Post on 09-Jun-2015
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NutritionWhat should my diet look like?
MyPyramid.gov
• Developed by USDA• Personal guide to
healthy eating & physical activity
• Based on age, gender, activity level
• How does this pyramid compare to the old Food Guide Pyramid?
Anatomy of MyPyramidActivity: • Importance of daily
physical activity• At least 30 min. / day• 60 min. / day of
moderate to intense activity more beneficial
Moderation:• Narrowing of each
food group• Base represents
nutrient rich food w/ essential vitamins and minerals & fewer calories
• Top represents foods containing more added sugars & solid fats
Proportionality:• Different widths of food
groups• Widths suggest how much
food should be eaten from each group
Variety:• 6 color bands
representing 5 food groups & oils
• Food from all groups are needed for healthy nutrition
Personalization & Gradual Improvement:• Small steps everyday for YOU!!!
• Orange = Grains• Green = Vegetables• Red = Fruits• Yellow = Healthy
Fats/Oils• Blue = Dairy• Purple = Meat &
Beans
MyPyramid.gov
What Are YOUR Caloric Needs?
• Use MyPyramid.gov to discover YOUR needs– Individual food plan for caloric needs
– Tract diet & physical activity for up to 1 year
– Detailed info on each food group’s serving sizes, nutrients, & health benefits
– Info for special populations (i.e. pregnant, overweight, elderly, children)
6 Categories of Nutrients• Carbohydrates (CHO)• Lipids (Fats)• Proteins• Vitamins• Minerals• Water
Macronutrients
Micronutrients
Division of Total Daily Caloric (kcal) Intake
• CHO: 50-60%• Fat: 25-30% or less• Protein: 10-20%
– (0.8 grams per kg of body weight)
Carbohydrate2 Hydrogen for each Oxygen
C6H12O6
Glucose = simplest form of sugar
A Sugar is a Sugar is a….
•Glucose•Dextrose•Fructose•Lactose•Maltose•Sucrose
•Granulated sugar
•Confectioner’ sugar•Brown sugar•Corn syrup•Honey
•Invert sugar•Maple syrup•Molasses•Mannitol•Sorbitol•Sorghum
Categories of Carbohydrates
• Monosaccharides (glucose, fructose, galactose)
• Disaccharides (sucrose, maltose, lactose)
• Polysaccharides (starch, fiber, glycogen)
Monosaccharides = Simple Sugar Units• Glucose - Blood Sugar
– Found in fruits & vegetables– Used for:
• Cell energy• Stored as glycogen in muscles & liver• Converted to fat for energy storage
• Fructose - “Fruit Sugar”– Found in fruit, honey, corn syrup
• Galactose– Found as part of lactose in milk
Disaccharides = 2 Monosaccharides
Monosaccharides & Disaccharides = Simple Sugars
Sucrose = Glucose + Fructose (brown sugar; 25% of sugar intake)
Lactose = Glucose + Galactose (milk sugar; least sweet)
Maltose = Glucose + Glucose (honey)
50% of average American dietary CHO intake = simple sugars
Polysaccharides = 3 or more simple sugars combine
• Plant Polysaccharides:– Starch
• Peas, seeds, corn, grains, cereals, potatoes, roots
– Cellulose• Fiber (technically not a nutrient – resistant to digestion)
– Water-insoluble– Water-soluble– ***Recommended fiber intake = 20-35 g per day
Dietary Fiber
• Water-Soluble Fiber – Depress synthesis & absorption of cholesterol in gut– Bind existing cholesterol to facilitate excretion in feces– Ex: pectin & guar gum in oats, beans, peas, carrots, fruits
• Water-Insoluble Fiber – Hold water & give bulk to food residues in small intestine
increasing stool weight/volume– Ex: cellulose, hemicellulose, lignins, pectins in brown rice,
corn, & wheat bran• Health Implications of Fiber:
– Colorectal cancer, diabetes, intestinal disorders (stool issues), cholesterol effects
Dietary Fiber• Average American eats 12 g of fiber / day
• Recommended Intake of Fiber = 20-35 g / day– Insoluble to soluble = 3:1
• Guess who has the highest incidence of colorectal cancer?
Polysaccharides = 3 or more simple sugars combine
• Animal Polysaccharides:– Glycogen
• Ranges in size from few hundred to thousands of glucose molecules liked together like sausage links
• Storage form of glucose• 375-475 g stored in body (liver, muscle, kidney)• Can be modified by diet & exercise• Most important energy fuel
Functions of CHO
• Important Energy Source
• Protein Sparer
• Metabolic Primer
• Central Nervous System Fuel
Source of CHO• Dairy• Fruits• Cereals• Breads• Pasta
Big Issue = Simple vs. Complex CHO
Preferred Choice=
Complex CHO
BUT…
Recommended CHO Intake
• Percent of daily total caloric intake = 50-60%
• So, if I eat 1200 kcal / day, 600 – 700 kcal should be from carbohydrates
• 1 gram of CHO = 4 kcalCalorie (kcal) =
unit of heat used to express energy
value of food
What are the Fates of Blood Glucose?
Blood Glucose
Muscle Glycogen
Adipose Tissue
Used for Energy
Kidney Excretion
Liver Glycogen
Nature of Lipids
• Same structural elements as CHO but linking of atoms is different (C, H, & O)
• The H to O2 ratio is typically 18.3:1– (CHO is 2:1)
• Found in both plants & animals• 3 kinds of lipids
– Simple, Compound, & Derived• Generally greasy to touch & insoluble in water
Kinds of Lipids – Simple Fats
• aka Neutral Fats• Triglyceride
– Most common & plentiful fat in body
– More than 95% of body fat is triglyceride (primary storage form)
– Composed of 2 different atom clusters
• Glycerol (3 carbon sugar) + 3 Fatty Acids
Simple Fats:
Fatty Acids• Give each fat unique qualities of flavor & texture• Differ in:
– Length of carbon chain– Bonding of carbon atoms & arrangement of
hydrogens along carbon chain• 3 Kinds of Fatty Acids:
– Saturated– Unsaturated– Essential
Saturated Fatty Acid• A saturated fatty
acid contains only single bonds between C atoms; all remaining bonds attach to hydrogen– The fatty acid
molecule holds as many H+ atoms as possible - thus the term saturated
• Found primarily in animal products:– Beef– Lamb– Pork– Chicken– Egg yolk– Cream, milk, butter, cheese (Dairy)– Coconut and palm oil– Vegetable shortening– Hydrogenated butter
Saturated Fatty Acids
• Contain one or more double bonds along the main C chain - the fatty acid is unsaturated with respect to H+
• Mono-unsaturated: 1 double bond (olive, canola, and peanut oil)
• Poly-unsaturated: 2 or more double bonds (safflower, sunflower, soybean, corn oil)
Unsaturated Fatty Acids
Unsaturated Fatty Acids
Each double bond takes the
place of 2 hydrogen
atoms
Saturated vs Unsaturated Fat
Regardless of the degree of saturation, all
lipids have essentially the
same number of calories per unit
weight.
1 g of fat = 9 kcal
Essential Fatty Acids
• Polyunsaturated fatty acids– Linoleic acid = Omega-6 fatty acid
• Vegetable oil, corn oil, sunflower oil, peanut oil
– Alpha-linolenic acid = Omega-3 fatty acid• Green leafy vegetables, canola oil, soy products, fish
• Must be consumed from food/diet• Serve as precursors of other fatty acids which
body can not synthesize
Eicosapentaenoic acid (fish oil)
–Found in oils of shell fish, cold-water tuna, herring, sardines, mackerel & sea mammals
• CHD protective • Prevents blood clot formation on arterial walls• Lowers blood pressure• Increases plasma HDL• Decreases LCL cholesterol
Omega-3 Fatty Acids
Eat fish – 10 ounces / week!!!
Hydrogenation• Oils exist as liquids & contain unsaturated fatty acids• Hydrogenation changes oils to semi-solid fat
– Bubbles liquid hydrogen into vegetable oil w/ mineral catalyst nickel
• Reduces unsaturated fatty acids’ bonds from double bonds to single bonds– More hydrogen attach to carbons
• Firmer fat results b/c hydrogen increases lipid’s melting temp.• Hydrogenated oil behaves like a saturated fat
Trans Fatty Acids• Hydrogenation of vegetable oils
– Unsaturated corn, soybean & sunflower oil
• Results when one of the H+ moves from its naturally occurring position to the opposite side of the double bond– 17-25% in margarine– 7% in butter– Possible links to heart disease
• (30,000 deaths / year)
Kinds of Fat - Derived Lipids• Cholesterol
– Exists only in animal tissue– No FFA but shares similar characteristics– Exists as endogenous cholesterol
• 0.5 - 2.0 g/d production• More forms with high saturated diets
– Functions include: building plasma membranes, synthesizing Vit D, adrenal gland hormones and sex hormones (estrogen, androgen, progesterone), bile; tissue and organ formation during fetal development.
Recommended Cholesterol Intake• 300 mg (1/100 oz) / day or LESS!!!
• 100 kCal per 1000 kCal ingested– 1 cup skim milk = 4 mg– 1 cup whole milk = 33 mg– 3 oz beef = 680 mg
Fat in the Diet• Average American now consumes 15% of total kCal
(>50 lbs) of saturated fat per year, most of which is animal in origin
• 25-30% of total daily kcal intake should be fat– More unsaturated– Less saturated– Try to avoid trans fat, hydrogenated fats
Fat in the Diet
Roles of Fat 1. Energy source and reserve
-9 kCal/g2. Protection and insulation3. Vitamin carrier4. Satiety
Protein• Most abundant
organic compound in body
• Found in living matter
• Growth & repair of body tissue
Protein Organization• Chemical organization similar to fats & CHO,
except protein also contains nitrogen
• Nitrogen = 16% of protein molecule
• Basic units – “building blocks” – of protein are Amino Acids (AA)
Proteins & Amino Acids (AA)• Amino Radical – NH2
• Organic Acid Radical – COOH• Side Chain – R
– Determines differences between amino acids
Amine + Acid = Amino Acid
23 Different Amino Acids
Essential/Nonessential AAEssential (cannot be synthesized by the body and be obtained from food)
HistidineIsoleucineLysineMethioninePhenylalanineThreonineTryptophanValine
Nonessential (made in the body)
AlanineArginineAsparagineCysteineGlutamic acidGlutamineGlycineProlineSerineTyrosine
Proteins in Foods• Proteins can be found in both animals and plants
• Nothing “better” about an amino acid from animal compared to same amino acid from plant origin
• Proteins in food classified as complete or incomplete depending on amino acid content
Proteins in Foods
• Complete aka High-Quality Protein– Contain all essential AA in quality & correct proportion to
maintain nitrogen balance & promote normal growth– Usually animal products (eggs, milk, meat, fish, poultry)
• Incomplete aka Lower-Quality Protein– Lacks one or more of the essential AA– Usually plant products (nuts, lima beans, lentils)
Complimentary Function of Proteins• All essential amino acids can be consumed by eating
variety of vegetable foods
• Example: Grains & legumes– Grains lack AA lysine which legumes have– Legumes lack AA methionine which grains have– Tortillas & beans; rice & beans; rice & lentils; rice & peas;
peanuts & wheat bread
• B/c large amounts of these foods must be eaten to obtain required amount of AA, people eat animal products
Protein RDA0.8 - 0.9 grams/kg BW
Examples–50 kg (110 lb) person = 40 g (1.4 oz)–85 kg (187 lb) person = 68 g (2.4 oz)
Your Protein Needs
• Determine ideal body weight• Determine protein needs:
– Older Teen – 0.9 g / kg BW– Adult – 0.8 g / kg BW– Adult Athlete – 1.1 – 1.6 g / kg BW– Pregnant – add 10 g– Lactating – add 15 g for 1st 6 months & 12 g after
• Body Weight X Need = Protein Requirement
Functions of Proteins
• Anabolism• Structural proteins• Enzymes• DNA, RNA• Blood Plasma• Vitamin precursor• 1g = 5.65 kCal
– Reduces to 4 kcal
FATE OF AMINO ACIDS
• Gluconeogeneis - 18 AA serve as a source for glucose synthesis
• Energy Source - Oxidized for energy in Krebs cycle
• Fat Synthesis - All AA provide a potential source for fat synthesis
Semivegetarian - avoids only certain kinds of meat, fish, poultryLacto-ovo vegetarian - avoids eating any animal flesh, but uses dairy products and eggsLacto-vegetarian - avoids eating animal flesh and eggs, but uses dairy productsVegan - avoids all foods of animal origin, even dairy products and eggsMacrobiotic Vegetarian - ten dietary stages; Fruitarian- includes only fruit, nuts, honey and olive oil
Nonprotein Consumers
WHAT ARE VITAMINS?
• Essential organic substances • Needed in MINUTE amounts by body • Perform specific metabolic functions
• When vitamin is synthesized from existing chemicals in body the ingredient to make the conversion are called pro-vitamins– Ex: Carotine – Vitamin A
Where do Vitamins Come From?
• All vitamins found in green leaves & roots of plants (photosynthesis)
• Exception: Vitamin B12 – found only in animals
• Man cannot synthesize Vitamin C & most of fat soluble vitamins
FUNCTIONS OF VITAMINS• essential links and regulators in metabolism• tissue synthesis
2 Types of Vitamins
• Fat-Soluble– A (Retinol)– D (Cholecaciferol)– E (Tocopherol)– K (Menadione)
• Water-Soluble– C (Ascorbic Acid)– Thiamin– Riboflavin– Niacin– B-6 (Pyridoxine)– Pantothenic Acid– Biotin– Folate– B-12
FAT SOLUBLE VITAMINS
A, D, E, K–Daily ingestion unnecessary –Stored in the liver, fat cells and
subcutaneously–No mechanism to leave the body–Can be toxic in excess
VITAMIN ARDA = 0.8 - 1.0 mg
• Functions– Constituent of visual pigment– Antioxidants– Maintenance of epithelial tissues
• Food Sources– Yellow-orange vegetables– Orange fruits– Dark-green leafy vegetables
VITAMIN D
RDA = .005 - .01 mg• Functions
– Promote growth & mineralization of bones– Increases absorption of calcium
• Food Sources– Dairy products– Cod-liver oil– Eggs– (Non-food source) Sunlight!!!
VITAMIN D Deficiency
• Rickets = vitamin D deficiency disease of children
• Osteomalacia = vitamin D deficiency in adults (softening of bones, making them brittle)
VITAMIN E• A vitamin in search of a disease!
“no known evidence of dietary deficiency of vitamin E in humans”
RDA = 15 mg
• Functions– Anti-oxidant to prevent cell membrane
damage• Food Sources
– Seeds– Green leafy vegetables– Margarines & shortenings
VITAMIN K
• Functions– Blood clotting– Formation of bone
• Food sources– Green vegetables– Liver– Egg yolks
RDA = .06-.08 mg
Water Soluble Vitamins• Vitamin C & B-complex group
– Transported throughout water medium of the body
– Not stored in body– Voided in urine– Must be consumed regularly - daily
B Vitamins• B vitamins act primarily as
coenzymes• Work as catalysts• Function in energy-producing
metabolic reactions• Includes:
– Thiamin 1.1 -1.2 mg/day– Riboflavin 1.1-1.3 mg/day– Niacin 14-16 mg/day– B6 1.3-1.7 mg/day– Folate 0.2 mg/day– B12 0.002 mg/day
VITAMIN C
• Increases absorption of iron• Influences serum cholesterol• Affects immune system• Affects synthesis of collagen• Affects drug metabolism• Protects DNA in sperm• Maintains intercellular matrix of cartilage, bone, &
dentine
RDA = 75-90 mg
Minerals• 4% of body mass
composed of 22 metallic elements called minerals
• Important minerals found in enzymes, hormones, & vitamins
• Classified as major or minor
Major and Minor Minerals
• Minor Minerals(intake needed < 100 mg/day)
– iron– zinc– copper– selenium– iodine– fluorine– chromium– molybdenum– manganese
• Major Minerals• (intake needed >100 mg/day)
– sodium– potassium– calcium– phosphorus– magnesium– sulfur– chlorine
Bioavailability of Minerals
• Extent that mineral is absorbed by body & made available for its biologic functions
• Affected by:– Vitamin-Mineral Interaction
• Synergism in consuming some vitamins & minerals together
• Example: calcium & vitamin D
– Fiber-Mineral Interaction• Example: Too much fiber decreases absorption of
calcium, zinc, magnesium, iron
Where Do Minerals Come From?• Occur freely in nature (rivers, lakes, oceans, topsoil,
under earth’s surface)
• Found in root systems of plants and in body structures of animals that consume plants and water
• Best sources of minerals are animal products (because they are more concentrated in animal tissues than in plants)
Functions of Minerals
• Provide structure in formation of bones & teeth
• Maintain normal heart rhythm, muscle contractility, nerve conduction, & acid-base balance of body fluids
• Regulatory role in cellular metabolism
• Part of enzymes & hormones that modify & regulate cellular activity
• Involved in catabolism & anabolism of nutrients
• Body’s most abundant mineral (1.5 to 2.0% of body mass; 1400 g)
• Ca combines with P to form hydroxyapatite, the crystalline structure of bones and teeth
• Ionized, Ca serves these functions:• Muscle contraction• Transmission nerve impulses• Activation of enzymes• Blood clotting• Fluid movement across membranes
Calcium
Osteoporosis• When calcium is deficient, bones
“give up” their calcium to try & restore deficit
• Bones become hollow or porous leading to breaks & fractures
• Hormone estrogen linked to osteoporosis– b/c estrogen enhances Ca
absorption, a decrease in estrogen no longer offers a protective effect
Osteoporosis:Bone Disease of Epidemic Proportions
• 1.5 million fractures yearly• 500,000 spinal fractures• 230,000 hip fractures
• Each year, 1.3 million osteoporetic women will fracture one or more of their bones
• About 1 of 6 older men & 1 of 3 older women will sustain hip fractures (death will occur in 20%)
• Often, x-rays don’t detect the disease until bone loss reaches 30 to 50% of its total mineral content!
Progressive Disease
• 30-50% bone loss by age 70 y
• Shrinkage of spinal vertebrae
Who Gets the Disease?
• By age 50:– Men lose about 0.4% bone each year– In women, the loss is about 0.8% starting at age 35
(double the loss 15 years sooner!)
• During menopause, bone loss accelerates to between 1% to 3% each year. Thus, by age 60, a woman can lose about 15% of her bone mass, and by age 70, bone loss can be as much as 30%
Where Does The Bone Loss Occur?• Most occurs in the vertebrae
– person shrinks in stature by up to 6 inches from age 45-50 to age 70
• The “spongy” bone (trabecular bone) loses its mineral content, causing the bone to crumble. The inside of the bone becomes honeycombed (like a beehive) and porous
CALCIUM AND EXERCISE HELPS
• Exercise -weight bearing help– weight training important for “bone fitness”
• 1200-1500 mg Calcium daily• Sardines, pink salmon, ricotta
cheese, dried figs• Calcium carbonate & calcium
citrate can help• Meat, salt, coffee, alcohol
inhibit Ca absorption
• Excessive intake increases fluid volume and peripheral vascular resistance– sodium-induced hypertension (occurs in 1/3 of individuals
with hypertension in U.S. and Japan)
• Recommended level = 1100 to 3300 mg/day – average in U.S = 3000 to 7000 mg/day– amount actually needed = 500 mg/day
• Sodium plentiful in table salt, MSG, soy sauce, condiments, canned foods, baking soda, baking powder
Sodium: How Much is Enough?
Vitamins and minerals do not appear to have any ergogenic value in amounts beyond the
RDA. Amounts greater than RDA probably does
not improve performance.
Vitamins & Minerals: The Bottom Line