Just think of the poor egg. In the 1950s, no self-respecting mother--including mine!--would have dreamed of sending her children to school without an egg for breakfast. But this low-cost, readily available source of protein lost favor in the 1970s because of the 212 milligrams of dietary cholesterol that it packs per yolk. (The average daily intake of dietary cholesterol recommended by the National Heart Lung and Blood Institute is 220 to 260 milligrams for women and 360 milligrams for men.)
Egg consumption went into a slow tailspin, going from its heyday of 402 eggs consumed per person each year in 1945 to an all-time low of 233 eggs per person in 1991, according to the American Egg Board.
Then guess what? Studies began to expose the good ingredients lurking inside the shell. The egg white is rich in protein, low in calories. Even the yolk didn't look quite so bad when scientists figured out that dietary fat was probably a bigger player in raising blood cholesterol levels than the cholesterol in the egg.
Along the way, the American Heart Assn. eased its recommendations to limit our egg intake. Then, adding to the information, along came the marketers: The American Egg Board launched the "Incredible, Edible Egg" campaign to alert consumers to the newfound benefits of its product (and to downplay the disadvantages); at the same time, some farmers even began feeding their chickens fish meal to boost their eggs' omega-3 fatty acids, a substance that appears to reduce the risk of heart disease. Suddenly, eggs were no longer nutritional outcasts; consumers, as usual, could be forgiven for feeling nutritionally out of it.
Almost as important as our demonization of certain foods is the tendency to glorify others, usually on the basis of oversimplified interpretations of scientific evidence. The best example: fat-free foods that were elevated to nutritional sainthood when researchers in the 1980s began linking fat to increased cholesterol levels and the risk of heart disease and cancer. The 1995 Dietary Guidelines for Americans reinforced that message by advising us to eat a low-fat diet.
Spurred by our demand, the food industry provided a multitude of low-fat and fat-free products, from cakes and cookies to whipped topping, frozen yogurt and "Guiltless Gourmet" snacks.
Trouble was that too many Americans saw the "fat free" label as a license to overeat. Rather than savoring one high-fat cookie, why not scarf down a whole box of fat-free morsels? But, of course, fat-free food is not calorie-free, and the results were disastrous: When we switched to low-fat foods in the 1980s and '90s, the percentage of fat in the average American diet declined slightly, according to the USDA. But because we were actually eating more calories per day, the amount of absolute fat consumed rose. And guess what? So did obesity rates.
Other misguided efforts led to the nearly monastic suggestion of using no oil or other kind of fat on salads and vegetables. Vinegar or a touch of lemon was preferred. Not only did this practice rob us of taste, but it made absorption of fat-soluble vitamins--the powerful antioxidants such as vitamins A and E--much more difficult. (While the final chapter of the antioxidant story has yet to be written, I've read enough to be sure to add a little oil to my salads.)
Based on these and other scientific findings, the latest draft of the dietary guidelines urges Americans to be less fat-phobic and more fat-savvy. What that means is that it's OK to drizzle a little olive, walnut, canola or any of the other so-called "good" oils on your salad. Just don't go overboard. Better to eat only minimal amounts of fried chicken, french fries and high-calorie baked goods that pack a lot of saturated fat and trans fatty acids--now recognized as the most dangerous kinds of fat.
Putting What We Eat in Medical Terms
Perhaps where we have gone wrong the most is in medicalizing eating. Diet books offer foods and recipes as a weapon against disease. The grocery store shelves feature bold new designer foods that are nearly potent enough to come with their own prescription labels. That's not just fresh-squeezed juice; it's calcium-fortified orange juice for strong bones. Don't spread butter on your toast; try the cholesterol-lowering margarine instead. Those chicken breasts? They're sauteed in polyunsaturated oil and served with folic-acid-fortified pasta. And those aren't just tomatoes on our salad--they're lycopene-containing vehicles topped more and more often by a vitamin E-fortified salad dressing.
Cookbook authors have jumped on the medicalization bandwagon, producing recipes that pander to many medical conditions. Among the recent volumes that have crossed my desk are "The Menopause Cookbook," "Cook Your Way to the Life You Want," "The New Eating Right for a Bad Gut" and "God's Diet," a book for a spiritually based weight-loss program that focuses only on food God made.