The questions I hear most often about diet are, What should I eat? Which is the best diet to follow? Behind these questions is the assumption that there is a perfect diet, and all one need do is discover it. But consider for a moment the implications of a perfect diet. Perfection implies sameness. If we all followed the perfect religion, everyone would think and act similarly. If each of us drove the perfect car or had the perfect job, we would all be parking and working in the same place. Likewise, if everyone ate the one perfect diet, we would all be eating the same food.
The most telling characteristic of the perfect diet is the hidden assumption that the body remains unchanged and has the same nutritional needs at every stage of development. But, as we know, nothing could be further from reality. If there is any guarantee that comes with living in a body, it is change. Each second ten million red blood cells are born and die. The stomach lining completely regenerates in a week, a healthy liver in six weeks, and the skin surface in a month. Scientists postulate that 98 percent of all atoms in the body are replaced within a year, 100 percent within seven years.1
From the time of conception to the flowering of adulthood, the body grows from one cell to one quadrillion cells (1,000,000,000,000,000). Total body weight may increase twentyfold to sixtyfold from birth, while brain size, muscle mass, percent of body fat, and bone density increase (or decrease) at their own particular rates.
Even within the course of a day the body undergoes a wide range of physiological changes. It rhythmically shifts in temperature, metabolic rate, respiratory function, brain wave patterns, endorphin production, serum nutrient levels, hormonal and enzymatic production, and energy output.
Perhaps the most noticeable changes in the body occur in health. We move through an endless parade of aches, pains, coughs, colds, tensions, and sensitivities along with periods of relative health and high energy. With all these changes in the body, does it not make sense that our nutritional needs change? A single diet could not possibly keep pace with those changes.
A changing body means a changing diet. You have not had just one body in this life—you have had many—and each of these bodies has called for a different way to eat. Consider the dramatic shift that occurs in the life of a newborn as it makes the transition from umbilical-cord nourishment to breast or bottle. No longer is its nutritive process a passive one through the belly. It must actively reach for milk and for the first time carry out the function of digestion completely on its own. The introduction of solid food marks yet another important transition for the child. Its body is growing at a rapid rate, and its digestive system must meet a completely new set of challenges in breaking down and assimilating complex molecular foodstuffs.
No one complains to an infant that it is getting too much fat in its diet—mother’s milk is 52 percent fat—or that it needs a wider variety of foods. For its particular physiology and activity level, it is eating the perfect diet. And yet that perfect diet will change. The infant may grow to be an active toddler, a high-school athlete, a health-food-eating college student, an office worker, a parent, a partygoer, or an invalid, with each of these different “bodies” calling for its own special nutrition.
There are five key factors that influence the changing nature of the body and hence the diet: life-style, environment, season, age, and health. These factors continually interact to form a new picture of our emotional and biological needs.
Think for a moment of the times when your life-style changed—a move to a new location, a different job or career, a shift in finances, or a change in your exercise level, sleep schedule, or recreational pursuits. Did your body have different needs? Did it change in noticeable ways? Were you drawn to different foods?
A changing life-style means a changing diet. For example, if you are working at a desk all day, physical exertion is minimized, metabolism decreases, and caloric needs drop. In other words, you require less food. If you switched to a landscaping or construction job, caloric and nutrient needs would automatically rise and your appetite would increase. Body chemistry is dramatically altered simply by switching jobs.
People working in a high-stress environment or a boring job might find themselves hungrier than usual; food serves either to calm us down or activate our interest when we feel unfulfilled. The same person who is wholeheartedly engaged and 100 percent involved in his or her job might not feel hungry for hours. People who love their job often report they have less desire for food because they are so nourished and energized by their work. Can you recall an instance when you were so absorbed in an activity that you were not hungry at mealtime?
Life-style changes also include exercise level and type. A marathon runner has different nutritional needs from a weekend jogger, while anyone training for endurance has different needs from those training for strength. Current research strongly suggests that even a moderate amount of exercise done regularly can alter metabolism and affect the rate at which we digest food, burn fat, and build muscle. People often report that upon adopting a type of exercise they have never done before or simply including any exercise into a sedentary life-style, they begin to crave certain foods. Those who begin weightlifting often desire high protein foods, particularly meat and fish. One woman who took up bicycling started to crave oatmeal cookies and bananas, and another woman who began aerobic walking lost her intense cravings for coffee and sugar.
A change in our daily schedule also brings about changes in body and diet. Many people who switch to a late night schedule or work a “graveyard shift” report digestive discomfort, weight gain, and an assortment of minor health complaints—headaches, joint pains, and grogginess. Research has revealed that digestive capacity is highest at noon, which corresponds to the hottest time of the day. Reversing our schedule so that we eat a big meal in the late evening, when digestive metabolism is at its lowest level, is a challenge to the inherent rhythms of the digestive system and naturally creates disorders in the body.
I have noted with great fascination the influence of life-style on my diet. When I was a medical student, time seemed more valuable than anything in the world, so the last thing I wanted to do was cook. I ate out twice a day, three times if you consider that breakfast was often last night’s leftovers. My diet was unusually limited because I found only two restaurants in Syracuse—a Greek restaurant and a small Mexican take-out place—that were cheap, convenient, and served what I enjoyed. For an entire year my diet consisted of falafel, chick-pea salad, bean burritos, and orange juice.
My life-style determined my diet, which in turn influenced the health of my body. I experienced chronic gas problems and stomachaches caused by the oily food, felt sluggish after meals, and was gaining weight even though I was eating less food than before. The cold weather of upstate New York coupled with my busy schedule made it difficult to exercise, and my metabolism simply slowed down.
Leaving school and moving to Southern California marked a dramatic shift. I worked as a free-lance sales manager for several health-food and vitamin companies and naturally grew more health conscious. I had little stress, plenty of free time, and lived in a beach community in San Diego where everyone seemed to exercise, sun themselves, and eat papayas. I rediscovered my body, taking long ocean swims and playing Frisbee in the park.
I also rediscovered my love for food. I ate from an abundance of locally grown fruits and vegetables, preparing fresh meals each day, and experimenting with new foods like guacamole or tofu sandwiches. Any desire for falafel or bean burritos was gone. I felt light and energized, my digestive problems disappeared, and I lost the weight gained in Syracuse even though I was eating more.
Five years later a move to New York City brought yet another life-style change. The bathing suit was replaced by a business suit. Working as a marketing and public relations consultant for food and vitamin companies, I had deadlines to meet and subways to catch. Lunch was now a “business lunch.” I was not so much concerned with what I ate as with whom I ate. I would agree to whichever restaurant my client preferred and would order food I normally would not choose—sushi, asparagus tips in lime vinaigrette, and buffalo mozzarella.
Even more dramatic was my shift in eating schedule. New York City time was different from anywhere I had been before. I would often eat dinner late at night and have breakfast at 11:00 A.M. My body felt heavy and congested in the morning, and even though I got up at 7:30 A.M., I did not really wake up until hours later. Rather than the sense of vibrancy I felt in California, I experienced a sense of urgency—my body felt as if it needed either stimulation to work or sedation to recover from work.
Though I knew about good nutrition, the life I was leading took precedence over the foods I thought I should be eating. It was as if my job, my apartment, and my hectic schedule were the nutrition I needed most, and the food itself was secondary.
Environment is another important influence in our changing body and diet. People often report that upon moving to a new location they desire foods indigenous to that environment. One woman from South Carolina moved to Key West, Florida, and instantly developed an appetite for tropical fruit. Another woman moved to Sebastopol, California, one of the primary apple-producing regions in the country, and developed a keen taste for anything apple—juice, sauce, or pie—despite a previous distaste for apples.
When I moved to Southern California I began a love affair with avocados. I had tasted avocados only once before and found them unpalatable, yet something about San Diego made avocados taste good. They grew in backyards, in small orchards, and on trees lining residential streets. Avocados were in the air, and breathing where they were grown made me long for more of them.
When I moved to New York City my avocado affair ended and my pizza phase began. For five years in California I ate a “pizzaless” diet. Even to think about pizza made my stomach turn. The heat of Southern California plus my attraction to a diet centered around fruits and vegetables simply made pizza unappealing.
The moment I stepped onto Manhattan concrete, something inside me changed. No longer was I living in spacious, relaxed California. The New York City sidewalks were crowded and electric, and I felt as though something was needed to anchor me in the flood of activity. Pizza was that something. Certainly, this was not a deliberate, well-thought-out plan on my part. Yet somehow I found my way into a pizza place and then surprised myself by digesting four slices with ease. Despite a previous belief that pizza was bad for my body, it became a staple food for over a year.
Was my desire for avocados in San Diego or pizza in New York City psychological? Did these desires have a biological basis? Or were both components present? To each of these questions I would answer an emphatic yes.
An intimate connection exists between the food native to a region and the people living there. In the study of any ecosystem the organisms within a biological community are integrally linked to the available sources of food. It is not uncommon for animals to move into a new biological niche or territory—whether through population or environmental pressures—and adapt to new foods. Though human beings are not fully bound by the same natural laws as animals—we make psychological food choices more than biological ones—we still remain connected to our surroundings in tangible ways.
Eating the food unique to a given environment joins us to that environment. Just as an old house contains the memories and personalities of the generations that lived there, so too does food contain the essence of its environment. The heart, soul, and character of the land lie within its food.
Of course, pizza is not “indigenous” to New York City, yet for me it was the staple crop. Pizza meant Manhattan. I was not just eating a high-fat, high-protein food that gave me a sustained caloric burn and a grounded sensation in my midsection. I was swallowing up the Empire State Building, Greenwich Village, Lincoln Center, and the hidden dreams of every aspiring actor, writer, dancer, or entrepreneur. And in San Diego I was not just eating avocados, a food filled with vitamin A, unsaturated fats, and essential minerals, I was consuming the whole atmosphere—the warm desert winds, the tropical fruit trees, the jugglers in Balboa Park, and volleyball on the beach.
Diet, then, is a function of our environment. As our surroundings change, we change. Of course these dietary changes have a strong personal component: we are influenced by the people, the culture, and the excitement of a new environment. But are our biological needs entirely separate from our personal needs? Could there be a place where the two needs merge and nourish us more deeply than either by itself?
Closely related to environmental changes are seasonal ones. Seasonal cycles exert a profound influence on the needs of the body. For example, body metabolism and temperature normally increase simply by eating food, hence the old adage, Feed a cold and starve a fever. During the hot spring and summer months the sun’s energy warms the body, and we have less need to produce internal heat through the digestive process, so our appetite naturally decreases.
In addition, hot seasonal temperatures stimulate increased perspiration—the body’s mechanism for cooling itself—and hence our need for more fluid to replace the water lost through the skin. Many people recognize this as an increased thirst for cool liquids in the summertime and a corresponding decrease in the desire for hot foods. The environment graciously supports these changes in the body through the availability of fruits and vegetables in the warm seasons, the foods most naturally high in water content. Interestingly, even though metabolism increases in the warmer months, it is often slowed by extremely high temperatures. You may have had the experience of feeling energized in the spring but lethargic in the heat of the summer. Hence the custom of eating hot spicy foods in hot-weather climates such as curry in India or chili peppers in Mexico, which increases body metabolism and perspiration.
Conversely, metabolism decreases in the wintertime as body temperature mechanisms are challenged by the cold. Appetite naturally increases at this time as the body yearns for greater caloric intake to help keep its temperature within a normal range. Most people recognize this as a desire for hot foods and soups in the wintertime and an attraction to high-fat and high-protein foods such as meats, cheeses, casseroles, and fried foods. These foods are high in calories, take longer to digest than fruits and vegetables, and yield a sustained heat release in the body over a longer period of time.
Not only does the body call for more food in the winter months, it also calls for more weight, particularly body fat. Researchers have discovered that body weight is generally greatest when the mean January temperature is lowest. This extra body fat is an evolutionary adaptation to insulate us from the cold and provide an emergency source of caloric energy.
Age is another factor influencing our changing dietary needs. In the course of only a few years the perfect diet changes from umbilical-cord nourishment to breast milk to simple puréed food. Then the body longs for more complex foods to challenge the digestive system into full function and to meet the child’s growing nutritional needs. It is a miracle that within such a brief time the process of nourishment alters in so many profound ways.
The transformation of body and diet continues into adulthood. You may have noticed the huge amount of food teenagers consume or remember your own ravenous appetite in adolescence. The rate at which a teenage body grows and metabolizes demands a larger amount of food per pound of body weight relative to other age groups.
On the other hand, you may have noticed the small amounts of food many elderly people consume. Because of their decreased rate of metabolism, they need only a fraction of the calories required to maintain a similar size youth. The decrease in metabolism and physical output is why many elderly people can eat small amounts of food and gain weight. Other age-related changes in senior citizens include decreased taste sensation, decreased nutrient needs, and even a drop in the psychological desire for food.
Medical science has certainly focused on the unique nutritional needs of the young and the old, but the ages between twenty and fifty-five are generally clumped together in one homogeneous group. What are the differences in nutritional requirements between a twenty- and a thirty-year-old? Between a forty- and a fifty-year-old? These distinctions are subtle, yet much remains to be uncovered in this area. In the meantime, suffice it to say that age changes lead to body changes, which lead to diet changes.
Health is the last key factor influencing diet. Many of us are accustomed to adjusting our diet during common illnesses such as colds, flu, and fever, and during undiagnosed health conditions such as low energy episodes, digestive complaints, or periods of low immunity. The foods we choose may be unusually bland or spicy, appetite may fluctuate, or we may reach for favorite food remedies—teas, soups, fruits, toast, and so on.
For some people health considerations alter diet for life. Special diets are crucial during chronic illnesses such as heart disease, liver disease, diabetes, and ulcers. Each of these medical conditions has a corresponding therapeutic diet with specific food guidelines to support or perhaps even heal the body.
For a diabetic the perfect diet is low in sugar and high in complex carbohydrates. For those with gout, a low-meat, low-protein diet proves best, while heart disease patients follow a low-fat, high-fiber regime. Other special body states such as pregnancy, lactation, and menstruation also have unique nutritional considerations.
Can you see how the five key factors—life-style, environment, season, age, and health—interact to create a ceaselessly changing diet? Do you still think it’s possible for a single, perfect diet to exist?
The body symbolizes that which is changing, ephemeral, and beyond control. Though we seldom ponder our destination, all sentient beings intuit the body’s ultimate fate—death and disintegration. Because we fear the uncertain nature of death and the uncertain nature of life, we attempt to control the unknown by controlling the body.
By following a diet we believe to be perfect, we are pretending that the body never changes and that we can therefore avoid the unknown. Have you noticed how often we do not act upon a decision until we are certain of the outcome? Believing in a perfect diet means we need not worry about nutritional changes that might otherwise perplex us. Our cookbook tells us what to do and keeps our diet free from any surprises. And yet, when the body undergoes inevitable change and yearns for foods outside this “perfect system,” we experience great conflict. We believe something is wrong with us because we cannot hold to our imagined standards of perfection.
The fear of shifting to new foods as the body’s needs fluctuate is symbolic of our fear of change—change in our job, health, family, relationships, or inner consciousness. Life moves from the known to the unknown. Whether it is discoveries in science, the outcome of a baseball game, tomorrow’s weather, or next minute’s mood, we can never be certain of what is next. Even if we could know something for sure, say, that we will have a telephone conversation with a friend at an agreed time, we still do not know how we will react in that instant. This moment is known; the next moment is unknown.
Believing that a perfect diet will protect us from the unknown changes in the body is like buying an insurance policy from an imaginary company; it never pays off. Rather than search for the ideal way to eat, allow yourself to find the answers by dropping the questions altogether, at least for a little while. I am deliberately staying away from nutritional advice and guidelines for now because you can find nutritional information almost anywhere. Nutritional wisdom, though, is rare.
The claims for optimum foods and nutrients have been greatly overstated in the printed media. I am overstating another approach—not the science of eating but the consciousness of eating, the awareness necessary to examine the basis of our scientific beliefs, nutritional biases, and emotional relationship with eating. For, in the long run, understanding the mind of the eater may well prove to be as nourishing an act as understanding the foods that are best to eat.
1Although there are cells in the body such as certain types of brain cells that may last a lifetime and never regenerate to their original functional capacity when destroyed, the atoms in the cells are nevertheless continually replaced.