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Human Nutrition
The document discusses the key nutrients needed by the human body and their functions. It explains that carbohydrates, fats, proteins, vitamins, minerals, fiber, and water are the basic components of food and are essential to sustain life and support cellular functions. The document provides recommendations for daily intake of calories, macronutrients, vitamins, and minerals to support a balanced, healthy diet. It compares "good" and "bad" sources of nutrients and emphasizes choosing whole, minimally processed foods over refined and processed options.
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Human Nutrition
- 1. Human Body Systems Digestion & Human Nutrition
- 2. Why do weeat? We eat to supply our cells with the molecules needed to sustain life.
- 3. Remember These? Organic Compounds found in Living Cells Molecule Building Blocks Examples Function in Cell quick energy - ATP saccharides glucose, cellulose, starch, Carbohydrates (sugars) fructose, lactose, amylose (fuel for cell processes) stored energy, triglycerides, phospholipids, Lipids fatty acids hormones cell membrane structure, chemical messengers Signaling (receptors) hemoglobin, antibodies, Structural (microtubules) enzymes, collagen, iron, Proteins amino acids microtubules, membrane Storage (iron/hemoglobin) receptors, flagella, muscles, Contractile (actin/myosin) etc. Defensive (antibodies) Enzymes (chem. reaction) Transportation stores genetic Nucleic Acids nucleotides DNA & RNA "blueprints"
- 4. Food Basics Basic components of food: Carbohydrates (simple & complex) Organic Proteins molecules Fats Vitamins Minerals Fiber Water Non-food additives in processed foods: artificial colors & sweeteners (dyes, aspartame, HFCS) chemical preservatives (nitrates, BHT/BHA) flavor enhancers (MSG)
- 5. What Are Calories? Calories are a unit of thermal energy (heat) Food Calories measure the amount of energy food gives your body The average adult needs ~ 2,000 Cal per day. Calories measure the thermal energy required to heat water 1 Calorie (capital) = 1,000 calories = 1 kcal 1 gram of water = 1 cubic centimeter (cc) 1 kg water = 1,000 cc = a 10x10x10 cm cube of water
- 6. Calories (kcal) 110 105 210 35 160 150 220 150 13 280 210 70
- 7. RDA - RecommendedDaily Allowance Nutrient Needed Amount Needed Food with This Nutritional Value Calories 2000 calories •4 Taco Bell Tacos •8 Pancakes with butter & syrup •1 ½ cheese pizzas Total Fat 65 grams •1 ¼ cups of Trail Mix (with chocolate chips) Fat: 30% •1 ½ McDonald's sausage egg biscuit 1g = 9cal •6 Fried Chicken Wings Sodium 2400 milligrams •1 teaspoon of table salt •3 dill pickles Carbs: 60% Total Carbohydrate 300 grams •2 cups of White Rice •3 cups of Grape Juice 1g = 4cal Dietary Fiber 25 grams •1 ½ cups of Refried Beans •3 ½ cups of Raisin Bran cereal Protein 50 grams •1 ½ cups of Cottage Cheese Protein: 10% •3 Chicken Drumsticks 1g = 4cal •1 Cup of Peanuts Vitamin C 60 •1 Kiwi Fruit •1 Apple or Orange Calcium 1200 milligrams •1 glass of Skim Milk •10 cups of Beans Iron 12 milligrams •2 cups of Spinach •450 g of Beef
- 8. Organic Molecules Carbohydrates – fuel for all cell functions (ATP) 60% of calories Fats (lipids) – stored energy, insulation & membrane structure 30% of calories Proteins – building materials for many cell parts & products 10% of calories
- 9. Carbohydrate Needs ~ 300 g daily needed for survival (60%) 1g Carbohydrate = 4 Calories broken down into glucose for ATP Simple Carbohydrates taste sweet monosaccharides & disaccharides listed as "Sugars" on food labels Complex Carbohydrates plant starches polysaccharides (long chains of glucose)
- 10. Carbohydrates & Insulin Simple Carbohydrates digested easily (already broken down) glucose enters bloodstream quickly 30 calories per minute Complex Carbohydrates takes longer to break down (digest) glucose enters bloodstream slowly 2 calories per minute Insulin special protein secreted by pancreas release is triggered blood sugar levels insulin signals cells to absorb glucose blood sugar lowers after insulin release sugar overload causes blood sugar fluctuations because of lag time simple carbohydrate "sugar rush" hypoglycemia symptoms 2-5 hrs. later
- 11. Carbohydrates 26g 27g 33g 8g 34g 0g 51g 25g 2g 35g 45g 0g
- 12. Protein Requirements ~ 50 g daily needed for survival (10%) 1g protein = 4 Calories broken down into 20 different amino Carboxylic Amino acids to build & repair cell components acid group group almost 20% body mass is protein Non-essential amino acids body can create these from other molecules i.e. Asparagine, Cysteine, Proline, Tyrosine Essential amino acids must get from eating foods containing them i.e. Histidine, Lysine, Methionine, Tryptophan
- 13. Protein Sources Animal Proteins meat, milk, eggs, fish "complete" contain all essential amino acids Vegetable Proteins beans, nuts, soy (tofu/edimame), grains missing some essential amino acids eating a variety can provide what is needed
- 14. Protein 2g 1g 5g 1g 6g 24g 0g 8g 2g 4g 7g 7g
- 15. Do You NEEDFat? ~ 65 g daily needed for survival (30%) 1g fat = 9 Calories break down into glycerol and fatty acids immediate or stored energy cell membrane-building to allow absorption of some vitamins Essential fatty acids must get these from food because your body can't make these molecules Too much fat average American diet has too much fat problems associated with obesity: heart disease diabetes cancer stroke many others
- 16. "Good" & "Bad"Fat Unsaturated fat ("better") liquid at room temperature most vegetable (plant) oils olive oil is a mix of fats healthier because they are less harmful than saturated fat (especially monounsaturated) Saturated fat ("bad") solid at room temperature lard, shortening, & animal fat Trans-fatty acids hardened vegetable oil "hydrogenated oils" raise LDL ("bad" cholesterol) levels
- 17. Fat (lipids) .5g .5g 2g 0g 2g 6g 0g 3g 0g 14g 1g 5g
- 18. Vitamins Vitamins are small molecules your body needs to keep itself running properly Found in fresh, "whole" foods Processing destroys vitamins, so many processed foods are "fortified" with man-made vitamins.
- 19. What Do VitaminsDo? Water Soluble readily absorbed into bloodstream kidneys filter out excess B Vitamins Thiamine, Riboflavin, Niacin, Pyridoxine, B12, Folic Acid Vitamin C (ascorbic acid) immune system, longevity, lowering cholesterol Pantothenic acid healthy skin, hair, eyes, liver & nervous system Biotin helps your body break down food and use it for energy Fat Soluble only absorbed with fat possible to overdose since kidneys can't filter out Vitamin A eyesight, healthy skin & cancer prevention Vitamin D strong teeth & bones (calcium absorption) Vitamin E fighting toxins (antioxidant) Vitamin K blood clotting, bone cell production
- 20. Minerals Elements our bodies must have in order to create other needed molecules Calcium - used by teeth, bones Chlorine, Chromium, & Copper Fluoride - strengthens teeth Iodine - used to create the hormone thyroxine Iron - transports oxygen in red blood cells Magnesium, Manganese, & Molybdenum Phosphorus Potassium - important ion in nerve cells Selenium, Sodium Zinc - healthy immune system & digestion
- 21. Sodium (Na) A mineral; enters our diet as salt (NaCl) Too much sodium causes water to stay in the bloodstream, causing hypertension diffusion = low to high concentration hypertension = high blood pressure heart disease stroke osteoporosis stomach cancer kidney disease Less than 2400 mg of sodium is the RDA.
- 22. Sodium (in mg) 0 1 105 78 320 350 0 570 48 140 0 70
- 23. McDonalds - Calories•Fat•Sodium 350•19•750 250•9•480 (burger only) w/ fries: 490•20•640 470•30•900 360•16•800 520•26•1100 (burger only) 560•37•1400 350•9•820 meal: 1290•51•1540
- 24. Taco Bell -Calories•Fat•Sodium 550•22•1270 200•11•370 780•42•1380 370•11•960 650•39•1300 970•58•1670
- 25. Subway - Calories•Fat•Sodium Black Forest Cheese adds 5 g fat Ham (no Mayo adds 12g fat cheese) Ranch adds 110 cal 290•4½•830 Mustard adds 5 cal (and no fat) Spicy Italian 480•24•1520 cheese or (without Veggie condiments) Delight 230•2½•310 (no cheese or condiments) Chicken & Bacon Ranch Melt Tuna (no cheese) 470•24•620 Chips, cookies, & specialty Sweet Onion breads will add fat, calories and 570•28•1080 Teriyaki sodium as well. (no cheese or extra 380•4½•900
- 26. Water Lost through: urine (kidneys) sweat breathing 40 oz/day needed to replenish (minimum) more needed when hot, exercising, or ill Many fruits have surprisingly high water content Caffeinated beverages actually deplete the body's water
- 27. Fiber Plant materials we eat that our bodies cannot digest fiber passes straight through the digestive system ~ 25 - 35 g recommended each day for healthy digestion expands in stomach, creating a longer "full" feeling aids digestion (stimulates smooth muscle, prevents constipation) lowers blood cholesterol, slows digestion to stabilize blood sugar Processed foods strip away most of the fiber Hemicellulose found in the hulls of grains wheat, oats, rice, bran, barley, corn Cellulose structural component of plants (especially skins/peels, legumes) a complex carbohydrate which some animals can digest Pectin found most often in fruits "water-soluble fiber" which forms a gel
- 28. A Well-Balanced Diet A healthy diet contains: fresh, whole (unprocessed) foods low-fat, low-salt sources of protein vitamin & mineral-rich foods enough Calories (but not too many) a balance of fats, protein, & carbohydrates a variety of fruits, vegetables & grains
- 29. Good vs. BadNutrients Good Bad Unprocessed, high in fiber, Refined, processed, artificial Carbohydrates "whole" natural foods additives - empty calories Fruits, vegetables, beans, whole grain candy, baked goods with refined white examples: breads/cereals/pastas flour, white pastas, soda pop, sugary juice Mono- and Poly-unsaturated Fats fats, Omega fatty acids Saturated and Trans fats nuts, seeds, avocado, canola, olive, & meat, dairy, egg yolks, seafood, coconut examples: safflower oils, fish, corn, soy (small bits) & palm kernel oils, packaged & fried foods Low fat animal sources, Protein unprocessed, vegetables High fat, additives, salty Nuts, seeds, lean beef/chicken/pork, egg bacon, hot dogs, fried shrimp, chicken examples: whites, fish, grain burgers, hummus, nuggets, beef jerky, sausage, whole milk, lentils, beans, mozzarella cheese, yogurt cheddar cheese Virtually all foods contain some of each type of nutrient 1 cup cooked rice has 5g protein & spaghetti has about 7g protein 1 cup cooked pinto beans has almost 16 g protein AND 45 g carbohydrate 2 tablespoons of peanut butter has 8 g protein, 7 g carbohydrate and 16 g fat
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- 32. Quick Review: Bones How many bones do humans have? 206 What five jobs do bones do? - structural support, attachment of muscles for movement, protection of organs, produce blood cells, & store minerals Which bones comprise the appendicular skeleton? - shoulders, arms, hips, legs, Give an example of each: long, flat, short and irregular bone. Describe each of the 3 tissues that form bones. - compact, spongy, marrow Give an example of each type of joint: hinge, ball & socket, saddle/gliding, pivot. H: jaw/knee; B&S: hip/shoulder; S: thumb; P: neck What do cartilage, ligaments and tendons do? Cartilage: pads joints Ligaments: connect bone to bone Tendons: connect muscle to bone or other muscle
- 33. Quick Review: Muscles How many muscles do humans have? almost 650 Name 3 kinds of muscle tissue. Cardiac, Skeletal, Smooth What are voluntary muscles? muscles you control (skeletal muscles) How do muscles work? in pairs, they only pull, each attaches to 2 bones, fibers are bundled together, individual cells contract What are actin & myosin? microtubules slide alongside each other to shorten the muscle fiber List some of the harmful affects of steroid abuse. stunted growth, hair loss, hair growth, high blood pressure, liver tumors, infertility, aggression, mood swings, stroke, heart, attack, acne, breast growth
- 34. Quick Review: Skin What does skin protect against? physical damage, disease, dehydration, heat & cold Name the 3 skin layers. Epidermis, Dermis, Hypodermis What is found in each layer? Epidermis - tight, thin sheets of cells, melanocytes, touch/pain/heat receptors Dermis - hair, sweat & oil glands, nerves, blood vessels, collagen/elastin Hypodermis - fat for protection/insulation How does skin regulate body temperature? sweat glands & hair/pili List some environmental factors that can cause dermatitis, acne, or skin cancer? hormones, grease from cosmetics or environment, contact, stress, soaps, dryness, allergens, sunlight, fair-skinned,
- 35. Review: Digestion What organs comprise the digestive system? Mouth, salivary glands, esophagus, stomach, gall bladder, liver, & pancreas, small intestine, colon What are the two primary purposes of the digestive system? 1 - extract nutrients & water from food/beverages In whichstore and does most of the water in 2 - organ eliminate leftover waste food get absorbed into the bloodstream? products Colon (large intestine) What two structures keep chyme contained in the stomach until ready for release? Esophageal & pyloric sphincters How does the liver aid in digestion? makes bile, which breaks down fat (lipid molecules) What structures in thefrom blood (alcohol/drugs) removes ingested toxins small intestine increase the diffusion of nutrients into the bloodstream? villi: folds in the intestinal wall microvilli: finger-like projections of cell membranes
- 36. Review: Excretion Organs of the Urinary Tract Blood flows into kidneys Nephrons clean blood Filtered blood flows back into circulatory system Waste products flow down thin tubes called ureters Urine is stored in the bladder Urine exits body via urethra
- 37. Carbohydrate Digestion, 1g= 4cal 1. Saliva begins to break down sugars Polysaccharide Chain simple sugars break down quickly complex carbohydrates take longer to digest (fiber & starch) 2. In stomach, most carbs have already been digested into single or double sugars Disaccharides (mono- or disaccharides) some glucose diffuses into bloodstream here (active transport) 3. Intestines absorb remaining carbohydrates Monosaccharides most sugars are first sent to the liver for conversion to into glucose and release into the bloodstream excess glucose is stored in the liver (up to i.e. galactose, fructose 100g) or muscles (up to 500g) as glycogen with the help of insulin, blood glucose is transported into cells for ATP production glucose ATP 4. Carbs that cannot be used by cells or stored as glycogen are converted into fat
- 38. Fat Digestion, 1g= 9cal mechanical digestion & bile salts chop up Big Lipid big molecules in intestines Molecule emulsifiers & smooth muscle peristalsis break down big lipids into smaller droplets pancreatic juices then surround fats as they are further broken up monoglycerides and fatty acids diffuse into microvilli cells Fatty smooth ER & Golgi process molecules before sending them into bloodstream Monoglycerides Acids fat-soluble vitamins (A, D, E, & K) tag along with fats as they cross membranes body uses or stores for energy, to produce hormones, & to replace cell structures
- 39. Protein Digestion, 1g= 4cal Whole Protein Chain Stomach acid and enzymes (pepsin) break long chains into short segments Peptide Fragments Pancreatic juices break bonds further in the intestine Amino acids enter intestinal wall cells via active transport or endocytosis bloodstream carries to cells Amino Acids DNA provides instructions to build antibodies & hemoglobin, muscle fibers, collagen in skin, & other cell structures
Editor's Notes
- #3 As you get older, your % of water goes down.
- #7 Which has the most calories? (Snickers bar) Which has least? (Spinach)
- #8 Determined by the FDA (Food & Drug Administration), with help from the US Food and Nutrition Board (FNB) of the National Academy of Sciences.) . Based on a 2,000 Cal diet. Does not account for individual differences in nutritional needs. Is NOT comprehensive!
- #10 The word "carbohydrate" comes from the fact that glucose is made up of carbon and water. The chemical formula for glucose is: C6H12O6. Glucose is made of six carbon atoms (carbo...) and the elements of six water molecules (...hydrate). Glucose is a simple sugar , meaning that to our tongues it tastes sweet. There are other simple sugars that you have probably heard of. Fructose is the main sugar in fruits. Fructose has the same chemical formula as glucose (C6H12O6), but the atoms are arranged slightly differently. The liver converts fructose to glucose. Sucrose, also known as "white sugar" or "table sugar," is made of one glucose and one fructose molecule bonded together. Lactose (the sugar found in milk) is made of one glucose and one galactose molecule bonded together. Galactose, like fructose, has the same chemical components as glucose but the atoms are arranged differently. The liver also converts galactose to glucose. Maltose, the sugar found in malt, is made from two glucose atoms bonded together. Glucose, fructose and galactose are monosaccharides and are the only carbohydrates that can be absorbed into the bloodstream through the intestinal lining. Lactose, sucrose and maltose are disaccharides (they contain two monosaccharides) and are easily converted to their monosaccharide bases by enzymes in the digestive tract. Monosaccharides and disaccharides are called simple carbohydrates . They are also sugars -- they all taste sweet. They all digest quickly and enter the bloodstream quickly. When you look at a "Nutrition Facts" label on a food package and see "Sugars" under the "Carbohydrates" section of the label, these simple sugars are what the label is talking about. There are also complex carbohydrates , commonly known as "starches." A complex carbohydrate is made up of chains of glucose molecules. Starches are the way plants store energy -- plants produce glucose and chain the glucose molecules together to form starch. Most grains (wheat, corn, oats, rice) and things like potatoes and plantains are high in starch. Your digestive system breaks a complex carbohydrate (starch) back down into its component glucose molecules so that the glucose can enter your bloodstream. It takes a lot longer to break down a starch, however. If you drink a can of soda full of sugar, glucose will enter the bloodstream at a rate of something like 30 calories per minute. A complex carbohydrate is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute (reference). You may have heard that eating complex carbohydrates is a good thing, and that eating sugar is a bad thing. You may even have felt this in your own body. The following quote from The Yale Guide to Children's Nutrition explains why: If complex carbohydrates are broken down to monosaccharides in the intestines before they are absorbed into the bloodstream, why are they better than refined sugar or other di- or mono-saccharides? To a great extent it has to do with the processes of digestion and absorption. Simple sugars require little digestion, and when a child eats a sweet food, such as a candy bar or a can of soda, the glucose level of the blood rises rapidly. In response, the pancreas secretes a large amount of insulin to keep blood glucose levels from rising too high. This large insulin response in turn tends to make the blood sugar fall to levels that are too low 3 to 5 hours after the candy bar or can of soda has been consumed . This tendency of blood glucose levels to fall may then lead to an adrenaline surge, which in turn can cause nervousness and irritability... The same roller-coaster ride of glucose and hormone levels is not experienced after eating complex carbohydrates or after eating a balanced meal because the digestion and absorption processes are much slower.
- #11 There are also complex carbohydrates , commonly known as "starches." A complex carbohydrate is made up of chains of glucose molecules. Starches are the way plants store energy -- plants produce glucose and chain the glucose molecules together to form starch. Most grains (wheat, corn, oats, rice) and things like potatoes and plantains are high in starch. Your digestive system breaks a complex carbohydrate (starch) back down into its component glucose molecules so that the glucose can enter your bloodstream. It takes a lot longer to break down a starch, however. If you drink a can of soda full of sugar, glucose will enter the bloodstream at a rate of something like 30 calories per minute. A complex carbohydrate is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute (reference). You may have heard that eating complex carbohydrates is a good thing, and that eating sugar is a bad thing. You may even have felt this in your own body. The following quote from The Yale Guide to Children's Nutrition explains why: If complex carbohydrates are broken down to monosaccharides in the intestines before they are absorbed into the bloodstream, why are they better than refined sugar or other di- or mono-saccharides? To a great extent it has to do with the processes of digestion and absorption. Simple sugars require little digestion, and when a child eats a sweet food, such as a candy bar or a can of soda, the glucose level of the blood rises rapidly. In response, the pancreas secretes a large amount of insulin to keep blood glucose levels from rising too high. This large insulin response in turn tends to make the blood sugar fall to levels that are too low 3 to 5 hours after the candy bar or can of soda has been consumed . This tendency of blood glucose levels to fall may then lead to an adrenaline surge, which in turn can cause nervousness and irritability... The same roller-coaster ride of glucose and hormone levels is not experienced after eating complex carbohydrates or after eating a balanced meal because the digestion and absorption processes are much slower. Common symptoms of hypoglycemia include the following: trembling, clammy skin, palpitations (pounding or fast heart beats), anxiety, sweating, hunger, and irritability. When the brain remains deprived of glucose, a later set of symptoms follows: difficulty in thinking, confusion, headache, seizures, and coma.
- #12 Which have highest source of carbs? (potato, noodles, snickers, bread, yogurt) Which are simple? (Banana, yogurt, juice, snickers) Complex? (noodles, bread, beans, potato, spinach, carrot)
- #13 A protein is any chain of amino acids . An amino acid is a small molecule that acts as the building block of any cell . Carbohydrates provide cells with energy, while amino acids provide cells with the building material they need to grow and maintain their structure. Your body is about 20-percent protein by weight. It is about 60-percent water. Most of the rest of your body is composed of minerals (for example, calcium in your bones). Amino acids are called "amino acids" because they all contain an amino group (NH2) and a carboxyl group (COOH), which is acidic. Below you can see the chemical structure of two of the amino acids. You can see that the top part of each is identical to the other. That is true of all amino acids -- the little chain at the bottom (the H or the CH3 in these two amino acids) is the only thing varying from one amino acid to the next. In some amino acids, the variable part can be quite large. The human body is constructed of 20 different amino acids (there are perhaps 100 different amino acids available in nature). As far as your body is concerned, there are two different types of amino acids: essential and non-essential. Non-essential amino acids are amino acids that your body can create out of other chemicals found in your body. Essential amino acids cannot be created, and therefore the only way to get them is through food. Here are the different amino acids: Non-essential Alanine (synthesized from pyruvic acid), Arginine (synthesized from glutamic acid), Asparagine (synthesized from aspartic acid) ,Aspartic Acid (synthesized from oxaloacetic acid), Cysteine, Glutamic Acid (synthesized from oxoglutaric acid), Glutamine (synthesized from glutamic acid), Glycine (synthesized from serine and threonine), Proline (synthesized from glutamic acid), Serine (synthesized from glucose), Tryosine (synthesized from phenylalanine) Essential Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine Protein in our diets comes from both animal and vegetable sources. Most animal sources (meat, milk, eggs) provide what's called " complete protein ," meaning that they contain all of the essential amino acids. Vegetable sources usually are low on or missing certain essential amino acids. For example, rice is low in isoleucine and lysine. However, different vegetable sources are deficient in different amino acids, and by combining different foods you can get all of the essential amino acids throughout the course of the day. Some vegetable sources contain quite a bit of protein -- things like nuts, beans, soybeans, etc. are all high in protein. By combining them you can get complete coverage of all essential amino acids. The digestive system breaks all proteins down into their amino acids so that they can enter the bloodstream. Cells then use the amino acids as building blocks. From this discussion you can see that your body cannot survive strictly on carbohydrates. You must have protein. According to this article, the RDA (Recommended Daily Allowance) for protein is 0.36 grams of protein per pound of body weight . So a 150-pound person needs 54 grams of protein per day. The photo above is the Nutritional Facts label from a can of tuna. You can see that a can of tuna contains about 32 grams of protein (this can has 13 grams per serving and there are 2.5 servings in the can). A glass of milk contains about 8 grams of protein. A slice of bread might contain 2 or 3 grams of protein. You can see that it is not that hard to meet the RDA for protein with a normal diet.
- #14 A protein is any chain of amino acids . An amino acid is a small molecule that acts as the building block of any cell . Carbohydrates provide cells with energy, while amino acids provide cells with the building material they need to grow and maintain their structure. Your body is about 20-percent protein by weight. It is about 60-percent water. Most of the rest of your body is composed of minerals (for example, calcium in your bones). Amino acids are called "amino acids" because they all contain an amino group (NH2) and a carboxyl group (COOH), which is acidic. Below you can see the chemical structure of two of the amino acids. You can see that the top part of each is identical to the other. That is true of all amino acids -- the little chain at the bottom (the H or the CH3 in these two amino acids) is the only thing varying from one amino acid to the next. In some amino acids, the variable part can be quite large. The human body is constructed of 20 different amino acids (there are perhaps 100 different amino acids available in nature). As far as your body is concerned, there are two different types of amino acids: essential and non-essential. Non-essential amino acids are amino acids that your body can create out of other chemicals found in your body. Essential amino acids cannot be created, and therefore the only way to get them is through food. Here are the different amino acids: Non-essential Alanine (synthesized from pyruvic acid), Arginine (synthesized from glutamic acid), Asparagine (synthesized from aspartic acid) ,Aspartic Acid (synthesized from oxaloacetic acid), Cysteine, Glutamic Acid (synthesized from oxoglutaric acid), Glutamine (synthesized from glutamic acid), Glycine (synthesized from serine and threonine), Proline (synthesized from glutamic acid), Serine (synthesized from glucose), Tryosine (synthesized from phenylalanine) Essential Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine Protein in our diets comes from both animal and vegetable sources. Most animal sources (meat, milk, eggs) provide what's called " complete protein ," meaning that they contain all of the essential amino acids. Vegetable sources usually are low on or missing certain essential amino acids. For example, rice is low in isoleucine and lysine. However, different vegetable sources are deficient in different amino acids, and by combining different foods you can get all of the essential amino acids throughout the course of the day. Some vegetable sources contain quite a bit of protein -- things like nuts, beans, soybeans, etc. are all high in protein. By combining them you can get complete coverage of all essential amino acids. The digestive system breaks all proteins down into their amino acids so that they can enter the bloodstream. Cells then use the amino acids as building blocks. From this discussion you can see that your body cannot survive strictly on carbohydrates. You must have protein. According to this article, the RDA (Recommended Daily Allowance) for protein is 0.36 grams of protein per pound of body weight . So a 150-pound person needs 54 grams of protein per day. The photo above is the Nutritional Facts label from a can of tuna. You can see that a can of tuna contains about 32 grams of protein (this can has 13 grams per serving and there are 2.5 servings in the can). A glass of milk contains about 8 grams of protein. A slice of bread might contain 2 or 3 grams of protein. You can see that it is not that hard to meet the RDA for protein with a normal diet.
- #15 Which have highest source of protein? (chicken, beans, egg, noodles) Which are "complete"? (chicken, egg, yogurt) Incomplete? (Banana, yogurt, juice, snickers, noodles, bread, beans, potato, spinach, carrot)
- #16 Two kinds of fats: saturated and unsaturated . Saturated fats are normally solid at room temperature, while unsaturated fats are liquid at room temperature. Vegetable oils are the best examples of unsaturated fats, while lard and shortening (along with the animal fat you see in raw meat) are saturated fats. However, most fats contain a mixture. For example, above you see the label from a bottle of olive oil. It contains both saturated and unsaturated fats, but the saturated fats are dissolved in the unsaturated fats. To separate them, you can put olive oil in the refrigerator. The saturated fats will solidify and the unsaturated fats will remain liquid. You can see that the olive oil bottler even chose to further distinguish the unsaturated fats between polyunsaturated and monounsaturated . Unsaturated fats are currently thought to be more healthy than saturated fats, and monounsaturated fats (as found in olive oil and peanut oil) are thought to be healthier than polyunsaturated fats. Fats that you eat enter the digestive system and meet with an enzyme called lipase . Lipase breaks the fat into its parts: glycerol and fatty acids. These components are then reassembled into triglycerides for transport in the bloodstream. Muscle cells and fat (adipose) cells absorb the triglycerides either to store them or to burn them as fuel. You need to eat fat for several reasons: As we will see in the next section, certain vitamins are fat soluble. The only way to get these vitamins is to eat fat. In the same way that there are essential amino acids, there are essential fatty acids (for example, linoleic acid is used to build cell membranes). You must obtain these fatty acids from food you eat because your body has no way to make them. Fat turns out to be a good source of energy. Fat contains twice as many calories per gram as do carbohydrates or proteins. Your body can burn fat as fuel when necessary.
- #17 Two kinds of fats: saturated and unsaturated . Saturated fats are normally solid at room temperature, while unsaturated fats are liquid at room temperature. Vegetable oils are the best examples of unsaturated fats, while lard and shortening (along with the animal fat you see in raw meat) are saturated fats. However, most fats contain a mixture. For example, above you see the label from a bottle of olive oil. It contains both saturated and unsaturated fats, but the saturated fats are dissolved in the unsaturated fats. To separate them, you can put olive oil in the refrigerator. The saturated fats will solidify and the unsaturated fats will remain liquid. You can see that the olive oil bottler even chose to further distinguish the unsaturated fats between polyunsaturated and monounsaturated . Unsaturated fats are currently thought to be more healthy than saturated fats, and monounsaturated fats (as found in olive oil and peanut oil) are thought to be healthier than polyunsaturated fats. TRANS FATTY ACIDS These fats form when vegetable oil hardens (a process called hydrogenation) and can raise LDL levels. They can also lower HDL levels ("good cholesterol"). Trans fatty acids are found in fried foods, commercial baked goods (donuts, cookies, crackers), processed foods, and margarines. HYDROGENATED AND PARTIALLY HYDROGENATED FATS This refers to oils that have become hardened (such as hard butter and margarine). Partially hydrogenated means the oils are only partly hardened. Foods made with hydrogenated oils should be avoided because they contain high levels of trans fatty acids, which are linked to heart disease. (Look at the ingredients in the food label.)
- #18 Which are "better" sources of fat? (beans, pasta, banana/OJ) Which are "bad"? (Snickers, chicken, egg, yogurt) Fish, nuts, and olive/canola oils are some of the healthiest sources of fat.
- #23 Which are "better" sources of fat? (beans, pasta, banana/OJ) Which are "bad"? (Snickers, chicken, egg, yogurt) Fish, nuts, and olive/canola oils are some of the healthiest sources of fat.
- #26 All 6 inch subs, without mayo, sauce, or any condiments or sides. On standard white bun.
- #27 Too much water can be bad for certain people (high blood pressure).
- #28 Fiber is the broad name given to the things we eat that our bodies cannot digest . Hemicellulose is found in the hulls of different grains like wheat. Bran is hemicellulose. Cellulose is the structural component of plants. It gives a vegetable its familiar shape. Pectin is found most often in fruits, and is soluble in water but non-digestible. Pectin is normally called "water-soluble fiber" and forms a gel. When we eat fiber, it simply passes straight through, untouched by the digestive system. Cellulose is a complex carbohydrate . It is a chain of glucose molecules. Some animals and insects can digest cellulose. Both cows and termites have no problem with it because they have bacteria in their digestive systems secreting enzymes that break down cellulose into glucose. Human beings have neither the enzymes nor these beneficial bacteria, so cellulose is fiber for us.
- #38 Photo Credit cristal-glass sugar-bowl and white sugar image by Maria Brzostowska from Fotolia.com The human body has an efficient and complex system of storing and preserving energy. Glucose is a type of sugar that the body uses for energy. Glucose is the product of breaking down carbohydrates into their simplest form. Carbohydrates should make up approximately 45 to 65 percent of your daily caloric intake, according to MayoClinic.com. Food Sources of Glucose Glucose is a simple sugar found in carbohydrates. When more complex carbohydrates such as polysaccharides and disaccharides are broken down in the stomach, they break down into the monosaccharide glucose. Carbohydrates serve as the primary energy source for working muscles, help brain and nervous system functioning and help the body use fat more efficiently. Function of Glucose Once carbohydrates are absorbed from food, they are carried to the liver for processing. In the liver, fructose and galactose, the other forms of sugar, are converted into glucose. Some glucose gets sent to the bloodstream while the rest is stored for later energy use. Stored Glucose Once glucose is inside the liver, glucose is phosphorylated into glucose-6-phosphate, or G6P. G6P is further metabolized into triglycerides, fatty acids, glycogen or energy. Glycogen is the form in which the body stores glucose. The liver can only store about 100 g of glucose in the form of glycogen. The muscles also store glycogen. Muscles can store approximately 500 g of glycogen. Because of the limited storage areas, any carbohydrates that are consumed beyond the storage capacity are converted to and stored as fat. There is practically no limit on how many calories the body can store as fat. Liver Glycogen The glucose stored in the liver serves as a buffer for blood glucose levels. Therefore, if the blood glucose levels start to get low because you have not consumed food for a period of time, the liver is able to release glucose into the bloodstream to maintain healthy levels. Blood glucose levels are tightly regulated because glucose is the primary energy source for the central nervous system. Blood glucose also is important for sustaining brain functioning. If the body reserves of glucose deplete, a process called gluconeogenesis will take place. During gluconeogenesis, glucose is synthesized from molecules that are not carbohydrates. Often, this means the body will break down muscle fibers to obtain the molecules to produce glucose. Muscle Glycogen Muscle glycogen reserves are stored energy for the muscles. The glycogen is able to be broken back down into glucose when the muscle contracts and requires energy. The body is able to store 500 g of glycogen, roughly equivalent to 2,000 calories, in the muscles. Therefore, if you did not eat for a day, you will have drastically depleted these stores. After an intense workout, when these glycogen stores have been tapped into, consuming carbohydrates will replenish these reserves. Read more: http://www.livestrong.com/article/264767-how-is-excess-glucose-stored/#ixzz2NwmNN6e6