While our national "nutrition consciousness" has expanded to the extent that many Americans do supplement their diets with vitamins these days, there's probably no point on which people's beliefs differ as much as they do about good eating habits and the values (or hazards) of various types of food. And—since it's not considered good scientific ethics to feed a possibly dangerous substance to men and women in order to test its toxicity—really conclusive nutrition studies (those done on human beings) are as rare as hens' teeth
Another element that clouds the whole nutrition issue is the "placebo phenomenon." You see, the mind is more powerful in shaping the effects of a food or drug than most folks think. In one recent study, for example, volunteers were given a drug that usually produces a violent nausea and vomiting, but the men and women were told the substance would relax and soothe their stomachs. Sure enough, the human "guinea pigs" experienced no queasiness, and internal measurements showed that their stomachs actually became more relaxed after the medication was administered! So, if you believe that a food is good for you, you can most likely eat that food and feel better regardless of what the substance may actually be doing to your body chemistry.
A third factor that adds to today's nutritional confusion is that different individuals can have very different dietary needs. In fact, if the size of our facial features varied as much as the concentration of certain enzymes in our bodies, some of us would have noses the size of BB's, while others would have 20-foot snouts'
Sweet, Salty, and Fat Villains
That's the bad news. Now here's the good. In spite of all the raging controversies in the field, there are four basic nutritional guidelines which seem to hold true for nearly everyone and upon which the experts do agree:  Eat less fat,  eat less refined sugar,  eat less salt, and  avoid suspect food additives, especially nitrates and saccharin.
Many people, if asked to name the most harmful component in their diet, would probably say sugar, but—for almost all North Americans—the worst dietary villain is fat. The body's need for this substance is very small, and easily supplied by a diet that includes a variety of whole grains. Most Americans, however, eat over 40% of their calories in the form of fat—more than 10 times as much of the substance as humans really need—even though the association between high-fat diets and heart diseases (which cause more deaths in this country than all other illnesses combined) is well-known.
This largely unnecessary food accumulates in hard, white, fatty deposits on the inner walls of our arteries. These atherosclerotic plaques, as they're called, can begin to form in childhood or early adulthood and may grow until they block the passageways through which the blood must flow. Eventually, the narrowing of the coronary arteries increases the risk of a complete cutoff of blood to part of the heart's muscle. The result of such a stoppage is a heart attack. (There's also good evidence to indicate that a high-fat diet increases one's risk of both breast and bowel cancer.)
There are two sources of fat in our diets: the obvious and the hidden. The obvious sources include fatty meats, oil, vegetable shortening, cream, butter, lard, and greasy fried foods. But many items that one doesn't ordinarily think of as "fatty"—such as peanut butter, eggs, pizza, avocados, soybeans, nuts, seeds, many baked goods, and all dairy products except those made from skim milk—are also significant sources of the potentially dangerous substance. The obvious fats should be avoided when possible, and the others should be eaten only in moderation.
Since salt, on the other hand, is associated with increased blood pressure, persons with hypertension (high blood pressure, or HBP) should entirely remove the saltshakers from their tables. And folks who have relatives with HBP—since the disease runs in some families—should also try to decrease their salt consumption. Likewise, people with diabetes—and those whose families have a history of diabetes—should be especially careful not to overdo their sugar intake.
Better Health Costs Less
Naturally, when you change your diet to exclude foods that are high in fat, sugar, salt, and additives—and to incorporate more whole grains, beans, and vegetables—be sure to make the switch gradually. If there are some "junk foods" you really love, just substitute nutritious foods of similar taste or texture: banana chips for potato chips, fruit juice for milk shakes, baked potatoes for french fries, and fresh fruit whipped up in the blender for jams and jellies.
In addition to providing a better nutritional balance, eating foods closer to their natural state will sometimes result in lower food bills. In general, processed foods are both higher in the big bad three (fat, sugar, and salt) and more expensive than their fresh counterparts. For example, you can sometimes buy potatoes for as little as a dime a pound, while a pound of fast food trench fries would cost about $2.00.
Read All About It
In order to provide more information on good eating than it would be possible to include on this page, I've compiled a list of resources you can use to help cut the cost of a healthful diet and at the same time make you feel your best.
The "New American Eating Guide" is a handy, four-color poster that divides everyday foods into three categories: foods to eat anytime, those to eat in moderation, and some to sample now and then. (I'd like to see this valuable tool for nutritious eating taped to every refrigerator door.)
Laurel's Kitchen: A Handbook for Vegetarian Cookery and Nutrition by Laurel Robertson, Carol Flinders, and Bronwen Godfrey combines a fine cookbook with a 150-page introduction to the essentials of nutrition, plus one of the most easily used nutrition tables I've seen.
Diet and Nutrition by R.M. Ballentine, M.D., a wholistic "I-Ching of nutrition books," offers a comprehensive review of scientific nutritional research and reports both sides of many controversial issues: Dr. Ballentine presents the evidence and lets you come to your own conclusions.
"Which Fast Foods Are Best?" (an article published in Consumer Reports, September 1979) concludes that fast foods are nutritionally acceptable if consumed infrequently and as only part of a well-balanced diet. It further suggests that regular fast-food customers skip the shakes and fries, and points out a heartening development: Some fast-food chains are adding salad bars.