NSC 170C1 1st Edition Lecture 14Outline of Last Lecture I. ProteinsOutline of Current Lecture I. Protein in foodsII. Personal need for protein A. Too little proteinB. Too much protein Current LectureI. High quality proteinA. Digestiblei. In general, animal proteins are more digestible than plant proteins90 to 99 percent of animal proteins are digestible70 to 90 percent of plant proteins are digestibleB. Has a complete amino acid profilei. The amino acid profile of a protein is the types and amounts of amino acids it containsii. Complete proteins provide all nine of the essential amino acids, along with some of the 11 nonessential amino acidsiii. Proteins from animal sources are typically complete, while proteins from plant sources are incompletea) Exceptions:Gelatin, an animal protein,lacks tryptophan.Soy is a complete plant protein.C. Complemented proteins: incomplete proteins coupled with animal proteins, soy, or other plant proteins rich in the limiting amino acidsII. Determining your personal protein needsA. Daily dietary protein for healthy adults should equal the amount of protein the body uses dailyB. Nitrogen balancei. Nitrogen balance studies can help determine daily protein needs.ii. Measure the nitrogen consumed against nitrogen excreted.iii. Healthy adults are typically in nitrogen balance.iv. Positive nitrogen balance occurs during periods of growth in infancy, childhood, and adolescence, and during pregnancy.v. Negative nitrogen balance can occur when healing from a traumatic injury, fighting fever, or during illness. Tissues will be broken down to meet needs when dietary intake is inadequate.C. Dietary protein can be expressed as: percent of total calories or grams of protein eaten per day i. Recommendationsii. 10 to 35 percent of total calories from proteiniii. 0.8 g protein per kg of body weight for adults 19 and older iv. Most Americans easily meet or exceed dietary protein needsv. Competitive athletes participating in endurance or resistance exercises need 50 to 100 percent more protein to meet their needs.a) Protein is abundant in dairy foods, meat, fish, poultry, and meat alternatives such as dried beans, peanut butter, nuts, and soy.b) Grains and vegetables provide less protein, but can aid in meeting your daily needs.III. Eating too much protein can be harmful A. A diet too high in protein can be associated with risk of: i. Heart Diseaseii. Many protein rich foods are higher in saturated fats creating:a) kidney stonesb) osteoporosis (poor bone density) c) CancerLarge amount of meats (especially red meats) can increase therisk of colon cancerIV. Eating too little protein can also be harmful A. Protein-energy malnutrition (PEM): A lack of dietary protein and/or caloriesi. Most frequently seen in infants and childrenii. Causes include poverty, poor food quality, insufficient food intake, unsanitary living conditions, ignorance of how to properly feed children, and stopping breast-feeding too earlyiii. Can lead to life-threatening health problems, including compromised immunity, infection, and diarrheaB. Kwashiorkor: PEM disorder caused by severe protein deficiencyi. Protein deficiency causes fluid accumulation in the spaces surrounding the cellsii. Characterized by edema in the legs, feet, and stomach, decreased muscle strength and tone, dry and peeling skin, infection, and water and electrolyte imbalancesC. Marasmus: PEM disorder resulting from deficiency of caloriesi. Characterized by a frail, emaciated appearance, thin and dry hair, low blood pressure and body temperature, and risk of infection and
View Full Document
Unlocking...