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The Science of Nutrition. A Microscopic to Macroscopic Approach. Today’s Agenda. JEOPARDY Lipids Vitamins & Minerals Nutritional Density. JEOPARDY. Split into two equal teams and get out your note books. Lipids. Types of Lipids Fatty Acids Fats, and Oils
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The Science of Nutrition A Microscopic to Macroscopic Approach
Today’s Agenda • JEOPARDY • Lipids • Vitamins & Minerals • Nutritional Density
JEOPARDY Split into two equal teams and get out your note books.
Lipids Types of Lipids Fatty Acids Fats, and Oils Chemical Properties of Triglycerides
Types of Lipids • Lipids with fatty acids Waxes Fats and oils (trigycerides) Phospholipids Sphingolipids • Lipids without fatty acids Steroids
Fats Fat refers to the class of nutrients known as lipids. The lipid family includes triglycerides (fats and oils), phospholipids, and sterols. Every triglyceride contains one molecule of glycerol and three fatty acids.
Fatty Acids Fatty acids are chains of carbon atoms with hydrogen atoms attached that have an acid group (COOH) at one end and a methyl group (CH3) at the other end.
Fatty Acids • Long-chain carboxylic acids • Insoluble in water • Typically 12-18 carbon atoms (even number) • Some contain double bonds corn oil contains 86% unsaturated fatty acids and 14% saturated fatty acids
Saturated v. Unsaturated Fatty Acids Saturated fatty acids carry the maximum possible number of hydrogen atoms, while unsaturated fatty acids lack hydrogen atoms and have at least one double bond between carbons.
Structure of Fatty Acids Saturated = C–C bonds Unsaturated = one or more C=C bonds
Structures Saturated fatty acids • Fit closely in regular pattern Unsaturated fatty acids • Cis double bonds
Properties of SaturatedFatty Acids • Contain only single C–C bonds • Closely packed • Strong attractions between chains • High melting points • Solids at room temperature
Properties of UnsaturatedFatty Acids • Contain one or more double C=C bonds • Nonlinear chains do not allow molecules to pack closely • Few interactions between chains • Low melting points • Liquids at room temperature
Fats in Your Diet • Try not to eat any trans fats • Increases bad (LDL) cholesterol, lowers good (HDL) cholesterol – risk of heart disease • Keep saturated fat consumption to a minimum • Monounsaturated and polyunsaturated fats – between 15-30% daily caloric intake • Sources: olive oil, safflower oil, peanut oil and corn oil • Avoid hydrogenated or partially hydrogenated oils – added hydrogen to make it solid, preserve – check labels!
1.What foods are high in trans fat?2.What foods are high in saturated fat?3.What foods are high in unsaturated fat?4. What do you want to avoid in your diet?
Benefits of Dietary Fats • Fat is an essential part of your diet • Vital for your cell membranes and some cellular functions • Insulates our body • Energy supplier • Absorption and transportation around body of fat soluble vitamins A, D, E and K • Fat surrounds and protects organs, including our kidneys
What do you notice? Peanut Butter Jelly
NUTRITIONAL DENSITY A Different Approach to Thinking about Nutrition
WHAT IS NUTRITIONAL DESNITY? Nutritional Density = Nutrients/Calorie • How much nutritional value (mass) per one calorie (volume)
Two Types of Nutrients Macronutrients Micronutrients
B Vitamins • Bananas, seeds, green vegetables, sweet potato, nuts • Folate • Leafy greens • Vitamin E • Almonds, seeds, asparagus • Vitamin C • Citrus, tomatoes, peppers, leafy greens • Vitamin D • Vitamin K • Cauliflower, Broccoli, Brussle Sprouts, Greens • Vitamin • Carrots, broccoli,mango, cantaloupe Vitamins Vitamins are organic substances bodies need to grow, metabolize, and develop normally. Deficiencies in vitamins can lead to disease and poor health.
Macrominerals • Calcium • Phosphorus • Magnesium • Sodium • Potassium • Sulfur • Chloride • Trace Minerals • Iron • Zinc • Copper • Selenium • Manganese Minerals Minerals are the building blocks that make up muscles, tissues, and bones and are components of hormones, oxygen transport, and enzyme systems.
Flavonoids • Glucosinolates • Cruciferous Vegetables • Keep Cancer in Check • Resveratrol • Anti-Inflammatory • Ellagic Acid • Berries • Carotenoids • Provide fruits and vegetables with red, yellow and orange color Phytonutrients Phytonutrients are natural chemicals found in plants. There are over 25,000 of them, and they help fight disease and keep the body working
The Nature of Vitamins • Vitamins are organic (carbon) compounds needed for normal function, growth and maintenance. • Vitamins are cofactors, they don’t do anything by themselves. • They are not a source of calories.
The Nature of Vitamins • Food processing can preserve nutrients.
The Nature of Vitamins • Nutritional Value lost by: • Light • Heat • Oxidation • Bacteria • Enzymes • Insects • (Nutritional value of baby foodmust be assured.) Effect of packaging on nutrient loss in milk.
Vitamin Requirements • Daily Values (DV): standard nutrient intake values developed by FDA • Includes DRIs (Daily Recommended Intakes for Individuals) and (DRVs) Daily Recommended Values (Proteins, etc.) • Disease prevention • Best met through a consumption of a wide variety of foods
Vitamin Requirements • Dietary Reference Intakes (DRI): recommendation for individuals (more accurate, but would be impossible to label) • Age • Gender • Pregnancy • Lactation
Vitamin Requirements • Daily Reference Values (DRV): standards established for protein and other dietary components lacking a RDA or nutrient standard • Constitute part of the Daily Values (DV) used on food labels
The Nature of Vitamins • Organic cofactors – what is a cofactor? • Physiological role – specific metabolic function • Prevents disease – unlike “supplements” which may promote “some thing” or have general metabolic effect (ex. Omega 3s, fibers) • Natural = Synthetic (except Vitamin E)
Dietary Supplements $6 Billion Market • They are classified as “Nutritional Supplements” They are not foods, and not drugs.* • Supplements are “Product intended to supplement the diet and contains vitamins, minerals, botanicals, amino acids, and their extracts.” • NOT consumed as a food replacement • Loosely regulated, “not evaluated by FDA” By definitiona “drug” is used to “prevent, treat or cure” disease. These terms cannot be used with supplements. Use of some supplements is backed by scientific data.
Fat Soluble Vitamins • A – orange, carotenoids, vision, antioxidant- used as color and antioxidant • D – we make it with sunlight, deficiency causes rickets, in milk, regulates Ca:P ratios • E – tocopherols, antioxidants, role in preventing stroke, cancer, heart disease- used as antioxidant • K – contributes to blood clotting factor A LOW FAT DIET MAY CAUSE MALABSORBION
Vitamin A Lots of double bonds, good anti-oxidant
Vitamin A • Carrotinoids Used in food industry as a colorant (orange) • Antioxidant • Important for sight • Dietary deficiency common in developing countries • Blindness, bone abnormalities, susceptibility to viral infections such as measles and pneumonia • If you take a dietary supplement: teens 14-18 should not consume more than 2800mcg; 19+, 3000mcg • Cooking and storage do not reduce Vitamin A • Carrotenosis
Vitamin A cont. QUICK: CARROTS
Vitamin D • Also known as calciferol due to its role in calcium absorption • Main role is to maintain calcium and potassium levels • Part of Immune System and Nerve Signaling • It is the only fat soluble vitamin that we can make- in the presence of sunlight • <1/3 of people meet dietary requirement • Can be made from cholesterol
Vitamin D • Can be stored in fat tissues (as can all fat soluble vitamins) • We get vitamin D form fortified milk and cereal • Toxicity is very dangerous • Occurs only from excess supplementation • Can lead to calcium deposits in kidneys, heart and blood vessels
Vitamin E • A family of eight naturally occurring compounds • anti-oxidant • Since aging is considered an “oxidation” reaction, many “anti-oxidants” are used as dietary supplements • Protect skin, cell communication, from foods protects against prostate cancer and Alzheimer’s • E in supplements = alpha-tocopherol; in food, gamma-tocopherol • Role is stroke, cancer, heart, and immune response • Americans spend $300 million per year on vitamin E supplements • E dependent on C, B3, selenium and glutathione
Vitamin E cont. QUICK: NUTS • Low-fat diet may cause Vitamin E deficiency (because Vitamin E is fat-soluble!) • Common in vegetable oils
Vitamin K QUICK: GREENS • Vital for blood clotting, protects bones • Works as a cofactor for an enzyme that makes two bone proteins • Resilient to cooking/freezing • Estimated daily value need is 80 micrograms
Water Soluble Vitamins • Relatively cheap to add to food • Only Vitamin C is used for its functionality
Water Soluble Vitamins • B1, thiamine • B2, riboflavin • B6, pyridoxamine • B12 • Biotin • Panothenic acid • Niacin • Folacin • Vitamin C
Water Soluble Vitamins • Vitamin B1 • Thiamine • Involved in carbohydrate metabolism • Helps body metabolize glucose, affects central nervous system • B2- riboflavin • Energy metabolism
Water Soluble Vitamins • B6 - Pyridoxamine • Neurotransmitter, co-enzyme in over 100 reactions • B12 – • Development of red blood cells • Lack of it makes one anemic • Hard for vegans to get