 1.2, above).

4. Nutrients such as protein, zinc, vitamin B6, iodine, folic acid, and vitamin B12 are essential for the normal development of the nervous system. Insufficient intake of these nutrients from conception through the early years of life results in potentially irreversible damageto the nervous system, thus permanently altering personality, mental function, and behavior.

5. Some food additives, such as monosodium glutamate (MSG), and chemicals, such as tyramine (found in aged cheeses), can influence brain activity and result in mood changes, or can interfere with the manufacture or release of neurotransmitters. Other additives can block neurotransmitters so the receiving neuron is unable to understand the message. Still other additives alter the structure of a neurotransmitter, increase your cells' output of neurotransmitters, or affect the enzymes that normally regulate how much neurotransmitter remains in the gap between nerve cells. Any of these changes can have profound, yet sometimes subtle, effects on your mood and thinking.

The Diet-Made Chemicals: Serotonin, Dopamine, Norepinephrine, and Acetylcholine

The manufacture of most neurotransmitters is controlled by the brain. But some are directly influenced by what you eat, especially the amino acids (the building blocks for protein). For example, there are five neurotransmitters whose origins can be directly linked to the food we eat. Tryptophan, an amino acid found in meat and milk, is the building block for serotonin, and dopamine and norepinephrine are influenced by the amount of tyrosine in the diet. Histadine intake helps regulate production of histamine, and threonine is the building block for a nerve chemical called glycine. Some fatlike compounds also turn on production of nerve chemicals. For example, eating choline-rich foods boosts acetylcholine production. The levels and activity of these neurotransmitters are sensitive to food intake, and changes in dietary patterns can have profound effects.

Serotonin: General Mood Regulator

The neurotransmitter serotonin performs a variety of functions. High serotonin levels boost your mood, curb your food cravings, increase your pain tolerance, and help you sleep like a baby. Low levels of serotonin result in insomnia, depression, foodcravings, increased sensitivity to pain, aggressive behavior, and poor body temperature regulation.

No other neurotransmitter is as strongly linked to your diet as is serotonin. This neurotransmitter is manufactured in the brain from an amino acid called tryptophan, with the help of a variety of nutrients including vitamins B6 and B12, and folic acid. As blood and brain levels of tryptophan rise and fall and as vitamin intake fluctuates between optimal and deficient, so follow serotonin levels. Serotonin levels rise twofold when people take tryptophan supplements, which reduce the time it takes for an insomniac to get to sleep; boost mood in people battling depression; calm people prone to violence; increase tolerance to pain; and help curb carbohydrate cravings. People who take medications—such as fenfluramine, for weight loss—that boost serotonin activity also report improvements in mood and a drop in calorie intake. This serotonin-stimulating drug also increases alertness and sociability and decreases feelings of tiredness and irritability. (A cousin to tryptophan available in supplements is 5-hydroxytryptophan [or 5-hydroxy-L-tryptophan (5-HTP)], which improves mood in some people, but whether it is safe or effective for other symptoms of serotonin deficit is unknown.)

Ironically, eating a protein-rich meal lowers brain tryptophan and serotonin levels, and eating a carbohydrate-rich snack has the opposite effects. Tryptophan is a large amino acid that shares an entry gate into the brain with several other large amino acids, such as tyrosine. When you eat a protein-rich meal, you flood the blood with both tryptophan and its "competing" amino acids, and they fight for entry into the brain. Tryptophan gets crowded out, and only a small amount gets through the blood-brain barrier (the series of membranes, enzymes, and blood vessels that separate the brain from the body and, as a whole, act as the gatekeeper protecting the brain from harmful substances, such as some drugs, radioactive compounds, and disease-causing viruses). (See Illustration 1.2, on page 12.) As a result, serotonin levels do not rise appreciably after a meal or snack that contains protein, even if that food is high in tryptophan.

In contrast, a carbohydrate-rich meal triggers the release of insulin from the pancreas. This hormone causes most amino acids floating in the blood to be absorbed into the body's (not the brain's) cells—all, that is, except tryptophan, which remains in the bloodstream at relatively high levels. With the competition removed, tryptophan can freely enter the brain, causing serotonin levels to rise. The high serotonin levels increase feelings of calmness or drowsiness, improve sleep patterns, increase pain tolerance, and reduce cravings for carbohydrate-rich foods. (See "Diet and Serotonin Levels," on page 17.)

Dopamine and Norepinephrine: Mood and Energy Elevators

Dopamine and norepinephrine (also called noradrenaline) are manufactured from the amino acid tyrosine with the help of several other nutrients, including folic acid, magnesium, and vitamin B12. When your dopamine and norepinephrine levels drop, you're more likely to feel depressed, irritable, and be moody; consuming more tyrosine boosts levels of these neurotransmitters and improves mood, alertness, ability to cope with stress, and mental functioning.

Like tryptophan, tyrosine is found in protein-rich foods. Unlike tryptophan, tyrosine levels in the blood and brain rise when a person consumes pure tyrosine or, to a lesser extent, eats a protein-rich meal. The same processes that lower tryptophan levels—that is, high levels of competing amino acids and no insulin—are the very processes that favor tyrosine. Consequently, tyrosine and tryptophan are at odds with one another: For tryptophan/serotonin levels to rise, tyrosine levels must be low; conversely, when tyrosine and its corresponding neurotransmitters are high, tryptophan levels are moderate to low.

This seesaw relationship between tyrosine and tryptophan results in a similar effect on appetite. Eat a carbohydrate-rich breakfast, such as pancakes or waffles, and serotonin levels rise, which will shut off the desire to eat more carbohydrates. At the next meal you'll be more likely to select a low-carbohydrate, high-protein selection, such as a tuna sandwich with milk, which raises dopamine/ norepinephrine levels. And so we swing back and forth from carbohydrates to proteins throughout the day, in part because of fluctuations in these neurotransmitters. To examine your own mood swings and energy levels, try Quiz 1.1, "What You Eat and How You Feel," on page 19.

Diet and Serotonin Levels

Different food components have different effects on serotonin.

Sugar (sweets): Triggers quick release of insulin that lowers blood levels of most large amino acids except tryptophan, which remains in the blood and can enter the brain. As a result, serotonin levels rise, but blood-sugar levels also rise and fall dramatically.

Refined starch (white bread, white rice): Triggers release of insulin that lowers blood levels of most large amino acids except tryptophan, which remains in the blood and can enter the brain. As a result, serotonin levels rise, but blood-sugar levels also rise and fall, sometimes to levels too low.

Whole-grain starch (whole wheat brown rice, oatmeal): Triggers a slow, sustained release of insulin that lowers blood levels of most large amino acids except tryptophan, which remains in the blood and can enter the brain. As a result, serotonin levels rise gradually, and blood-sugar levels remain stable, without the rise and fall experienced with sugar or refined grains.

Vitamin B6: Aids in the manufacture of serotonin. A deficiency of this B vitamin reduces serotonin production and affects mood and food cravings.

Estrogen: Might inhibit vitamin B6 status and decrease brain serotonin levels by its effects on neuropeptide Y (NPY).

Tryptophan: Raises blood levels, then brain levels of tryptophan, which increases serotonin production.

Protein: Raises blood levels of all large amino acids. As a result, only small amounts of tryptophan enter the brain, serotonin levels do not rise, and cravings for carbohydrates might increase. A person also might feel energetic and more clearheaded as a result of lowered serotonin levels.

Fat: Omega-3 fatty acids in fish oil raise serotonin levels, although how they do this is unclear.

Raising blood levels of tryptophan always increases the manufacture of serotonin in the brain, but raising blood levels of tyrosine increases dopamine and norepinephrine levels only if:

1. The nerve cells are using these neurotransmitters and need more; or

2. Nerve cell numbers are reduced, as in aging.

In the second case, fewer cells are working harder (that is, sending more messages and needing more neurotransmitters) in an attempt to compensate for the dwindling numbers of cells. Tyrosine supplements boost dopamine levels in Parkinson's disease patients with degeneration of the nerves that produce dopamine.

A building block for tyrosine, the amino acid phenylalanine, is found in the brain in small amounts. Although its structure resembles that of amphetamines, it is unknown whether phenylalanine can affect behavior or curb appetite. However, a few studies show that this amino acid might help curb depression and improve symptoms of attention deficit disorder in adults.

Acetylcholine: The Memory Manager

When it comes to choline, the food-and-mood link is straightforward. Unlike amino acids, which must compete for entry into the brain, the fatlike substance choline has no competitors. The more you consume, the more it makes its way into the brain, where it is converted to a neurotransmitter called acetylcholine. This nerve chemical is important in memory and general mental functioning; dwindling acetylcholine levels, which are common with aging, result in memory loss and reduced thinking ability. Choline also might be effective in the treatment of tardive dyskinesia (a nerve disorder characterized by uncontrollable movements), mania, and possibly Alzheimer's disease. You can boost brain levels of choline by consuming choline-rich foods such as wheat germ and eggs, taking lecithin or choline supplements, and/or taking nicotinamide (a form of the B vitamin niacin), which enhances brain concentrations of choline.

The Survival Chemicals: Neuropeptide Y (NPY), Galanin, and the Endorphins

As we have seen, single nutrients in the diet can make or break your mood. An army of nerve chemicals produced by the appetite-control center in your brain, called the hypothalamus, have the same sort of influence. The nerve cells that regulate sexuality and the group of nerve cells that control eating are in constant communication. When these cells receive messages that fuel stores are threatened (as a consequence of strict dieting or even after an overnight fast), they release an array of appetite-stimulating neurotransmitters, including neuropeptide Y (NPY), galanin, and the endorphins, to perk up our desires to eat. According to Sarah Leibowitz, Ph.D., professor of psychology at Rockefeller University, it is no coincidence that this region of the brain also is the control tower for reproduction. The ability to reproduce, and thus keep our species alive, requires that we maintain well-stocked energy and fat stores.

The Role of Neuropeptide Y (NPY)

NPY—in combination with blood-sugar levels, serotonin, noradrenaline, and another nerve chemical, called gamma-aminobutyric acid (GABA)—turns on your desire for carbohydrate-rich foods. In essence, as NPY levels go up, so do your cravings for sweets. The link is clear. Inject NPY into the hypothalamuses of animals, and they start munching grains and sweets and ignoring fatty foods; the higher their NPY levels, the more they enjoy their carbs, while their carbohydrate cravings dwindle as NPY levels decrease. A quick-weight-loss diet is likely to send NPY levels soaring, so don't be surprised after starting such an eating plan if you are soon battling uncontrollable food cravings.

NPY jump-starts the eating cycle in the morning. Sugar stores (glycogen) in the muscles and liver are drained during the night as we sleep; waning blood-sugar levels send a message to the brain to release NPY. This neurotransmitter subtly convinces us to eat waffles, pancakes, toast, jelly, doughnuts, and other carbohydrate-rich foods for breakfast.

Stress also triggers NPY production. In this case, a stress hormone, corticosterone from the adrenal gland, triggers NPY production and activity. Elevated NPY levels also are found in obese people, suggesting that this nerve chemical might contribute to excessive food intake and weight problems.

Galanin at a Glance

A different set of nerve chemicals from the hypothalamus often influences whether and when you want fatty foods. These neurotransmitters include galanin and the endorphins. As galanin levels rise, so does your desire to eat foods that contain fat, such as salad dressing, chocolate, meat, or potato chips. Quite simply, the more galanin your hypothalamus produces, the more fat you eat.

What causes galanin to be released? The breakdown of body fat, which occurs during dieting or when several hours have passed between meals, releases fat fragments (called free fatty acids) into the blood that travel to the hypothalamus in the brain and trigger the release of galanin. Elevated galanin levels, in turn, trigger cravings for fat-containing foods, from ice cream to a hamburger. Reproductive hormones such as estrogen, the stress hormones including cortisol, elevated insulin levels, and possibly the endorphins also turn on galanin, while the neurotransmitter dopamine might turn off galanin release. This can explain the cravings that often accompany premenstrual syndrome (PMS) in women, which occur when estrogen levels fluctuate throughout the menstrual cycle.

Galanin works in concert with other neurotransmitters, such as the endorphins and serotonin, and might have a slight stimulating effect on your carbohydrate intake. In addition to increasing our cravings for fat, galanin affects how much of that dietary fat is stored as body fat—again.

As you might imagine, NPY and galanin levels fluctuate during the day. While NPY levels are high in the morning, galanin levels begin to rise by early afternoon and peak in the evening. The NPY-induced desire for carbohydrates provides quickenergy fuel in the morning, and the galanin-induced desire for fattier foods later in the day is possibly the body's attempt to store longer-term energy in anticipation of the overnight fast (see Illustration 1.3). Managing these neurotransmitters to curb cravings, boost mood, and manage your weight will be discussed in the chapters 2, 3,5,6, 10, and 11.

The Endorphins: The Natural High

The endorphins are your body's natural morphinelike chemicals that help boost your tolerance to pain, calm you during stress, and produce feelings of euphoria and satisfaction. They are released during intense exercise and are the underlying cause of "runner's high"—that feeling of joy and peacefulness that many athletes experience during and following exercise. Laughter, soothing music, meditation, and other pleasurable experiences also raise endorphin levels.

Endorphins make eating tasty, sweet, or creamy foods fun. When animals are injected with a medication that increases endorphin levels, they eat more; medications that block endorphins curb the desire for tasty foods. Similarly, endorphins in our bodies have no effect on our regular eating habits (they won't encourage you to eat more wheat germ or broccoli!); they only increase our desire for cakes, cookies, ice cream, and creamy candy. Satisfying those endorphin cravings is selfperpetuating because these foods further raise endorphin levels in the brain, which explains why you want to eat an entire box of chocolates once you start! The very taste of something sweet on the tongue immediately releases endorphins in the brain, making the sweet treat instantly enjoyable.

Elevated endorphins also contribute to a pregnant woman's longings for certain foods (in conjunction with the female hormone progesterone); a woman's uncontrollable cravings the two weeks before her period; a sweet tooth during times of stress; cravings for alcohol in an alcoholic; and overeating in obese people, binge eaters, and bulimics. The pleasurable feelings associated with eating tasty foods are further enhanced by other neurotransmitters, such as gamma aminobutyric acid (GABA).

Beyond the Brain

The symphony of nerve chemicals that dictate your food preferences and mood are not housed exclusively in the brain. Some play their music from distant regions in the body, such as the digestive tract, pancreas, adrenal glands, and fat tissue. Cholecystokinin (CCK) is a hormone found in both the brain and the small intestine that aids in digestion and contributes to feelings of satiation. The female hormone estrogen enhances CCK's effectiveness. The more CCK that is released, the slower you digest food, the faster you feel full, and the less food you eat. Studies show that animals lose their interest in sugar when CCK is injected into their brains. In studies on people, we see that low levels of CCK are found in those with eating disorders, such as bulimia, which might partially explain why they don't feel full even when they've eaten huge amounts of food. In contrast, AIDS patients with high CCK levels and low endorphin levels are likely to lose their appetites, which contributes to the wasting syndrome associated with this disease. The amino acid phenylalanine increases CCK levels, which has led to its inclusion in some weight-loss supplements but still has not made them effective for weight loss.

Somatostatin and glucagon also are released from the digestive tract in the presence of food, and they signal the brain to stop eating. Somatostatin slows digestion, which distends the stomach and gives us the feeling of fullness. Starvation results in excessive somatostatin in anorexics, which might explain why they feel full after eating tiny amounts of food. Obese people, on the other hand, secrete small amounts of somatostatin during a meal, so they are more likely to overeat. Glucagon tells us when we've had enough protein.

Enterostatin is another hormonelike compound released from the intestines that reduces fat consumption and, at least in animals, helps reduce body weight by "burning" fat tissue. Although its role in digestion is not fully understood, enterostatin might encourage feelings of fullness, so a person eats a little, but not a lot. It is likely that enterostatin, serotonin, galanin, and the endorphins work in concert to raise and lower cravings for fatty foods, from salad dressing and mayonnaise to meat and chocolate.

The Highs and Lows of Blood Sugar

Blood sugar is at the helm of your appetite and mood control. An army of hormones, including glucagon from the pancreas, epinephrine and the glucocorticoids from the adrenal glands, and thyroxin from the thyroid gland, raise blood-sugar levels when they fall below normal concentrations. Insulin balances the effects of these hormones by lowering blood-sugar levels when they rise too high.

When we digest the food we eat, our bodies break down sugars and starches into their simple units of glucose or fructose. These simple sugars enter our bloodstreams and trigger the release of insulin from the pancreas. Insulin—with the help of other nutrients such as chromium, magnesium, and manganese—ushers blood sugar into the cells of our bodies, thus supplying energy to the tissues and maintaining normal blood-sugar levels.

However, not all carbohydrates are created equal. Insulin secretion mirrors blood-sugar levels. Unprocessed, complex carbohydrates (starches such as the carbohydrates found in whole-grain breads and cooked dried beans) are made up of hundreds of glucose units linked together like high-energy pearls on a string. They are broken down slowly in the digestive tract and gradually enter the bloodstream, producing a mild and progressive elevation in blood-sugar and insulin levels. Processed starches, such as white bread or white rice, and concentrated sugars, such as table sugar or sweets, are more rapidly converted into simple sugars that enter the blood and trigger a larger release of insulin from the pancreas. When you eat a sweet snack, insulin funnels the excess sugar out of the blood and into the cells, decreasing blood-sugar levels, sometimes below normal levels, while elevated insulin levels linger for hours. The sugar-induced rapid rise in insulin might arouse your hunger signals as well, according to Judith Rodin, Ph.D., professor of psychology and psychiatry at Yale University. Her research shows that people are hungriest and like sweet tastes more when their insulin levels are high. You can see from this cycle why it seems that the more sweets you eat, the more sweets you crave.

The Effects of Dietary Habits on Blood Glucose

Skip a meal: Blood glucose levels drop slowly and, in the case of breakfast, might only partially rise to normal levels if food intake is delayed too long.

Skip two meals: Limited glycogen stores are mobilized to maintain blood-sugar levels; stores are exhausted within twenty-four to forty-eight hours of fasting. The release of fat fragments results in increased levels of galanin, which triggers cravings for fatty foods.

Eat only sugar or sweets (desserts, candy): Blood sugar quickly (within ten to fifteen minutes) rises to above-normal levels, followed within twenty-five to forty minutes by a dramatic drop in blood sugar to subnormal levels.

Eat only refined starches (white bread, refined cereal): Blood-sugar levels rise less quickly than sugar, but still can rise too high, resulting in too much insulin released from the pancreas and a drop in blood sugar to subnormal levels, but not as dramatic as is experienced with sugar.

Eat whole-grain starches (whole wheat bread, whole-grain cereal): Blood-sugar levels rise slowly and steadily for up to four hours. Insulin is released in small, steady amounts from the pancreas, resulting in even blood-sugar levels and no dramatic drop in blood sugar as is seen with sugar or refined grains.

Eat a mixture of protein and carbohydrates (turkey on whole wheat bread): Blood-sugar levels stabilize for up to three to four hours.

Drink alcohol: Blood-glucose levels might be slightly reduced for a short time—less than one hour

Drink caffeine (coffee, tea, cola, soft drink): Blood-sugar levels rise in the first hour, followed by a drop in glucose to subnormal levels.

But the cycle does not stop there, since blood insulin levels also correspond to body fat stores. The more often and the longer blood insulin levels remain high, the more likely a person is to accumulate excess body fat and battle a weight problem. Since body fat is linked to galanin activity, and insulin is linked to serotonin, CCK, and CRH, it is likely these tissues, hormones, and brain neurotransmitters (and possibly hormones from the adrenal glands, such as the stress hormones, including cortisol) work as a team, with imbalances resulting in powerful urges to eat too much and gain weight (see "The Effects of Dietary Habits on Blood Glucose," above).

What Makes Us Stop Eating?

With such an orchestra of chemicals telling us to eat, you might be thinking that it's amazing we ever leave the dinner table at all! Fortunately, the brain has a feedback system that tells the body when it's had enough to eat. NPY levels drop and serotonin levels rise after we eat a waffle, putting a halt to our carbohydrate cravings. Galanin levels are kept in check by eating some, but not too much, fat. Other neurotransmitters, such as corticotropin-releasing hormone (CRH), curb hunger, especially during times of stress and long-term dieting. Inject CRH into the brains of animals and they cut back on their food intakes; drugs that block CRH return those animals to their normal eating habits. This chemical also reduces our desire to try new foods and is probably one reason why some people lose their appetites when they are stressed or are fasting.

The body also has checks-and-balances on brain activity when it has had enough to eat. CCK is released from the intestines after a meal and sends messages of satiation to the brain. It also interacts with CRH. Elevated insulin levels in the blood after a meal also switch off NPY levels and turn on CRH in the brain, which curbs appetite. In addition, leptin is released from fat tissue and tells the brain to shut off NPY and increase CRH. Estrogen released from the ovaries can turn off appetite by stimulating the release of CRH and suppressing the release of NPY as well. Of course we can tamper with these checks-and-balances by the medications we use (the birth control pill suppresses CCK; cortisone increases insulin levels), how much we exercise (physical activity helps normalize endorphin levels), how much stress we experience (stress elevates cortisol levels, which increases our preference for fatty foods), and what we eat. This will be discussed in more detail later in this book, especially in chapter 7.

The new wave of weight-loss medications is attempting to regulate this symphony of appetite-control chemicals. Drugs that raise CCK levels have come and gone as we have seen that the body develops a tolerance to orally administered CCK. Fenfluramine and another serotonin-boosting drug called dex-fenfluramine entered the market with mixed reviews and serious side effects, such as high blood pressure. Other serotonin-regulators and medications that decrease NPY levels are now being tested, and leptin is being considered as a potential drug for treating obesity. How useful these drugs will be in the long run is questionable when you consider the complexity of our appetite-control symphony of chemicals. As you have seen, no one neurotransmitter works alone, but rather each works in concert with numerous otherneurotransmitters, hormones, and chemicals in the delicate and complicated task of regulating our eating. Tampering with only one or two of the players in that concert is likely to have an unforeseen cascade effect on other chemicals instead of directly influencing our food choices alone. As you read this book you will learn that gently and naturally nudging brain chemistry into balance can be accomplished, at least in part, by making a few changes in what and when you eat.

When Eating Becomes Unhealthy

Eating is a pleasure for most people, but for those people preoccupied with food and thinness, it is a nightmare. Anorexia nervosa (self-starvation), bulimia nervosa (excessive food intake, followed by vomiting or purging), binge eating (excessive eating episodes with no vomiting), and even obesity share many common causes, traits, and symptoms. No one knows exactly why some people develop eating disorders and others try dieting but return to normal eating. Eating habits rest on a continuum from healthy to deadly, with common habits like dieting sometimes spiraling into an eating disorder as the fear of being fat becomes an obsession that is fueled by diet-induced imbalances in the body's appetite-control chemicals. Even if emotional issues such as a desire to lose weight initiate an eating-related disorder, physical and chemical factors help perpetuate it. Studies have shown that hormones and nerve chemicals from growth hormone, prolactin, cortisol, and estrogen to NPY, the endorphins, serotonin, vasopressin, and CCK are turned topsy-turvy in people prone to obesity and in those suffering from eating disorders.

Upsets in CCK, Serotonin, NPY, and Endorphins

Erratic eating habits, such as dieting, starvation, or bingeing, send many of these appetite-control chemicals into a tailspin, thus perpetuating and escalating the problem. For example, CCK (see paragraph above) is released in small amounts in bulimics; consequently, their brains don't receive the signal to stop eating, or their systems become so desensitized to CCK that they eat faster and larger quantities of food before they feel satisfied. In contrast, semistarvation in anorexics oversensitizes their CCK system, so they feel full after eating even a few bites of food. Other neurotransmitters and hormones that are turned upside down in people who battleeating disorders or obesity include leptin, cortisol, bombesin (an appetite-suppressing chemical produced in the digestive tract), ACTH, CRH, and oxytocin (a neurotransmitter that aids memory and that might turn on and off our salt cravings).

Most bulimics report that a binge is triggered by cravings for specific foods, in particular sweets, and this is fueled by upsets in NPY and serotonin. In addition, NPY levels are elevated in anorexics who binge, and are very high in bulimics, which might override normal signals of satiety and contribute to their compulsion to overeat sweet and starchy foods. On the other hand, low levels of serotonin in bulimics encourage them to binge on sweets. Working with these fluctuations in neurotransmitters could help curb the symptoms of some eating disorders. Bulimics who have high blood tryptophan levels are more likely to stop the binge-and-purge cycle and suffer less depression than are bulimics who have low tryptophan levels. Knowing this, we can suggest that bulimics might sidestep a binge if they ate small amounts of carbohydrate-rich foods throughout the day to maintain a steady rise in serotonin.

Dr. Leibowitz suspects that imbalances in endorphins are common in bulimia, anorexia, and obesity, and might contribute to these eating disorders. For example, bulimic women who have low endorphin levels are more likely than people with higher endorphin levels to be depressed and to binge on sweet and creamy foods, such as ice cream, chocolate, and pie, possibly in an attempt to raise endorphin levels and elevate mood. Drugs that block endorphin levels in obese people, binge eaters, and bulimics also work to reduce food intake and binge eating, possibly by preventing wide fluctuations in endorphin levels that can lead to overeating. In contrast, anorexics can be addicted to the endorphin rush of starvation, which can sabotage treatment and result in an overwhelming desire to avoid food. The good news is that endorphin levels eventually return to normal in both bulimics and anorexics when they resume normal eating habits.

What's Wrong with Me?

Whatever begins the dieting spiral, it is likely that imbalances in this chemical stew are major reasons why eating disorders progress into the serious conditions that they do. A person might start out with a normal balance of nerve chemicals, but prolonged starvation or binge-and-purge cycles upset these appetite-control chemicals, which will normalize only when regular eating habits are resumed in both anorexics and bulimics.

However, there are some people who are born with imbalances in one or more nerve chemicals that genetically programs them to gain weight. Some in this categoryadopt bizarre eating habits in a desperate attempt to avoid obesity and remain fashionably thin. Other people have imbalances in appetite-control chemicals, such as endorphins and serotonin, that influence their hunger and satiety signals and make them more likely to develop eating disorders. Some people have imbalances in neurotransmitters that lead to emotional problems, such as substance abuse or depression, psychological problems that in turn lead to an eating disorder.

Knowing that the uncontrolled eating or self-imposed starvation is fueled by these powerful internal chemicals and their interactions can help remove some of the blame and guilt that often have been tied to eating disorders. This knowledge also has helped steer research toward developing medications that reset the nerve chemical balance and restore normal eating behaviors in anorexic and bulimic patients. However, the treatment of eating disorders continues to be multifaceted, encompassing counseling, dietary changes, and behavior changes. If attitudes and eating habits are changed and, in the case of anorexics, if weight is normalized, appetite-control chemicals also return to normal. If a person can conquer the initial hurdles in the treatment for eating disorders, there is hope that full recovery can occur.

Nature Versus Nurture

Just as you are born with a particular shape to your nose, a unique color to your eyes, and are destined to reach a certain height (assuming you are not malnourished), you also are born with an inherent neurotransmitter profile. In the laboratory, different rats with different personalities also self-select different combinations of foods. Some rats love fat and, if allowed to eat all they want of whatever they want, choose up to 60 percent of their calories as fat. Most of these fat-craving rats also are obese, but not all of them. Other rats love carbohydrates and ignore the fat. Most of these are lean, unless their preferences are for sweets, in which case they are likely to be overweight. Similarly, not all people's food preferences and responses to foods are created alike.

You can't change your genes and what they might dictate you to eat, but you can coax your neurotransmitters, through a few simple dietary and lifestyle changes, to influence what foods will appeal to you. Even slight changes in your appetite- and mood-control chemicals can have dramatic effects on your mood, eating and sleeping habits, ability to think and remember, and personality. If your eating habits are fueling any mood problems you have, even minor changes in when and what you eat can help you change your habits and begin to feel and think your best.

How Are You Eating? A Self-Assessment

You can't decide where you are going until you know where you have been. So before reading further, take a few minutes to complete the following dietary self-assessment. Keep in mind that the more honest and accurate you are, the more feedback you will have on your current eating habits. This, in turn, will help you decide what eating patterns you have that might need changing and which ones support a healthy, active mind, body, and mood. The results of this assessment will be used in conjunction with the Food & Mood Journal on page 282 to help you tailor the Feeling Good Diet (see chapter 12) to your personal food preferences, lifestyle, and nutritional needs.

Quiz 1.2 A Self-Assessment of Your Diet

Choose the answer that most closely describes your eating habits, even if it isn't a perfect fit There are no right or wrong answers. This self-assessment provides feedback on your current eating habits so you can compare what you currently are eating to the guidelines for the Feeling Good Diet in chapter 12. This is the starting point for planning how and what you want to change.

DIETARY QUESTIONS

1. What is the best example of your most typical eating style?

a. I eat five or six mini-meals and snacks evenly divided throughout the day.

b. I eat three square meals a day.

c. I nibble all day, perhaps eating eight or more times in a day.

d. I eat sporadically One day I skip breakfast and lunch, then eat a large dinner. The next day I might eat breakfast and several snacks, but skip dinner.

2. What is your average calorie intake?

a. More than 2,500 calories a day.

b. 1,600 to 2,500 calories a day.

c. 1,000 to 1,600 calories a day.

d. Because I diet frequently, my calorie intake varies from fewer than 1,000 calories to more than 2,500 calories a day.

3. Do your eating habits fluctuate?

a. Rarely. I usually eat about the same types of foods at about the same times during the day.

b. Somewhat, although I skip a meal or eat larger/smaller meals a couple of times during the week.

c. Often. My eating habits vary almost daily.

d. Always. I regularly skip meals; grab snacks on the run; forget to eat all day, then eat a large dinner; and/or switch from one eating style to another.

4. Do you eat breakfast?

a. Yes, always.

b. Usually (at least four days a week).

c. Sometimes (fewer than four days a week).

d. Seldom.

5.. If you eat a morning meal, which of the following best represents your typical breakfast?

a. Cereal or toast, milk, fruit.

b. Eggs, bacon, toast with butter, coffee.

c. Doughnut and coffee.

d. Coffee or tea.

6.. Do you eat lunch?

a. Yes, always.

b. . Usually (at least four days a week).

c. . Sometimes (fewer than four days a week).

d. . Seldom.

7.. If you eat a midday meal, which of the following best represents your typical lunch?

a. A grain such as pasta or bread, meat, and a vegetable, or a large salad that contains some meat or cheese and a roll.

b. A large meal, such as a hot roast beef sandwich with gravy and mashed potatoes.

c. A fast-food lunch, such as a hamburger, French fries, and a beverage.

d. Coffee, candy bar, or soda pop.

8.. Do you eat an evening meal?

a. . Yes, always.

b. . Usually (at least four days a week).

c. . Sometimes (fewer than four days a week).

d. Seldom.

9. If you eat an evening meal, which of the following best represents your typical dinner?

a. . I keep dinner light and usually have small portions of fish, salad, pasta, and/or fruit.

b. Dinner is my biggest meal and can include generous portions of meat, vegetables, and bread or potato.

c. . A frozen entree or a meal-replacement drink.

d. . I usually skip dinner or grab something from a fast-food restaurant.

10.. What do you eat most frequently for a snack?

a. . Fruits and vegetables, whole-grain breads, or yogurt.

b. . Cookies, potato chips, or granola bars.

c. Candy bar, doughnut, or French fries.

d. . Nothing. I seldom or never eat between meals.

11. What types of foods do you consume between dinner and bedtime?

a. . Fresh fruits and vegetables, whole grains, or low-fat milk products.

b. . Snack foods, such as popcorn, crackers, potato chips, or other convenience foods.

c. Chocolate, cola soft drinks, hot cocoa, or coffee or tea.

d. . I do most of my overeating in the evening, including large bowls of ice cream with chocolate sauce, or second servings of leftovers from dinner.

12.. How frequently do you have strong cravings for starchy or sugary foods?

a. Seldom.

b. . Only during certain times of the month or year, such as the two weeks before my period, or in the winter.

c. . Frequently.

d. Daily, and the urges often lead to overconsumption of the craved food.

13.. How many servings of unsweetened fruits and plain vegetables (fresh fruit and vegetables or fruits canned in their own juice and plain frozen vegetables) do you eat in an average day?

a. Eight or more.

b. . Five to seven.

c. Three to four

d. Fewer than three.

14. Of those fresh fruits, how many are vitamin C-rich selections, such as oranges, grapefruit, or cantaloupe?

a. Three or more.

b. Two.

c. One.

d. . Fewer than one each day.

15. Of those fresh or plain frozen vegetables, how many are dark green, such as romaine lettuce, spinach, or broccoli, or dark orange, such as sweet potatoes and carrots?

a. Three or more.

b. . Two.

c. One.

d. . Fewer than one each day.

16.. How many servings of grains, such as bread, cereal, pasta, noodles, rice, or tortillas, do you typically eat each day (one serving = one slice of bread, one tortilla, or½ cup cooked grains)?

a. More than eight.

b. Six to eight.

c. Five to six.

d. Fewer than five.

17. Of these grains, how often are the choices whole grain?

a. All the time.

b. One out of every two choices is whole grain.

c. Occasionally I select whole grains.

d. Seldom or never.

18. Of these grains, how often do you choose crackers, waffles, sugarcoated cereals, tortilla chips, buttered popcorn, or other grains with added fat and sugar?

a. Seldom or never.

b. Occasionally (two or three times a week).

c. Frequently (once a day).

d. Most of the time (more than once a day).

19. How many servings daily of extra-lean red meat, chicken, fish, and cooked dried beans and peas do you eat (one serving = 3 ounces of animal flesh or¾ cup of beans)?

a. Three to four

b. . Two.

c. One.

d. None.

20. When you eat meat, how often do you trim the visible fat, remove the chicken skin before cooking, and cook without using oils and fats such as butter and margarine?

a. Always.

b. Usually.

c. Sometimes.

d. Seldom or never.

21.. How many glasses of milk or 8-ounce servings of yogurt do you consume in a day?

a. Three to four

b. Two.

c. One.

d. None.

22. What type of milk products, including milk, yogurt, and cheese, do you usually consume?

a. Nonfat (nonfat milk, nonfat yogurt, fat-free cheeses).

b. Very low-fat (1 percent low-fat milk- yogurt made from a mixture of nonfat and low-fat milk; and low-fat cheeses).

c. . Low-fat (2 percent low-fat milk; yogurt made from 2 percent milk; reduced-calorie or "light" cheeses).

d. Whole milk (yogurt made from whole milk; regular cheeses).

23.. How often do you snack on cookies, candy, fruited-yogurt, and other sweets (one snack serving = two small cookies, one small candy bar, one 8-ounce yogurt, etc.)?

a. Once a day or less.

b. . Twice a day

c. Several times a day.

d. . Several times a day, and often in large amounts; I'll eat half a bag or more of cookies in the evening.

24.. What do you usually eat for dessert?

a. I seldom eat dessert and if I do, it's fresh fruit.

b. . Small servings of nonfat ice cream or sorbet, oatmeal cookies, or angel food cake.

c. . Moderate-sized servings of ice cream, pie, pastries, cake, or cheesecake.

d. Large servings of pie or cake and ice cream, candy, or other sweets. Sometimes I eat right from the cake or pie without portioning off a serving.

25.. How often do you add sugar to your foods, including coffee or tea, cereal, and/or fruit?

a. Never.

b. Sometimes.

c. . Frequently.

d. All the time.

26. What is your typical weekly consumption of soda pop, including diet sodas?

a. None to three 12-ounce cans each week.

b. Four to six 12-ounce cans each week.

c. Seven to ten 12-ounce cans each week.

d. More than ten 12-ounce cans each week.

27. How many cups (5-ounce servings) of caffeinated coffee or tea do you drink on a typical day?

a. I don't drink caffeinated coffee or tea.

b. . Two to three 5-ounce cups or fewer.

c. Four 5-ounce cups.

d. Five or more 5-ounce cups.

28.. What is your average alcohol consumption for the week? (One drink is a 6-ounce glass of wine, I ounce of hard liquor, or a 12-ounce can of beer.)

a. I average less than five drinks a week, or do not drink at all.

b. I average a drink a day.

c. I average ten drinks a week.

d. I average two drinks or more a day.

29. How often do you bake, steam, broil, poach, or grill food rather than fry, saute, or use sauces and gravies that contain fat?

a. Always.

b. Usually.

c. At least 50 percent of the time.

d. Seldom or never.

30. How often do you saute in water, broth, herbs, or other no-fat liquids?

a. Always.

b. Usually.

c. Often.

d. Seldom or never.

31. How often do you use tomato-based or no-fat sauces on pasta rather than creamy sauces or sauces with fatty meats?

a. Always.

b. . Usually.

c. . Often.

d. Seldom or never.

32. How much salad dressing do you use?

a. I use fat-free salad dressing or use 2 teaspoons or less of oil-based dressing on my salads.

b. . I use low-fat dressing and limit the serving to 2 tablespoons.

c. . I use regular salad dressing and limit the serving to 3 tablespoons.

d. I use generous servings of regular salad dressings (more than 3 tablespoons) and eat salads regularly.

33.. How often do you eat in fast-food restaurants?

a. . Less than once a week.

b. . Once a week.

c. Twice a week.

d. More than twice a week.

34. How often do you use butter, margarine, oils, whipping cream, sour cream, whipped toppings, mayonnaise, and shortening?

a. Seldom.

b. . Once a day.

c. Several times a day.

d. I couldn't cook or eat without these foods.

35. How often do you read labels and select foods that contain 3 grams of fat or less for every 100 calories?

a. Always.

b. Usually.

c. Often.

d. Seldom or never.

36. How many glasses of plain water do you drink daily?

a. . Six or more glasses.

b. . Four to five glasses.

c. Two to three glasses.

d. I seldom drink water

37. How often do you limit intake of salty foods and avoid using salt in food preparation or at the table?

a. Always.

b. . Usually.

c. Often..

d. . Seldom or never.

38. What is your current weight?

a. I'm within 10 percent of my desirable body weight.

b. . I'm approximately 15 pounds or more overweight.

c. . I'm approximately 15 pounds or more underweight.

d. I'm more than 20 pounds overweight.

39.. How often have you dieted to lose weight in the past?

a. I've been on fewer than three weight-loss diets in my life.

b. I've been on four to six weight-loss diets in my life.

c. I've been on seven to ten weight-loss diets in my life.

d. I've lost count. I'm always trying new diets to lose weight.

40.. What type of supplement(s) do you take?

a. A daily multiple vitamin and mineral supplement, extra calcium, vitamin C, and/or vitamin E.

b. A moderate-dose vitamin supplement.

c. I'm not sure what to take, so sometimes I supplement and sometimes I don't.

d. I know my eating habits are not the very best, but I either don't take supplements or I fluctuate between not taking anything and taking large doses of single-nutrient supplements.

GENERAL HEALTH QUESTIONS

41.. How often do you feel, look, act, and function at your best?

a. Most of the time.

b. . At least 50 percent of the time.

c. I get by most of the time, or am down more often than I'm up.

d. I seldom feel really good.

42. How frequently do you engage in planned exercise?

a. . Five or more times a week for at least thirty minutes each time.

b. Three or more times a week for at least thirty minutes each time.

c. Fewer than three times a week.

d. I don't exercise.

43. How frequently do you take time out for yourself—e.g., read a book, take a walk in the woods, visit with a friend, take a hot bath, work on hobbies?

a. Daily.

b. At least a couple of times a week.

c. Once a month.

d. I don't remember the last time I had a moment's peace.

44. How often do you discuss your personal concerns with a close friend or family member?

a. Daily or at least several times a week.

b. Occasionally, when things get bad.

c. Seldom.

d. I have no one to talk things out with.

The following questions are not part of the preceding quiz. Your answers to these questions will help you assess your eating habits.

45. Do your eating habits change when you are sad, irritable, depressed, or lonely; happy, excited, stressed, or with friends; or when you are tired, lacking in sleep, or not feeling up to par?

Yes__No__

If yes, when and how do your eating habits change?

46. What foods do you avoid?

47. Why do you avoid these foods?

48. Are you currently seeing a physician for any disease or problem? Yes __No__ If yes, explain.

49. Do you have a personal or family history of depression, insomnia, stress-related health problems, weight problems, premenstrual syndrome (PMS), Seasonal Affective Disorder (SAD), or other emotional or mood disturbances? Yes__ No__ If yes, explain.

50. If yes, were the symptoms serious enough to require medical attention? Yes__No__

51.. Do your eating habits change during certain times of the month or during the winter? Yes No If yes, when and how do your eating habits change?

52. Do you frequently develop colds, infections, or other signs of a weakened immune system? Yes __No__

53. Do you take any medications, including aspirin, the birth control pill or estrogen, antibiotics, or heart disease or blood pressure medications? Yes __No__ If yes, which ones?

54. Do you use tobacco or are you frequently around people who smoke? Yes __No__

Scoring:

Review your answers and tally your score for questions I through 44, giving yourself

2 points for every a answer I point for every b answer 0 points for every c answer — 1 point for every d answer

Remember: This assessment is only feedback on your current eating and lifestyle behaviors. As you read this book, return to this assessment to compare how you have been eating with the dietary recommendations for each emotional or mental problem. Which eating habits need changing? Which ones can stay the same? After reading this book and following the Feeling Good Diet, complete this assessment again (give yourself at least six months) and see how far you have come!

If you scored:

70 to 88: Congratulations! Your dietary habits are excellent. Review those questions on which you scored fewer than two points and see if you can find room for improvement. 51 to 69: Very good. Your diet is in the ballpark. A few changes could do wonders for your emotional and physical well-being. Find four questions where you scored fewer than two points and decide how you will change your eating habits to improve your score and your

mood.

37 to 50: Caution. Your dietary habits are average, which means you probably consume too much of the wrong foods and not enough of the right ones. Your diet is likely to be a contributing factor to your mood problems. Take action quickly identify five or more questions where you scored fewer than two points and make some changes today to boost your score and your moods.

Fewer than 37: Warning. What and how you are eating are major contributing factors to how you feel. The good news is you have lots of room for improvement! Start slowly by picking two or three habits where you scored fewer than two points. Make changes to boost yourscore, and when those patterns have become habit, select another two or three questions with low scores to make additional changes. Keep improving your eating habits until you score 69 or higher.

For questions 45 through 54:

45. If you answered yes, read chapters 4, 6, 7, 8, and 9.

46. and 47. Read chapters 10 and 11.

48, 49, 52, and 53. Many emotional problems stem from physical ailments or even nutrientdrug interactions. Your physician and pharmacist can explain how a medication, illness, or treatment might affect your eating habits and mood.

49 and 50. For information on PMS and SAD, read chapter 5.

51. If you answered yes, read chapter 7.

54. Smoking is a primary factor in insomnia and stress. If you answered yes, read chapters 7 and 9.

Copyright © 1995, 1999 by Elizabeth Somer