Not all the nutrients and other substances that contribute to good health have been identified, so eating a wide assortment of healthy whole foods like fruits and vegetables helps ensure that you get all of the health-promoting benefits that foods can offer. If your diet, day after day, consists of the same half dozen foods, it could fall short. In addition, varying your food choices will limit your exposure to any pesticides or toxic substances that might be present in particular foods.
These foods—notably vegetables, fruits, legumes, and whole grains—should supply about 20 to 35 grams of dietary fiber a day, depending on your calorie needs. (Aim for 14 grams of fiber for every 1,000 calories, as advised by the Dietary Guidelines for Americans.) Fiber slows the absorption of carbohydrates, so they have less effect on insulin and blood sugar, and it provides other health benefits. Try to fill three-quarters of your plate with produce, legumes, and whole grains—leaving only one-quarter for meat, poultry, or other protein sources.
For a 2,000-calorie daily diet, aim for 2½ cups of vegetables and 2 cups of fruit a day. If you consume more calories, aim for more produce; if you consume fewer calories, you can eat less. Include green, orange, red, blue/purple, and yellow vegetables and fruits. In addition to the fiber, the nutrients and phytochemicals in these foods may help protect against certain types of cancer and other diseases. Legumes, rich in fiber, can count as vegetables (though they have more calories than most vegetables). For more fiber, choose whole fruits over juice.
These include soda, candy, white bread, regular pasta, and many snack foods and baked goods. A high intake of added sugar increases inflammation and insulin resistance, increasing the risk of diabetes, cardiovascular disease, and other disorders—and it supplies “empty” calories that contribute to weight gain. Refined grain products have little dietary fiber and have been stripped of many nutrients; a high intake can cause many of the same health problems as added sugar.
At least half your grains should be whole grains, such as whole wheat, oats, barley, or brown rice. Whole grains retain the bran and germ and thus all (or nearly all) of the nutrients and fiber of the grain. One sure way of finding whole grains is to look for a product labeled “100% whole wheat” or “100%" of some other whole grain. You can also look for a whole grain listed as the first ingredient, though there still may be lots of refined wheat in the product. Another option is to look for the voluntary “Whole Grain Stamp” from the Whole Grains Council. Or try this tip: Look for less than a 10-to-1 ratio of “total carbohydrates” to “fiber” on the nutrition label.
Food processing isn’t always a bad thing: Cooking and preparing raw ingredients at home is also processing them. But the word “processed” is almost always reserved for commercial foods, usually packaged. Highly processed foods are industrially formulated mixtures that are no longer recognizable as their original plant or animal sources—everything from hot dogs and margarine to ice cream, candy, and many packaged snack foods. Such foods, which supply more than half the daily calories in most U.S. households, lack key nutrients and fiber and are high in sugars and sodium.
The saturated fats in animal foods generally boost levels of LDL (“bad”) cholesterol and have other adverse effects. To limit your intake, choose lean meats, skinless poultry, and nonfat or low-fat dairy products. It’s also a good idea to replace saturated fats with unsaturated fats (see next slide). Keep in mind, though, that not all saturated fats are bad for you; those in chocolate, milk, and cheese, for example, are more neutral in their effect on blood cholesterol. Trans fats from partially hydrogenated oils are even worse than saturated fats, but FDA regulations have now nearly phased them out of the food supply.
As found in nuts, seeds, fish, avocados, and plant oils. You should consume these high-fat foods in place of other high-calorie foods; otherwise, you’ll be adding excess calories to your diet. For instance, substitute olive or canola oil for butter, and nuts for chips. Fatty fish may reduce the risk of heart disease and have other benefits, attributed at least in part to their omega-3 polyunsaturated fats.
The latest Dietary Guidelines no longer give a daily cap for dietary cholesterol (previously it was 300 milligrams), because there’s abundant evidence that dietary cholesterol (found only in animal foods) has little if any effect on most people's blood cholesterol. Rather, saturated fats raise LDL (“bad”) cholesterol more than dietary cholesterol does. But don't go overboard with cholesterol-rich foods, since many of them are also high in saturated fats. And if you have cardiovascular disease or diabetes, ask your doctor if you should limit dietary cholesterol.
Excess sodium, found in many processed foods and restaurant meals, raises blood pressure in some people and can have other adverse effects. The Dietary Guidelines recommend a limit of 2,300 milligrams a day for the general population; people with hypertension or prehypertension can benefit from a further reduction to 1,500 milligrams per day. As you cut back on sodium, eat more potassium-rich foods, which help lower blood pressure. These include citrus fruits, bananas, beans, avocados, some fish, and dairy products.
Supplements can't substitute for a healthy diet, which supplies other potentially beneficial compounds besides vitamins and minerals. Foods also provide the synergy that many nutrients require to be efficiently used in the body. Still, for many people a basic multivitamin/mineral pill can provide some of the nutrients they may fall short on. Certain people may also need supplements of folic acid, vitamin B12, calcium, and vitamin D (see next slide).
These support bone health and have other possible benefits. Dairy products are the best sources of calcium, but you can also get it from fortified foods as well as canned salmon, sardines, dark leafy greens, and most tofu. If you can’t get the recommended 1,000 to 1,200 milligrams a day from food, take a calcium supplement. It’s hard to consume enough vitamin D from foods (the RDA is 600 to 800 IU a day, though other experts advise more). Thus, many people—especially those who are over 60, live at northern latitudes, or have darker skin—should consider taking a supplement.
That means one drink a day for women, two a day for men. People over 65 should drink even less. A drink is defined as 12 ounces of beer, 5 ounces of wine, or 1½ ounces of 80-proof spirits. While alcohol has potential heart benefits, it poses a variety of health risks, especially in excess amounts. And some people shouldn't drink at all, including pregnant women and those taking medications that interact with alcohol. People with liver disease, high trigylcerides, sleep apnea, and certain other conditions should ask their doctors about the advisability of drinking.
For many people, food is a chore, a challenge, even a source of dread, as they try to overcome poor eating habits. But eating should be a joy and a centerpiece of family life. Many cultures around the world emphasize the enjoyment of food, which includes cooking and eating with others, as an integral component of good health. The latest Dietary Guidelines say that eating healthfully involves “enjoying food and celebrating cultural and personal traditions through food.” According to some research, shared mealtimes, especially during childhood, may help protect against nutrition-related health problems as well as increase prosocial behavior in adulthood.