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FINAL REVIEW Intro to Nutrition
Essential • A necessary nutrient that can be obtained only from the diet • The body cannot make for itself • or cannot make enough
Organic - contains carbon protein mineral fat carbohydrate vitamin
Energy Yielding Nutrients protein fat carbohydrate
Malnutrition • A deficiency of nutrients • An imbalance of nutrients • An excess of nutrients • An individual can be overweight and malnourished
Nutritious Diet • Adequacy: getting enough nutrients • Balance: proportionality • Variety: different types of foods • Moderation: not too much of any one food • Calorie Control: getting enough energy, but not too much energy
DRI • FAT: 20-35% total calories • SATURATED FAT: < 10% of total calories AHA < 7% • TRANS FAT: as low as possible (<1%) • CHOLESTEROL: < 300mg • CARBOHYDRATE: 45-65% of total calories • ADDED SUGAR: < 10% of total calories • PROTEIN: 10-15% upper limit 35% • or 0.8g/kg
Research Designs Epidemiological: studies of populations Case study: study of an individual Interventional Study: experimental manipulation Placebo controlled: One group being studied is given a sham treatment Blinded: either the group being studied or the investigator does not know who is taking the sham treatment * Gold Standard: Placebo controlled double blinded
Leading Causes of Death Related to Nutrition: • Heart Disease • Cancer • Stroke • Diabetes
Nutrient Structure • all are organic • all have carbon, hydrogen and oxygen • all provide energy • only protein has nitrogen
RDA vs AI • Nutrient recommendations for individuals • RDA: indisputable scientific evidence • AI: educated guess based on research
EER: Energy Requirement Energy Requirement
Phytochemicals • Non-nutrient plant chemicals which have a beneficial effect on the body • Can act as antioxidants • NOT proven to prevent disease • NOT guaranteed to make us live longer
Fruit vs Vegetable • Fruit is a plant which includes the seeds of that plant (edible portion surrounding the seeds) • A vegetable is the remaining edible portions of that plant (roots, stems, leaves, etc) • USDA divides foodsinto subgroupsbased on nutrients
Illusions • Dr. Wansink tested Nutrition Experts by giving them big bowls and big scoops or small bowls and small scoops. • These experts scooped 53% more ice cream with big bowls and big scoops!
Daily Values • Great for comparing products • Not a good tool for recommendations for individuals • Same on every label
Digestion and Absorption • Mouth • Stomach • Intestines • Liver • Gallbladder • Colon
Stomach & Acid • How does the stomach avoid getting burned by stomach acid?
Stomach & Acid • How does the stomach avoid getting burned by stomach acid? • Secrete mucus which protects them from the acidic contents of the stomach
Digestion & Absorption • Digestion: Breakdown of nutrients • Absorption: passage of nutrients from the digestive tract to the bloodstream
Heartburn Recommendations • Smaller, more frequent meals • Drink before and after meals, not during • minimize fiber • Don’t lie down immediately after meals • Wear loose clothing
Storage Systems Carbohydrates are stored? Fat is stored? Protein is stored?
Storage Systems • Carbohydrates are stored? • Liver (glycogen) and Adipocytes (fat) • Fat is stored? • Adipocytes (fat) • Protein is stored? • Not stored in the body, but excess is converted to fat and stored in adipocytes
Simple Carbohydrates disaccharides monosaccharides
Carbohydrates Simple Carbohydrates Complex Carbohydrates fiber glycogen
Fiber (Table 4-2) Soluble (upper GI) • Lower blood cholesterol by binding bile • Slow glucose absorption ( DM,CAD) • Slow transit through upper GI tract • Hold moisture Insoluble (lower GI) • Increase fecal weight • Increase speed through colon ( constipation) • Provide bulk and feeling of fullness (help with weight loss)
Blood Sugar Blood sugar : results in insulin secretion by the pancreas Blood sugar : results in glucagon secretion by the pancreas
Wheat Kernel A: Husk - removed B: Bran - most of fiber C: Endosperm - starch D: Germ - nutrients/ protein
Diabetes • Type I Diabetes • Autoimmune disease • Cells of the pancreas do not secrete insulin • Typical onset is childhood • Type II Diabetes • Insulin resistance • Pancreas secretes enough or too much insulin • Typically adult-onset, now seen in children
Lipids • Three classes of lipids • Triglycerides (TG) • ≈95% of all lipids in foods and the human body. TG = FAT • Phospholipids • For example, lecithin • emulsifiers • Sterols • For example, cholesterol * Know functions of lipids
Lipids • Triglycerides • Main form of fat storage in the body • Main for of fat we consume • Three fatty acids and a glycerol (carbon backbone)
Fatty Acids • Essential Fatty Acids • Omega - 6 • Omega - 3
Lipoproteins • LDL • Transport cholesterol and other lipids to body tissues • HDL • Carry cholesterol from body cells to the liver for disposal (scavenges cholesterol)
Trans Fatty Acids Trans fats are a byproduct of hydrogenation
Cholesterol • LDL increases heart disease risk • HDL increases heart disease risk • Dietary cholesterol has little impact on blood cholesterol • Decrease saturated and trans fat • More impact than decreasing cholesterol intake
Proteins • Genes determine the sequence • String of amino acids • Peptide bond • Not a straight chain • Shape determines function.
Proteins • Multiple functions - we don’t want to use proteins for energy • Antibodies • Enzymes • Connective Tissue (muscle, ligament, etc) • Hormones • Acid Base Balance • Buffers
Using Proteins for Energy • Nitrogen is wasted when protein is used for energy
Digestibility • Dry heat digestibility: BBQ • Moist heat digestibility • Crock pot / stew • Meat - better digestibility • Grain - lower digestibility
Denaturing Protein • Uncoiling and unfolding protein • acid (stomach acid) • heavy metals (ie: mercury) • base • heat (cooking) • alcohol
PEM • KWASHIOKOR • Older infants ( 1-3 yr) Rapid onset • Inadequate protein intake • Some weight loss and muscle wasting (not severe) • Edema (belly) • Belly often bulges with a fatty liver • MARASMUS • 6 - 18 months of age • Protein and energy deprivation • Develops slowly • Severe wasting • No edema • Looks like a Little Old Man/matchstick arms • Can go to point of no return
Vegetarian/Vegan Diet • A healthy vegetarian diet is associated with a lower risk of chronic disease • Both a vegetarian diet and a meat eater’s diet should include a wide variety of fruits and vegetables and whole grains • A vegan diet needs to be supplemented with Vitamin B12 • Mutual supplementation is the combining of plant foods to form complete proteins
Vitamin A • Vision • Growth and maintenance • Needed by the body linings and skin • For growth of bones and teeth • Immune defenses Can be toxic from food (Vit A potentially the most toxic)
Beta - carotene • Precursor to Vitamin A • Not toxic from foods • Supplements are not recommended • Can turn the skin orange • Plant source
Other Fat Soluble Vitamins Vitamin D Vitamin E Vitamin K
Other Fat Soluble Vitamins Vitamin D Regulate blood calcium Vitamin E Antioxidant / works with Selenium Vitamin K Forms blood clotting and bone proteins * Given to infants a birth because they do not have vitamin K producing bacteria
Other Fat Soluble Vitamins Vitamin D - deficiency Vitamin E - deficiency Vitamin K - deficiency
Other Fat Soluble Vitamins Vitamin D - deficiency Rickets Vitamin E - deficiency Erythrocyte hemolysis in premature infants Vitamin K - deficiency Fractures and bleeding
Other Fat Soluble Vitamins Vitamin D - SEVERE deficiency Rickets Low levels of Vitamin D associated with • Osteoporosis • Autoimmune diseases (RA, type 1 DM) • Some cancers (colorectal, breast, prostate) • Hypertension (high blood pressure)