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LEARNING OBJECTIVES
After studying this chapter, the reader should be able to:
1.1 Describe the roles of carbohydrate in the body.
1.2 Identify food sources containing carbohydrates.
1.3 Explain the factors that constitute a high-quality carbohydrate.
1.4 Briefly describe the process of carbohydrate digestion and absorption.
1.5 Outline the process of carbohydrate metabolism.
1.6 Define and describe glycemic index.
1.7 List several benefits of a high-fiber diet.
1.8 List various types of carbohydrates and their effect on athletic performance, weight management, and overall health.
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KEY TERMS
absorption The transfer of nutrients from the digestive system into the blood supply.
acceptable macronutrient distribution range (AMDR) The range of intake for a macronutrient that is associated with decreased risk of chronic disease while providing sufficient intake of essential nutrients.
adenosine triphosphate (ATP) The body's usable energy source.
amylopectin A polysaccharide highly branched chain of glucose molecules that is easily digested.
amylose A polysaccharide made of glucose molecules bound together in a linear chain that is mostly resistant to digestion.
bolus A food and saliva digestive mix that is swallowed and further digested in the stomach and small intestine.
brush border The site of nutrient absorption in the small intestine. Enterocyte cells line the small intestine and have microvilli. The microvilli are closely packed together and resemble the bristles of a brush. The enterocyte cells secrete enzymes and proteins that assist with nutrient digestion and absorption.
calorie The amount of energy needed to increase 1 kilogram of water by 1 degree Celsius. It is used to measure the amount of energy in a food available after digestion.
carbohydrate A macronutrient made of carbohydrate, hydrogen, and oxygen; the body's preferred energy source.
cellulose A low viscosity starch made of long chains of glucose; a structural component of the cell wall in plants that is indigestible to humans.
chyme A partially digested mass of food formed in the stomach and released into the duodenum of the small intestine.
complex carbohydrates Oligosaccharides and polysaccharides; multiple monosaccharides joined by glycosidic bonds; takes more time to digest than a simple carbohydrate.
dietary fiber Nondigestible carbohydrates and lignins that are obtained naturally from plant foods.
digestion The process of breaking down food into units small enough for absorption.
disaccharide A simple carbohydrate; two monosaccharides bound together. Maltose, fructose, and lactose are all disaccharides.
duodenum The approximately 1-foot long first portion of the small intestine where the majority of chemical digestion of food occurs.
enzymes Proteins that speed up the rate of chemical reactions.
esophagus A muscular tube extending from the mouth to the stomach.
fructooligosaccharide A category of oligosaccharides that are mostly indigestible, may help to relieve constipation, improve triglyceride levels, and decrease production of foul-smelling digestive byproducts.
fructose The sweetest of the monosaccharides, found in varying levels in different types of fruits.
functional fiber Nondigestible carbohydrates that have been isolated from foods and added to food products, and ...