An example of a snack low in energy density is

Nutrition Assignment

What Are the Key Principles of Healthy Eating? 41

Healthy Eating Means Consuming a Variety of Foods Choosing a variety of foods improves the quality of the diet because the more var- ied the food choices, the better the chance of consuming adequate amounts of all the essential nutrients.2 Even within one food group, the nutrient composition of foods can vary dramatically. For example, while broccoli is a good source of folate, it has less than half the vitamin A of a carrot. Similarly, if the only fruit you eat is bananas, your diet would include an excellent source of potassium, but could be low in vitamin C. Because no single food or food group contains everything you need to be healthy, you should choose a variety of foods from within each food group and among food groups each day. This is the basic principle of the Fruits & Veggies—More Matters campaign developed by the Produce for Better Health Foundation and the Centers for Disease Control and Prevention.3 This campaign promotes eating a vari- ety of colorful fruits and vegetables—which are rich in vitamins, minerals, fiber, and phytochemicals—each day to help reduce the risk of cancer and heart disease and slow the effects of aging.

Healthy Eating Means Moderate Intake of All Foods According to many registered dietitian nutritionists (RDNs), “there are no good or bad foods, just good or bad habits.” What they mean is that all foods—even less nutritious foods—can be part of a healthy diet, as long as they are consumed in moderation. Foods such as sweets and fried or packaged snack foods should be eaten only in small amounts to avoid consuming too much sugar and saturated fat, as well as too many kilocalories. Finally, these foods can displace more nutritious choices, resulting in a diet that lacks essential nutrients. Even some healthy foods, such as nutrient-dense nuts, can be high in kilocalories and should be consumed in moderation. Healthy eating doesn’t mean you can’t enjoy your favorite foods. It simply means eating those foods in moderation by lim- iting the portion size and number of servings you eat.

Many people overestimate the appropriate portion sizes of foods. An entire body of research is devoted to studying factors that affect how much we put on our plates. The important point is that, in general, we tend to consume portions larger than necessary to meet our kilocalorie needs. See the Health Connection on pages 65–67 for examples of visuals you can use to estimate portion sizes. For suggestions on eating a balanced, varied, and moderate diet, see the Table Tips.

Healthy Eating Includes Nutrient-Dense Foods Healthy eating also means choosing foods that are nutrient dense. Nutrient-dense foods are high in nutrients, such as vitamins and minerals, but low in energy (kilocalories), pro- viding more nutrients per kilocalorie (and in each bite) than less nutrient-dense foods.4 Fresh fruits and vegetables, for example, are nutrient dense because they are high in B vitamins, vitamin C, and minerals such as calcium and magnesium, as well as dietary fiber, while usually providing fewer than 60 kilocalories per serving.

Nutrient-dense foods are also low in saturated fat and added sugars. To illustrate this concept, compare the nutrient density of two versions of the same food: a baked potato and potato chips (Figure 2.1). Although a medium baked potato and one ounce of potato chips have about the same number of kilocalories, the baked potato provides much higher amounts of vitamins and minerals than the deep-fried chips.

Though many foods, such as vegetables, are clearly nutrient dense, and other foods, such as candy, are clearly not, some foods do not fit neatly into these two categories. Items such as dried fruits, nuts, peanut butter, and avocados are higher in kilocalories, but they are also excellent sources of important nutrients, including polyunsaturated fatty acids, calcium, and iron. Other foods, such as whole milk or yogurt, are higher

portion Quantity of a food usually eaten at one sitting.

Choosing a variety of nutrient-dense foods you enjoy is a key to eating a healthy diet.

TABLE TIPS

Tips for a Balanced, Varied, and Moderate Diet

Keep healthy snacks such as whole- grain crackers in your dorm room and combine them with protein-rich peanut butter or low-fat yogurt.

Pop a snack-pack size of light micro- wave popcorn for a portion-controlled whole-grain snack while you study.

Adopt a multicolor code to guide your food choices. Add tomato slices and a low-fat cheese slice to your whole-grain sandwich and carrots to your tossed green salad to ensure that your choices are adequate and varied.

Pack your own snack-sized portions of dried fruit, trail mix, whole-wheat crack- ers, baby carrots, or salt-free pretzels to carry in your backpack. Snack-sized bags of nuts and seeds are a nutri- tious way to help you avoid the vending machine and eat smaller, more moder- ate portions.

Keep your sweets to no more than about 100 kilocalories a day.

42 Chapter 2 | Tools for Healthy Eating

in saturated fat and kilocalories than their nonfat or low-fat counterparts, but still pro- vide significant amounts of calcium, riboflavin, vitamins A and D, and protein. Some foods, such as fruit-flavored yogurt and some fortified cereals, contain added sugars in addition to several essential nutrients. Do you think these foods can be considered nutrient dense?

In all of these scenarios, the answer is yes. Whereas nutrient dense usually means high in nutrients and low in energy, foods that are high in nutrients and high in energy can also be considered nutrient dense. The key is to be aware of the extra kilocalories and make up for them elsewhere in the diet. If you don’t like skim milk and won’t drink it, but do enjoy the taste of whole milk, then drinking whole milk is a more healthy choice than drinking soda.

Healthy Eating Includes Low-Energy-Dense Foods In contrast to nutrient density, energy density refers to foods that are high in energy but low in weight or volume, such as that potato chip. A serving of deep-fried chips weighs much less than a plain baked potato, but is considerably higher in kilocalories. Therefore, the chip contains more energy per gram. A big, leafy green salad, on the other hand, is large in volume but low in energy density, because of its high water content.

Most high-fat foods are considered energy dense.5 This is because fat has 9 kilocalories per gram and is thus 2.25 times more energy dense than either carbohy- drates or protein at 4 kilocalories per gram. Individuals who choose low-energy-dense foods will generally have diets that are lower in fat and higher in nutrient content.

Eating a low-energy-dense diet can sometimes be the key to weight loss. Recent studies have found that leaner individuals ate more low-energy-dense foods and fewer kilocalories, while consuming a greater volume of food, compared with their obese counterparts.6 Even modest changes in dietary intake may promote and help maintain weight loss7 over time.8 One reason for this may be that eating higher-volume, lower- energy foods means larger portions for the same number of kilocalories. Other reasons may include improved satiety and appetite control.9 In other words, low-energy foods will “fill you up before they fill you out.”

If you are trying to maintain your current weight, or lose weight, you are probably on a limited energy budget and need to choose foods that are nutrient dense and low in kilocalories. Use the guide in Table 2.1 to help stretch your energy budget while con- suming the most nutrient-dense foods.

satiety Feeling of satiation, or “fullness,” after a meal before hunger sets in again.

▲ Figure 2.1 Which Is the Healthier Way to Enjoy Potatoes? Whereas one ounce of potato chips and one medium baked potato have similar kilocalories, their nutrient content is worlds apart. A baked potato contains more folate, potassium, and vitamin C, and fewer fat kilocalories, than its fried counterpart. The baked potato is therefore more nutrient dense than potato chips. * Note: Based on the percentage of the DRI for 19- to -50-year-old males. All these percentages apply to females in the same age range, except for vitamin C. Females have lower vitamin C needs than males, so a baked potato provides over 20 percent of the DRI of this vitamin for women.

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Potato chips, 1 oz

Baked potato, medium

Vitamin CPotassiumFolate