Miércoles 18 de Junio de 2008, Ip nº 234

How I learned to [heart] breakfast (or at least what to eat for it)
Por Amanda Fortini

As meals go, breakfast is something of a celebrity. It is one of the most studied, analyzed, parsed, discussed, and advised-about subjects of nutritional science. Never more so than today, as doctors, and nutritionists, and countless articles and academic papers prescribe breakfast as both prophylactic and cure-all: The morning meal is said to stoke metabolism, stop late-night grazing, thwart obesity, reduce diabetes risk, improve nutritional intake, sharpen concentration—even increase longevity. In March, a new study more conclusively linked breakfast with body-mass index, with weight increasing as the frequency of breakfast consumption decreased. Breakfast, it seems, is highly influential: the power broker of repasts.

Yet despite all the fussing over and fetishizing of breakfast, most of us have only the vaguest notion of what we should be ingesting. Each new study of breakfast seems to contradict the last. Are eggs advisable, or will they raise one’s cholesterol? Is a meal of toast anemic or adequate? What is a whole grain, anyway? And most important, are we really making ourselves fatter, hungrier, dumber, shorter-lived, slow metabolizers by not eating a so-called proper breakfast? As the experts continue to debate, most of us shrug and make choices not out of any real knowledge but for lack of time. If we don’t slurp down a bowl of cereal at home, or succumb to the buxom muffin beckoning from the glass case at the deli, then an enormous caffeinated drink with a hyphenated name becomes our de facto morning meal.

Or we have nothing at all. National survey data cited by the Breakfast Research Institute indicates that between 1965 and 1991, the number of adults who regularly skip breakfast increased from 14 to 25 percent. The attrition of breakfast-eaters is understandable. After all, what’s to love about breakfast? The first meal of the day tends not to be celebratory or communal; unless we’re talking about brunch, breakfast’s fashionably late cousin, the morning meal is usually a solitary, functional affair. “Breakfast is the proper meal, the one that’s usually prepared by oneself and eaten alone,” David Heber, director of the UCLA Center for Human Nutrition, told me. “It’s not as much fun as going out with friends for lunch or dinner. It’s a chore. Breakfast is a meal people are ready to dump.”

The multifarious reasons people cite for dumping breakfast shed some light on the psychology of the meal. Some simply don’t like to eat in the morning; a handful of friends, none of them pregnant, tell me that even the smell of food before eleven makes them nauseated. Chronic dieters pass on breakfast with an eye toward shaving a few hundred calories off their day. Others can’t seem to squeeze in a meal amid the chaos of their morning: the dog to walk, the children to dress, the in-box fires to extinguish, the enervating commute. Still others, and I count myself among this crowd, sometimes abstain because the received wisdom about breakfast seems possibly spurious—one of those persistent nutrition myths, like the notion that you need eight to ten glasses of water per day or that celery has negative calories: If breakfast is supposed to curb your appetite, then why, shortly after partaking, am I ravenous, unable to focus on anything but foraging for more food, hungrier than when I don’t eat anything?

I am not the only breakfast skeptic out there (though this is, to be sure, a decidedly less populous camp). “I think it’s a nonissue for adults,” said Marion Nestle, professor of nutrition and food studies at New York University and a breakfast skipper herself. “I think people should eat when they’re hungry. Some people are really hungry in the morning and some are not.” In her book What to Eat, she writes, “I am well aware that everyone says breakfast is the most important meal of the day, but I am not convinced. What you eat—and how much—matters more to your health than when you eat.”

But since so many researchers argue that breakfast does matter, I began to investigate. How, exactly, are we harming ourselves by failing to eat breakfast? The simplified answer is that it depends on how young you are. Even Nestle concedes that there is strong evidence that children who skip breakfast do not fare as well academically or physically as those who eat it. A study conducted by researchers at Tufts University found that children who consumed a breakfast of Quaker instant oatmeal displayed better spatial memory and an increased ability to stay on task (what the study called “vigilance attention”) when performing a battery of cognitive tests than children who ate Cap’n Crunch, and, perhaps surprisingly, those who ate the sweetened cereal performed better than those who ate nothing. Another study, this one by researchers at the University of Reading, found that adolescents fed a sugary drink in the morning will subsequently display all the mental agility of a 70-year-old. It’s not much of a leap to assume that an adult who skips breakfast will have the same difficulty concentrating at work as a kid sitting in a classroom—hunger is distracting whatever your age—but distracted office workers have not been a major concern for breakfast researchers.

Researchers are interested in breakfast because they are interested in obesity, and they suspect that skipping the former plays a role in fostering the latter. “The frequency of eating breakfast has declined over the past several decades, during which time the obesity epidemic has also unfolded,” write researchers Maureen T. Timlin and Mark A. Pereira in an excellent meta-analysis of all the scientific literature on breakfast to date, published in the June 2007 issue of Nutrition Reviews. Timlin and Pereira—the pair appear to be the Boswells of breakfast—also conducted the study about breakfast and body-mass index (BMI) published in Pediatrics in March. They tracked 2,216 Minnesota adolescents for five years, and found that subjects who skipped breakfast were consistently heavier than those who did not.

The relationship appears to hold for adults as well. A 2003 study published in the American Journal of Epidemiology concluded that subjects who habitually skipped breakfast (at least 75 percent of the time) had a four and a half times higher risk of obesity than those who habitually consumed it. (Those who missed breakfast even once during the study had an increased risk of obesity.) And of the 5,000-plus members of the National Weight Control Registry—registrants have lost an average of 66 pounds and have kept it off for more than five years—78 percent claim to be regular breakfast eaters.

But breakfast-eating and weight-management may not be connected in the way that we think: Despite what women’s magazines, and pop health magazines, and legions of mothers say, the mere act of consuming breakfast does not miraculously speed up one’s metabolism. In fact, it’s hard to pinpoint exactly why eating breakfast tends to coincide with healthier weight. It may be that eating breakfast simply creates a feeling of satiety, which prevents trips to the vending machine or the drive-through in the afternoon or evening. (Eating at regular intervals maintains insulin and blood-sugar levels, preventing the peaks and valleys that cause voracity.) The American Journal of Epidemiology study found that adults consumed more calories on the days they eschewed a morning meal.

The real problem, from a researcher’s point of view, is that breakfast consumption is a habit that tends to occur along with a constellation of other healthy behaviors—like exercising, not smoking, and maintaining a healthy diet—that may confound or influence the effect of breakfast on obesity. (Unhealthy behaviors, too, tend to stick together: Fewer than 5 percent of smokers eat breakfast daily.) In at least one study, when confounding variables were accounted for, the relationship between breakfast and body-mass index was not significant. The eating of breakfast was only an ancillary factor, one salubrious practice among several that contributed to slimness. Breakfasting and forgoing the gym will probably do little to reduce or control one’s weight. In the Pediatrics study, for example, it seemed surprising that the breakfast eaters often had a higher daily caloric intake and yet also a lower BMI than their breakfast-skipping peers, but when I asked Pereira what explained this finding—had eating a morning meal somehow increased the subjects’ metabolism?—he emphasized that the eaters were exercisers as well.

This is all to say that it is not yet clear to researchers whether the relationship between breakfast and obesity is causal (i.e., breakfast consumption directly influences weight) or merely associational. Breakfast may play a supporting role in weight management, rather than a starring one. Few prospective studies (in which breakfast-eating subjects are followed over a period of time) or clinical trials (in which breakfast eating is tested as an interventional therapy, as a drug might be) have been done. This is why the Pediatrics study, conducted prospectively over the course of five years, was a significant contribution to the field of breakfast studies: We can observe the correlation between breakfast consumption and BMI over time, which approximates cause and effect.

If mere consumption is not itself transformative, the question remains: What are we to eat? People have been fretting about what constitutes an ideal breakfast since at least the 1800s. Sylvester Graham, of cracker fame, promoted his high-fiber, additive-free wheat flour as a remedy for the dyspepsia epidemic of the time, which he felt was caused by the meat-centric, multicourse American breakfast: an extravaganza of pancakes, biscuits, eggs, bacon, fried ham, salt pork, and potatoes. (Such hearty fare had been fuel for the farmer but was fattening to the more sedentary industrialist.) As Scott Bruce and Bill Crawford write in Cerealizing America, the ascetic Graham believed that “meat eating inflamed the ‘baser properties,’ ” leading to masturbation—what he called “the vice”—and that “tea drinking led to delirium tremens.” Sixty years later, John Harvey Kellogg, who breakfasted on graham crackers and apples himself, also peddled grains, in the form of the first flake cereal, as a vegetarian cure for digestive trouble. You might say that breakfast has a long history of having the fun drained out of it.

The warring of the diet factions continues today in a slightly more scientific fashion. A 2003 paper published in the Journal of the American College of Nutrition claimed that individuals who consumed ready-to-eat cereal, cooked cereal, or, oddly, “quick breads”—waffles, pancakes, pastries, and the like—had lower BMIs than those who ate meat and eggs or abstained from breakfast entirely. But a 2007 study found the opposite: Obese women who ate two eggs for breakfast daily for eight weeks lost 65 percent more weight than their bagel-fed counterparts. Like most prescriptive studies, however, these two must be taken with a grain of salt (or, in the case of the cereal study, a few granules of sugar): Kellogg funded the former; the American Egg Board funded the latter. Among those in the field of nutrition research, it is widely acknowledged that, for a variety of reasons ranging from flawed study design to buried negative results, industry-funded studies tend to find industry-favorable results. For instance: The Tufts study that found that Quaker instant oatmeal (and, to a lesser degree, Cap’n Crunch) improved cognitive performance was funded by Quaker, the maker of both products.

The studies and advice grow ever more specific and contradictory: If your aim is to optimize attention span and memory—especially in children—then, according to one study, the best breakfast is ham and hard cheese on whole-grain bread. If you want to prevent heart disease (and who doesn’t?), try whole-grain cereal; one bowl per day is associated with a 28 percent lower risk of heart failure. If you’re a woman hoping to conceive a boy, then, according to a recent study from the University of Exeter, you should increase your breakfast consumption by approximately 400 calories daily. (Women with the highest caloric intake had boys 56 percent of the time, compared with 45 percent with the lowest caloric intake.) It’s enough to make one feel inclined to take refuge in Vonnegut’s breakfast of champions: a morning martini.

And yet, even as they disagree on the specifics, the majority of researchers seem to agree that what we put into our bodies in the morning is a critical decision. Because it occurs after eight, ten, or even twelve hours of sleep, the breakfasting moment is physiologically unique. “The nature of the food we eat affects hormones in profound ways for many hours after a meal, and that’s more important after breakfast,” said Dr. David Ludwig, associate professor of pediatrics at Harvard Medical School and author of Ending the Food Fight. “We’ve been fasting and stress hormones are elevated and we’re insulin-resistant, so we can use the properties of food at this time to our benefit or our detriment.” A fasting body is particularly sensitive to, say, a sugary, refined-starch, low-fiber muffin; blood sugar will soar and then plummet, leaving you famished once again.

What’s preferable, according to Ludwig, is to choose breakfast foods with a low glycemic index (GI). The term refers to the rate at which glucose is absorbed from carbohydrates—or, put another way, how rapidly carbohydrates affect blood sugar. This is important because controlling insulin and blood-glucose levels in turn controls appetite and, ultimately, weight. In a 1999 study led by Ludwig, twelve obese teenage boys were fed at various occasions high-GI (“instant oatmeal”), medium-GI (“steel-cut oats”), and low-GI (“a vegetable omelette and fruit”) breakfasts and lunches, and then were allowed to consume all the food they wanted for the rest of the day. The high-GI cohort, in a state of crashing blood sugar and surging adrenaline induced by the instant oatmeal, devoured 500 to 600 extra calories. (This phenomenon likely explains that postprandial ravenousness I often experience—my morning mainstays, toaster waffles and quick-cooking oats, rank fairly high on the GI list.) Low-glycemic foods may even help breakfasters achieve that dietary holy grail: speeding up metabolism. In another study, subjects kept on such a diet saw their metabolic rate shift slightly to burn approximately 80 more calories per day—not a lot, but every little bit helps.

How to tell if a food has a low glycemic index? A quick rule of thumb: The more processed the food, the higher its GI; the higher a food’s fiber content, the lower its GI. Breakfast, in other words, should be a high-fiber affair. This means vegetables and fruits (but not juices—the fiber is in the pulp and skin) and whole grains. For the record, a whole grain is an intact, unrefined grain that retains the bran and germ, its nutrient- and fiber-rich components.

Eggs too may help to control blood sugar (protein stimulates the release of glucagon, a hormone that counterbalances insulin), but don’t defect to the Atkins camp just yet. Eggs are also high in cholesterol. Many doctors, noting that sensitivity to dietary cholesterol varies, advise limiting eggs to several per week.

So what, then, to eat? The path of bread crumbs—or cereal flakes—through the thicket of breakfast suggestions is this: Breakfast is not dessert. Most muffins and bagels are out, as are those breakfast bars with the creepy strip of ersatz milk, and the many cereals that claim to be “whole grain” but are in fact sugary and fiberless. Out too are my beloved toaster waffles, unless I find a version containing the recommended five grams of fiber per serving. What remains are the foods that we probably should have been eating all along: unprocessed, low-GI, fiber-rich foods like fruits, vegetables (in omelettes if nowhere else), oatmeal (slow-cooking or steel-cut rather than instant), whole-grain breads and cereals (that are also high in fiber and low in sugar), protein in the form of low-fat dairy, and eggs in moderation. Nothing too exciting, but then, breakfast is all business. If you’re looking for thrills, try dinner.

  Junio de 2008. New York Magazine.