Evolving one’s diet away from fats begins with reading food labels. The nutritional label recently introduced by the Food and Drug Administration states the percentage of calories from fat in one serving of the item.

As a general rule, select foods that contain no more than 20 percent of calories from fat per serving. But beware: sometimes the serving size represents less than what you’re likely to eat, meaning that its actual fat content is higher. And don’t be fooled by the Daily Value (DV) listing. The DV tells you how much of a day’s worth of fat, cholesterol, sodium, etc., the food provides, based on a hypothetical 2,000-calorie-a-day diet. DV ratings are in bold on the new nutrition labels, but they often understate the amount of fat an item contains. A snack food might have a fat DV of 25 percent, which might seem acceptable to the unsuspecting consumer, but still contain 75 percent of calories (or more) from fat.

As far as unlabeled foods are concerned, here are some guidelines:

Fruits, vegetables, and beans. They’re low in fat and high in carbohydrates, just the ticket for a healthy diet. Just don’t destroy them by smothering them in high-fat butter, margarine, or cream.

Pastas and grains. Here’s another food group that’s low in fat and high in carbohydrates. Eat more of them, as long as you’re careful about what you add to them.

Breads. Eat as much as you want, but beware of crackers, muffins, biscuits, croissants, and other bread treats, which are high in fat. In addition, be careful about spreads. Low-fat choices include: jellies, jams, preserves, mashed bananas, bean dip, and nonfat yogurt, cream cheese, or cottage cheese. Butter, margarine, peanut butter, and cheeses are high in fat.

Nuts and seeds. Nuts and seeds are high in fat. If you eat them by the handful, you can consume a great deal of fat. Use nuts and seeds sparingly to top fruits, vegetables, beans, pastas or grains. Or substitute Grape Nuts cereal (completely fat-free), or toasted bread crumbs, oats, or cornmeal.

Eggs. Use commercial egg substitutes in cooking and baking. For scrambled eggs or omelets, mix one real egg into a bowl containing mashed tofu or two or three eggs’ worth of substitute.

Meats. Of all the red meats, only venison contains fewer than 20 percent of calories from fat. Beef, veal, pork, lamb, duck, sausages, and luncheon meats are all high in fat. But you don’t have to eliminate them from your diet. Simply change how you use them. Instead of building your meals around them, choose recipes that use small amounts of meat to flavor dishes based on vegetables, beans, or grains, the way Asian cuisines do. If you love BLTs, you can still have them, but instead of four strips of bacon and one slice each of lettuce and tomato, pile on the L and T, and crumble one strip of bacon over them. And if you love burgers, select leans cuts — the leanest is fat-trimmed top round. Ask your butcher or supermarket to grind it for you. Then thin your burgers by adding oatmeal and grated carrots. When you pan-fry ground beef for spaghetti sauce, brown it first, then place it in a colander and rinse it thoroughly with hot water. This removes a great deal of the fat.

Chicken. Skinless white-meat chicken breasts are low in fat, and can be used in a virtually limitless number of low-fat recipes. But watch out: chicken skin is high in fat. If you eat it, you lose chicken’s benefits. Strip the skin before you cook chicken. The meat can absorb a great deal of skin fat during cooking. Dark meat chicken parts (thighs and drumsticks) are also high in fat. You can still eat dark meat. Just use it sparingly in recipes whose main ingredients are vegetables, beans, or grains. Also beware of chicken hot dogs. They’re often as high in fat as their pork or beef counterparts. Chicken hot dogs are mostly skin and dark meat. Finally, be careful how you cook your skinless chicken breasts. Fried or batter-dipped, they drip with fat. Ditto for butter- or cream-based sauces.

Turkey. It’s not just for Thanksgiving anymore. Ounce for ounce, a skinless white-meat turkey breast is even lower in fat than a chicken breast. These days, supermarkets sell it whole, sliced, or in cutlets. If you pound turkey cutlets and cook them like veal, and it’s hard to tell the difference. But be careful — turkey has the same caveats as chicken: trim the skin. Cook it skinless. Steer clear of dark-meat turkey, turkey franks, ground turkey, frying, and high-fat sauces.

Fish and seafood. Most fish and seafood are low in fat: cod, flounder, lobster, scallops, shrimp, snapper, and sole. But several fish are fairly high in fat: herring, mackerel, and salmon. To keep your fish low in fat, bake, broil, poach, or grill it, or pan-fry it in wine. Don’t fry it in butter or margarine or cover it with butter- or cream-based sauces. If you enjoy high-fat fish, use small portions, and combine them with vegetables, beans, and grains. Canned tuna comes packed in either water or high-fat oil. Choose water.

Butter, margarine, and oils. They’re all 100 percent fat. Butter is the most harmful because it’s the highest in saturated fat, which raises cholesterol, and contributes to heart disease. But margarine contains trans-fatty acids, which also increase risk of heart disease. Olive oil, a monounsaturated fat, does not increase risk of heart disease, nor, according to some studies, the risk of breast or colon cancer. But olive oil is still 100 percent fat. Use it sparingly. One good way is to reduce the amount recipes call for. If a recipe suggests 2 tablespoons of olive oil, try one or less. Or substitute vegetable broth or sherry. Or try an oil spray. Most people who cook with sprays, available at supermarkets, use less oil than they would if they simply poured liquid oil into their pans. One easy way to trim the fat is to use fat-free dressings on salads. Pritikin and other brands are available at most supermarkets. Or try vinegar or lemon juice with just a splash of oil.

“Low-fat” prepared foods. The dishes sold by some weight-control businesses and other similar programs claim to be low in fat. They are lower than the typical American diet, but most still derive more than 20 percent of their calories from fat. They are not low enough in fat to significantly reduce risk of the fat-related medical conditions. In addition, they use small portion size to reduce the total number of calories, so people who eat them often feel unsatisfied and risk bingeing on high-fat items.

The new nonfat foods. If reading this section has left you scratching your head wondering what’s left to eat, cheer up! Increasing consumer demand for nonfat items has filled supermarket shelves with all sorts of seemingly sinful, yet fat-free foods. Do you love cream cheese? Now there’s fat-free cream cheese made from skim milk. Does the word “dessert” make you salivate for ice cream? Try nonfat frozen yogurt, or sorbet, made entirely from frozen puréed fruit. Pretzels, chips, cookies, breakfast cereals, cheeses, sour cream — they all come in nonfat versions. Supermarkets now carry literally hundreds of nonfat items. The next time you go shopping, open your eyes to the new world of nonfat food alternatives. What you see — and taste — just might surprise you.

Eat mindfully. While eating, don’t do anything else. Don’t read, work, do household chores, or watch TV.

Eat breakfast. For most people it’s easier to banish the fat from breakfast than from any other meal. Try: toast with jam, apple butter, or nonfat cream cheese; a nonfat cereal or oatmeal with skim milk or nonfat yogurt and fresh fruit; or a fruit salad with nonfat cottage cheese. “A good breakfast provides energy,” Dr. Ornish explains, “and reduces midmorning food cravings that send people scurrying for danishes and donuts.”