To help Americans eat healthfully, scientists have developed nutritional guidelines. One of these is the Food Guide Pyramid, which places Choose...breads, pastas, whole grain foodsmeatsdairysweets including cakes, snacks, and ice cream at the bottom and Choose...breads, pastas, whole grain foodsmeatsdairysweets including cakes, snacks, and ice cream at the top to remind people how to construct a healthy diet. Another help to consumers is the Nutrition Facts Label, which lists nutritional values in a food product based on Choose...content in order of weightpercent daily valuesamount of fatserving size. Food has three functions: to provide chemical constituents of the body; to provide energy; and to be pleasurable. Among the chemical constituents are Choose...vitaminsmineralsessential nutrientsrecommended ingredients, 40 chemical substances that the body cannot manufacture for itself. Energy from food fuels basal metabolism, physical activity, and growth. The principal function of dietary protein is to provide Choose...energy for basal metabolismvitamins for energybuilding blocks for body tissuesabout 65 percent of body mass. Carbohydrates provide energy and Choose...simple sugarscomplex carbohydratesnucleosidesfiber, nondigestible material that aids digestion. Much of the fat consumed in the diet provides the body with fatty acids. Vegetable oils contain Choose...saturated fatty acidspolyunsaturated fatty acidscholesteroltrans-fatty acids, which are healthier than Choose...saturated fatty acidspolyunsaturated fatty acidscholesteroltrans-fatty acids, which are derived from meat, eggs, and dairy. Vitamins and minerals help the body carry out its many chemical reactions. Dietary supplements are commercial products that consist of vitamins, minerals, herbs and other compounds. Dietary supplements can be used to augment the nutritional quality of the diet and/or they can be used as drugs, in which case they are called Choose...functional foodsneutraceuticalsphytochemicalsmultivitamins. A variety of chemicals are added to foods. Some are to combat spoilage (preservatives), some to add color (dyes), and others to add taste (salt and sweeteners). Food can be rendered harmful when it becomes contaminated with bacteria. One way to increase the safety of foods is to expose them to Choose...sulfiteslaser treatmenttartrazinegamma irradiation, which destroys bacteria, fungi and other microorganisms. Each day, about 20 percent of the U.S. population eats fast food, much of which is calorie-dense and nutritionally inadequate.