Nutrition PDF

Chapt er 24 Nutrition, Metabolism, and Energy Balance 927 Are you a food lover? We are too. In fact, most people fall into one of two groups-those who live to eat and those who eat to live. The saying "you are what you eat" is true in that part of the food we eat is converted to our livin...

Chapt er 24 Nutrition, Metabolism, and Energy Balance 927 Are you a food lover? We are too. In fact, most people fall into one of two groups-those who live to eat and those who eat to live. The saying "you are what you eat" is true in that part of the food we eat is converted to our living flesh. In other words, our bodies use some nutrients to bu ild cell struc- tures, replace worn-out parts, and synthesize functional mole- cules. However, most nutrients we ingest are used as metabolic fuel. That is, they are oxidized a nd transformed to ATP, the chemical energy form used by cells ( Distinguish between simple and complex carbohydrate While "essential" is a standard way to describe the chemicals sou rces. that must be obtained from outside sources, both essential and ll> Distinguish between sat urated, unsaturated, and t rans nonessential nutrie nts are equally vi tal for normal functioning. fatty acid sources. Most foods offer a combination of nutrients. A balanced ll> Distinguish between nutritionally complete and diet of foods from each of the different food groups normally incomplete proteins. guarantees adequate amounts of all the needed nutrients and ll> Define nitrogen balance and indicate possible causes o f adequate e nergy. positive and negative nitrogen balance. The energy value of foods is measured in kilocalories (kcal). ll> Indicate the major uses of carbohydrates, lipids, and One kilocalorie is the amount of heat energy needed to raise proteins in the body. the temperature of I kilogram of water 1°C ( l.8°F). This unit is the "calorie" (C) that dieters cou nt so conscientiously. Not Carbohydrates all foods have the same amount of energy. Carbohydrates and Dietary Sources proteins each have 4 kcal per gram, but lipids have almost 9 kcal Except for mi lk sugar (lactose) and negl igible amounts of per gram. glycogen in meats, all the carbohydrates we ingest are derived Various organizations release dietary recornmendations. Most from plan ts. Sugars (monosaccharides and disaccharides; of these ernphasize eating more vegetables, whole grains, and fruits. 928 UNIT 4 Maintenance of the Body pp. 43-44) come from fruits, sugar cane, sugar beets, honey,