Encyclopedia Of Foods

Chapter 2: The Nutrients and Other Food Substances 23clean and quickly perceptible, although disagreement existsabout whether it leaves an aftertaste.A fourth intense sweetener, sucralose (Splenda), wasapproved by the FDA in 1998 for sale and use in commercialfood products. Sucralose is made by chemicallymodifying sucrose (table sugar) to a non-nutritive, noncaloricpowder that is about 600 times sweeter than sugar.Before approving sucralose, the FDA reviewed more than110 research studies conducted in both human and animalsubjects. It concluded that the sweetener is safe forconsumption by adults, children, and pregnant and breastfeedingwomen in amounts equivalent to the consumptionof about 48 pounds of sugar annually (an AcceptableDaily Intake of 5 milligrams per kilogram of body weight).People with diabetes may also safely consume the sweetener,because it is not metabolized like sugar. In addition,sucralose is highly stable to heat and so will not lose itssweetness when used in recipes that require prolongedexposure to high temperatures (such as baking) or whenstored for long periods. The product is currently availablein the form of a powdered sugar substitute and in somecommercial baked goods, jams and jellies, sweet sauces andsyrups, pastry fillings, condiments, processed fruits, fruitjuice drinks, and beverages, and its use is approved forvarious additional products. However, use of sucralose inhome baking is expected to be limited by its low bulk incomparison with table sugar.Foods containing intense sweeteners should not be givento infants or children, who need energy to grow and tosustain their high activity levels. Foods that contain intensesweeteners and lack any nutritive value also should notreplace nutrient-dense foods in your diet.The sugar alcohols xylitol, mannitol, and sorbitolcontain less than 4 calories per gram. These sugar alcoholsare digested so slowly that most are simply eliminated.Unfortunately, excessive consumption can cause diarrheaor bloating in some people.So-called “natural” sweeteners provide the same numberof calories as sugar and have acquired the reputation, albeitincorrectly, of being healthier than sugar, because they seemmore natural than processed table sugar. These includehoney, maple syrup and sugar, date sugar, molasses, andgrape juice concentrate. In reality, these sweeteners containno more vitamins or minerals than table sugar. Honeymay harbor small amounts of the spores of the bacteriathat produce botulism toxin and should never be given tobabies younger than 1 year.The Bottom Line on CarbohydratesCarbohydrates—sugars and starches—are the main sourceof fuel for our bodies. When we choose carbohydrate-richfoods, our best bets are fruits, vegetables, whole grains,and legumes, because these foods are also rich sources ofhealth-promoting vitamins, minerals, phytochemicals, andfiber. But like all calories, extra calories from carbohydratesbeyond those we need to replenish the energy we burnare converted to fat and stored in our fat cells. Non-caloricsweeteners seem to be a safe alternative to sugar for mostpeople, but the foods that contain them are often nutritionallyempty and their use in home cooking is limited. Theso-called natural sweeteners are no better for you than sugar.PROTEINProtein is an essential part of our diets. Proteins are large,complex molecules resembling tangled strings of beads.Each of the “beads” on the string is one of a group of smallermolecules called amino acids. Amino acids are composedof carbon, oxygen, hydrogen, and nitrogen, and somecontain sulfur.Using the amino acids from the protein you eat, thebody makes more than 50,000 different proteins. Theseproteins are the main structural elements of our skin, hair,nails, cell membranes, muscles, and connective tissue.Collagen, the main protein in our skin, provides a barrierto the invasion of foreign substances. Proteins in cell membranesdetermine what substances can enter and exit cells.Our muscles, which contain some 65 percent of the body’stotal protein, give our bodies their shape and strength.Proteins in connective tissues such as tendons, ligaments,and cartilage enable our skeletons to function, form internalorgans, and hold the organs in place. Proteins in theblood carry oxygen to all cells and remove carbon dioxideand other waste products. The proteins in muscle,connective tissue, and blood make up most of the proteinin the body. Other proteins called enzymes accelerate metabolicprocesses, and still other proteins and amino acidsare hormones and neurochemicals, the substances thatdeliver signals throughout the body and regulate all metabolicprocesses.During periods of growth, our bodies must manufactureand store large amounts of protein. Therefore, therequirement for protein in our diets is higher during growth.But even when we are not growing, each of the unique