310 likes | 316 Views
Learn about nutrients, digestion, dietary needs, and common diseases related to nutrition. Discover recommended dietary intakes, food energy, and the importance of proteins and fats. Gain insights into caloric requirements and the impact of processed foods on health.
E N D
Nutrition K. Dunlap
Nutrition the study of food and how the body uses it Function of Nutrients: 1) supply energy 2) supply materials for building and replacing body tissues 3) supply other substances needed for various life processes
Nutrition • Nutrients: the components of food and drink that provide growth, replacement, and energy: • 1. Carbohydrates • 2. Lipids • 3. Proteins • 4. Vitamins • 5. Minerals • 6. Water • Digestion: the hydrolysis of starches, fats, and proteins into smaller units that can be absorbed and metabolized.
DRI- Dietary Reference index • Food and Nutrition Board, the institute of Meidcin and the National Academy of Sciences has established the DRIs • EAR: adequate amount for 50% of population • EER: estimated energy requirements • RDA: recommended dietary allowances are adequate for most of the population based on measurable parameteres • AI: Adequate intakes are used when REDA & EARs are not available • UL: upper tolerance limit. Above would be detrimental
Calorimeter • Food energy is measured in Calories (capital C) 1 Cal = 1 kcal = 1000 cal = 4180 joules • a Calorie is defined as the amount of energy required to raise 1 kg of water 1C • Measured in a bomb calorimeter
Calculating the Caloric Value of Food Carbohydrate = 4 Cal per gram Proteins = 4 Cal per gram Fats = 9 Cal per gram
Nutrition & Health • Poor diet and sedentary life style = Risk factors chronic diseases • Accounts for about 66% of all deaths • Cardiovascular diseases (29%) • Cancer (22%) • Cerebrovascular diseases (7%) • Diabetes (3%)
Nutritional Diseases • Obesity - excessive weight gain that is associated with heath concerns and increased risk of mortality • -characterized by a BMI of greater than 30 • BMI (body mass index) = weight in kg divided by the square of the height in m • 25% of Americans are obese • 60% of Americans are overweight (BMI 25-29.9)
Nutritional Diseases • Diabetes - condition in which body is unable to utilize glucose in a normal way • Type I - an auto immune disease that results in the permanent destruction of insulin producing beta cells in the pancreas • Type II - metabolic disorder that is usually characterized by insulin resistance, insulin deficiency and hyperglycemia • associated with obesity • Increased prevalence
Metabolic syndrome • Is a cluster of at least three of five of the following medical conditions: • abdominal (central) obesity • Elevated fasting plasma glucose • High serum triglycerides • Low HDL • Insulin resistance – a condition in which the body does not respond properly to insulin.
Type 2 diabetes • US population: 9.3% • 7th leading cause of death • AI/AN: 15.9% • Alaskan Natives alone (5-9%)
asubsistencelifestyle • low incidence of age and nutritional diseases • 4.8 kg subsistence foods per week • 60% of subsistence foods is finfish
Proteins • Human body is 10-20% protein • 40-50% in skeletal muscle • 20% in organs • Rest in skin and blood • Recommended Daily Intake: • Adults: 0.8 g per kg of body weight • Children and Pregnancy: 1.5-2.0 g per kg body weight • Complete Protein - contains all essential amino acids • -meat, eggs, dairy, fish • Incomplete Protein - missing one or more essential amino acids • -legumes and grains combined make a complete protein
Proteins • Gelatin, which is denatured collagen, is an incomplete protein because it lacks Trp, and is low in Ile and Met. • Corn protein is low in Lys and Trp. • Rice is low in Lys and Thr. • Wheat protein is low in Lys. • Legumes are low in Met and Cys. • Soy protein is very low in Met. • Protein complementation: a diet in which two or more proteins complementation each other’s deficiencies; for example: • grains + legumes (rice + beans)
Fats • recommended 30% of diet • -10% monounsaturated • -10% saturated • -10% unsaturated Essential Fatty acids: Omega-3 EPA, DHA, linoleic Omega-6 Arachidonic acid, -linolenic • EPA, DHA, AA are 20 carbon hormone-like fatty acids that play an important part in the immune function
Saturated Fats in the U.S. Diet • >90% of Fas in US diet: • Palmitic (16:0) • Stearic (18:0) • Oleic (18:1) • Linoleic (18:2)
Energy Needs Woman 2000 Cal Men 2200 Cal -physical activity and lifestage affects energy needs -need to burn 3500 Cal to lose 1 pound Basal Caloric Requirements -the requirements for a resting body
Problems with Processed Food • nutrients are lost in processing • some but not all nutrients are • added back (Enriched) • Fortified is when other • ingredients are added • that were not originally • the food • are lower in fiber • processed foods are • digested more quickly and • lend to weight gain
Food Supplements • vitamins, minerals, herbal remedies, etc… • $60 billion a year industry • Balanced diet provides adequate needs • Elderly, dieters, alcoholics, pregnant, lactation may require supplementation • often supplements are not in a form that is as available as it is in food
Supplement Label
Nutrition Labels
Food Additives -added to prevent spoilage, sweeten, enhance flavor, color, appearance, emulsify
Food Preservatives • mostly used to prevent food spoilage • Antimicrobial: • Nitrites • clostridium botulism • identified as cancer-causing • Sulfites • -wine and dried fruit • -can cause allergic rxn • Others • -Na, K, Ca salts, benzoic acid, propionic acid, sorbic acid
Food Preservatives cont…. • Antioxidants: added to slow the oxidative process • -usually phenols • Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) • Prevent oxidation of fats by combining with free radicals • Natural Antioxidants • -Vitamin E, Vitamin C, carotenoids, other polyphenols • -also stop oxidation by combining with free radicals
Chemical Structures of Flavorings -largest class of food additive • natural and synthetic • Mostly aldehydes and esters • Many synthetics have not been thoroughly tested
Chemical Structures of Artificial Sweeteners -growing market for dieters and diabetics Sucralose Splenda NutriSweet
How does the body store energy? How many Cal of energy are released 180 grams of glucose are converted to CO2 and H2O? There are 2 fatty acids that the body needs but cannot synthesize. What are they? What is meant by a complete protein?