carbs and energy:

carbs dietary importance

classes of carbs

carbs

monosaccharides

known as dextrose. primary energy source - circulates in the blood (BGL's). primarily comes from starch breakdown - may come from corn syrup or processed foods

known as fruit sugar - found in fruit and honey. sweetest sugar of the simplest sugars. high fructose corn syrups are used in processed foods, canned foods, frozen foods, soft drinks

not usually found as a monosaccharide in the diet. derived from lactose digestion. lactose = milk sugar: glucose and galactose

polysaccharides: complex carbs composed of many sugar units

significant in the diet. complex structure causes starch: break down more slowly (what we want), supply energy over a longer period of time than simple sugars. found in: grains (flour, bread, cereal, pasta), legumes (beans, pasta), vegetables (potatoes, rice, corn)-especially of the root variety, some fruit

not a dietary carb. our stored form of glucose. produced in the liver and muscle tissue: liver glycogen: increases blood glucose levels (BGL's) when low, muscle glycogen: used for contraction

not an energy source. known as cellulose in plants. humans cannot digest: lack digestive enzymes. health benefits: cardiovascular disease, GI problems, diabetes

nutritive sweeteners contribute to total caloric intake -provide 2-3kcal/g. sugar alcohols (sorbitol, mannitol, xylitol). benefits: absorption (sugar alcohols are absorbed more slowly than glucose, better for individuals who cannot tolerate high blood sugar -diabetes), decreased dental caries (cavities) because bacteria can't digest it

sugar alcohol: alcohol form of sucrose. common in candy, gum, beverages

sugar alcohol: alcohol form of mannose

sugar alcohol: alcohol form of xylose

no notable caloric intake. artificial sweeteners in food-ex's: aspartame (nutrasweet, equal), saccharin (sweetnlow), stevia, splenda

an indigestible carb. serves separately as a body regulatory agent. important in health promotion and disease prevention. all work the same by absorbing water: pectins, gums, mucilages

dietary fiber found in plant fruit and benefits to lower cholesterol

dietary fiber found in oats, legumes, and barley. functions to slow digestion and glucose absorption

dietary fiber found in psyllium seeds and flaxseeds and function to retain water

fats: can convert excess carbs into adipose tissue for when not in a well-fed state. solid fats = animal fats. plant-based fats = liquid = oils

active engagement in behaviors or programs that advance positive well-being. involves a balanced diet

the food that we eat. includes how the body uses it

takes scientific knowledge to govern nutrient requirements: growth, activity, reproduction, maintenance

look-fors for signs of proper nutrition:

categories of nutrients:

nutrients that must be obtained from food - can't be made in the body

nutrients that can be made in the body

nutrients that can yield energy in the body, like ATP

these types of nutrients are for energy

these types of nutrients are for tissue building

these types of nutrients are for regulation and control

functions of nutrients

the sum of all body processes inside living cells that sustain life and health - all our chemical reactions

individual nutrients have many specific metabolic functions, including primary and supporting roles. no nutrient ever works alone

dietary ___ from diet: sugars and starches. primary and preferred source of fuel for heat and energy. provides 4kcal/g. glycogen. energy source nutrient

glycogen: the body's back-up store of glucose. stored in the liver and muscle tissue. form of quick energy. NOT dietary - we make it in body. dietary intake: 45%-65% of total kilocalories per gov't recommendations but others disagree

dietary source of ___ - animal and plant sources. secondary form of heat and energy. provides 9kcal/g. adipocytes (fat cells): storage form of fat. dietary intake: 20-35% of total kilocalorie per govt recommendation. energy source nutrient

*not a preferred source of energy because it does so much else. only source of energy when supply from carbs and fats is low. provides 4kcal/g. 10-35% of total kcals per govt. primary functions: support (structural proteins), movement (contractile-actin/myosin proteins), transport, buffering, metabolic regulation: enzymes, coordination and control: hormones, defense: antibodies. energy source nutrient

tissue building nutrient. amino acids: building blocks of proteins. necessary for building and repairing body tissues: organs, muscles, cells, blood proteins

tissue building nutrient. vitamins: some contribute to tissue building - collagen: requires vitamin C*. minerals- ex's: calcium - calcium bone salts in bone matrix. iron: component of hemoglobin

tissue building nutrient. phosopholipids, glycolipids, and cholesterol are the major fats in the bilayer of the cell membrane

regulation and control nutrient. vitamins can function as coenzymes - assist enzymes in governing a chemical reaction during cell metabolism. many B-complex vitamins function as coenzymes (niacin, riboflavin). minerals (come from the earth) also serve as coenzyme factors. ex's: magnesium, zinc, and manganese

regulation and control nutrient. water - essential base for all metabolic processes. fiber - regulates passage of food material through GI tract

obtained from a varied diet. balance of 6 nutrients: carbohydrates, fats, proteins, vitamins, minerals, and water. nutrients should be balanced: to cover variations in health and disease and to provide reserve supplies (glycogen, etc. for a time when not in a well-fed state)

improper or insufficient diet. insufficient intake of fruits, vegetables, and dairy. improper: increased intake of saturated fats, alcohol, sugar. nutrient and energy intake insufficient*. can be 1 thing missing even if functioning normally - having even 1 missing constitutes as this. this is a general category. may lead to greater risk of physical illness, compromised immunity (bc immune system is energy dependent - ATP), limited physical activity, immune system function, and mental activity

subcategory of malnutrition. nutritional reserves are depleted (no glycogen, body fat, etc). nutrient and energy intakes are NOT enough to meet daily need or added metabolic stress

too much. another category of malnutrition. excess nutrient and energy intake over time. produces harmful gross body weight. excessive amounts of nutrient supplements over time - fat soluble vitamins, etc

food and nutrient guides help us to plan a balanced diet according to individual needs and goals. there is controversy surrounding the "optimal diet" - everyone has their own idea

published by the National Academy of Sciences. standards are updated every 5-10 years. includes recommendations for each gender and age group - focus of the standards is to maintain optimal health

food guidance system est. in 2011. goal is to promote: variety, proportionality, moderation, gradual improvements. participants are encouraged to customize the plan by entering their sex, age, weight, activity, etc

with alternate dietary plans, there is much debate regarding the optimal diet. it's possible that different individuals have different requirements

carbohydrate foods provide practical energy (calorie) sources because of their availability, relatively low cost, and storage capacity. carbohydrate structures vary from simple to complex to provide both quick and extended energy for the body

carbohydrates relation to energy

classes of carbohydrates

simple sugar-easily absorbed from digestive tract. simple carb - glucose, fructose, galactose. all contain 6 carbons. C6H12O6

glucose = 6 carbon ring

double sugar - simple sugar formed by bonding of 2 monosaccharides. simple carb: sucrose = glucose and fructose; lactose = glucose and galactose; maltose = glucose and glucose

glucose and fructose (table sugar)

glucose and galactose (milk sugar)

glucose and glucose (malt sugar). intermediate produced in the digestion of starch

complex sugar. formed by bonding of many monosaccharides. starch, glycogen, dietary fiber. all start with glucose

most significant polysaccharide in the diet. whole grains retain the bran (fiber) layer, inner germ, and endosperm, including the nutrients naturally found in the plant. enriched grains are refined grains that have nutrients added back to them after they were taken out. enriched grains = not great. whole grains-what we want

some high starch foods have a high glycemic index. glycemic index (GI) is a relative ranking of carbs in foods according to how they affect BGLs. low end of GI will raise BGLs slowly and won't cause a surge

nutritive sweeteners

nonnutritive sweeteners are artificial sweeteners in food

dietary fiber is an indigestible carbohydrate that serves separately as a body regulatory agent. it's important in health promotion and disease prevention. 3 types important in human nutrition:

dietary fiber that remains undigested in the GI tract and provides bulk to a diet. bulk helps move the food mass through the intestine. ex: stems, leaves of vegetables; coverings of seeds and grains

dietary fiber that absorb water and swell to a larger bulk. ex's: pectins, gums, mucilages, algal substances

dietary fiber that is the only noncarbohydrate type of dietary fiber. woody parts of plants (broccoli stems and fruits with edible seeds). functions: antioxidants* and lower cholesterol

dietary fiber is divided into 2 groups based on solubility

cellulose, lignin

gums, mucilages, pectins

many health organizations recommend increasing intake of dietary fiber. 38g/day for men. 25g/day for women

sudden increases in dietary fiber can result in gas, bloating, constipation. excessive amounts of it can trap small amounts of minerals and prevent absorption into the GI tract

basic fuel supply - energy for physical activities and all work of body cells.

reserve fuel supply - provided by glycogen; maintains normal BGL

liver: glycogen reserves protect cells from depressed metabolic function. protein and fat sparing: carbs regulate proteins and fat metabolism. if carbs are plentiful, proteins and fats are spared for other functions in the body

dietary fat supplies essential body tissue needs, both as an energy fuel and a structural material. foods from animal and plant sources supply distinct forms of fat that affect health in different ways. excess dietary fat may be a negative risk factor in overall health

dietary importance of fats:

source of essential fatty acids - eicosanoids.

concentrated fuel source in human energy system (9kcal/g):

physical properties of fats

classes of fats

filled or "saturated" with hydrogen (look at C bonds-all have 4); look for single bonds - ONLY single bonds! solid at room temperature. found in higher amounts of animal fats

NOT completely filled with hydrogen-look for double bonds in hydrocarbon chain. liquids at room temperature. less heavy, less dense. monounsaturated: one unfilled spot (one double bond). unfilled=missing H so that's where double bond will be. sources: oils (peanut, olive, canola, nuts-almonds, avocados). polyunsaturated: two or more unfilled spots (multiple double bonds). sources: vegetable oils (safflower, sunflower, corn)

remember essential means nutrient must be consumed in the diet. polyunsaturated fatty acids. source of essential fatty acids: two acids- linoleic acid (an omega-6) and alpha-linolenic acid (an omega-3). important in tissues strength, cholesterol metabolism, and cardiovascular health

fats dietary reference intakes: linoleic acid - 17g/day for men, 12g/day for women. linolenic acid- 1.6g/day for men, 1.1g/day for women. current US diet at ratio of 8:1 to 12:1. recommended ratio of 2:1 to 3:1

hydrogen bonds are on the same side of the double bond. found in naturally occurring fatty acids

trans=across. look for no trans fat on foods for safer options. hydrogen bonds are on the opposite side of the double bond. occurs in industry- vegetable oils are partially hydrogenated (addition of hydrogen), promotes cardiovascular disease

majority of dietary fats. structure: glycerol backbone, three fatty acids (differences in chain length and saturation)

triglyceride derivative: third fatty acid replaced by phosphate group. partially hydrophobic, partially hydrophilic. phosphate group: hydrophilic. fatty acid tails: hydrophobic. major constituents in cell membranes and organelles. allow transport of fats through bloodstream - form lipoproteins

subgroup of steroids. phyosterols: produced by plants. zoosterols: produced by animals, ex: cholesterol

functions: component of cell membranes. not a fat. a fat-related compound: from animal foods (egg yolks, organ meat: liver, kidney). endogenous cholesterol: primarily synthesized in the liver and other organs. guidelines now state it's not a nutrient of concern for overconsumption because the liver makes it anyway

complex lipids: transport fats/cholesterol in blood. 2 major types: low density ___ (LDLs) and high density ___ (HDLs)

carry fat and cholesterol to the cells. if this number is high, probably consuming too many-a lot of fried foods, etc. promotes cardiovascular disease. "bad cholesterol"

carry cholesterol from the body tissues to the liver for metabolism. "good cholesterol". high number of this means getting rid of excess cholesterol and triglycerides for removal from the body. this is the good one to have a high number in

functions of fat in foods. fat in foods provide: energy (9kcal/g) and essential nutrients:

functions of fat in the body. adipose tissue (protects organs and helps regulate temperature) and cell membrane structure (phospholipids and cholesterol form part of cell membrane; helps transport nutrients across cell membranes)

food sources of fat:

primarily saturated fat and cholesterol (meat, dairy, egg yolks)

supply mono and polyunsaturated fats. sources: vegetable oils (olive, peanuts, safflower) and supply saturated fats. sources: coconut and palm oil

commercial fat products raise health concerns. cis form. trans form. food industry now offers trans-free products - are these healthy?

digestion of fats

healthy diet guidelines (govt given):

each protein is composed of hundreds of amino acids. amino acids are the basic building material for proteins. amino acids form unique chain sequences to form specific proteins. when protein foods are eaten, proteins are broken down into amino acids. amino acids are reassembled in the body to form a variety of proteins

classes of amino acids

class of amino acids that body cannot manufacture in sufficient quantity. need from diet

class of amino acids that body can synthesize from indispensable. can make them

class of amino acids normally synthesized but some health conditions may require dietary intake

protein balance - normally intake and output are in equilibrium. catabolism: breakdown of proteins into amino acids. anabolism: resynthesis of proteins from the amino acids. nitrogen balance (intake = excretion): provides an indication of how well tissues are maintained. 1g of nitrogen excreted for every 6.25g of nitrogen from diet and metabolism

body stores more than it excretes. seen in periods of growth, pregnancy, lactation, or following a severe illness

body takes in less than it excretes. from inadequate protein intake. body will break down tissues to supply amino acids

functions of protein

function of protein that makes it the fundamental structural material of every cell. proteins comprise bulk of: muscles, internal organs, brain, nerves, blood plasma. protein repairs worn out, wasted, or damaged tissue

function of protein. plasma proteins attract water, resulting in maintenance of normal circulation. keeps water in bloodstream where need it

function of protein. proteins have a unique structure to act as buffering agents --> amphoteric (something has the ability to act as an acid or a base). H ions make us acidic. NH2 group can act as a base - can accept H out of the blood and raise pH

function of protein. enzymes: cellular enzymes, digestive enzymes (amylases, lipases, proteases - break down proteins); transport agents: lipoproteins, hemoglobin; hormones: insulin and glucagon

function of protein. immune system defends against disease and infection. wbcs and antibodies

function of protein. may provide body fuel if the supply of carbohydrates and fat is insufficient for needs. less efficient

food sources of protein that contain all 9 indispensable (essential) amino acids. animal sources: eggs, milk, cheese, meat, fish, poultry. plant source: soy

food sources of protein that lack one or more indispensable amino acids. plant origin foods: grains, legumes, nuts, seeds, fruits and vegetables

vegetarian diets must combine foods to cover all amino acid needs. different types:

benefits of vegetarian diets:

digestion of proteins: in mouth (mechanical digestion), stomach (protein digestion by proenzymes-zymogens; hydrochloric acid - denatures proteins, converts pepsinogen into pepsin; pepsin -proteins broken down to short chain polypeptides; renin - only in infancy and childhood); small intestine pancreatic secretions:

digestion of proteins in small intestine intestinal secretions:

common in developing countries due to lack of high-quality protein sources. Kwashiorkor: common in children between ages of 18-24 months who are rapidly weaned and switched to a diet of mostly carbohydrates and little protein. characterized by edema in lower limbs and bloated abdomen. marasmus: chronic form of protein deficiency: starvation; emaciated appearance (skin and bones appearance)l little or no body fat

usually also means excess fat intake as animal proteins are high in fat. if an individual consumes mostly protein, there is little room for other healthy foods which contain vitamins, minerals, and fibers. additional proteins undergo deamination (remove nitrogen group --> ammonia --> urea --> urine). nitrogen converted to urea. extra burden on kidneys

proteins recommended dietary allowance (RDAs): relate to sex, age, weight. highest at birth and slowly decline into adulthood. 10-35% of total caloric intake from protein (kids and adults). men and women: 0.8g/kg of high-quality protein per/kg of desirable weight per day. calculation:

70kg (~150lb) adult

70kg x 0.8g/kg = 56 g/day.

DRI: assumes individual consumes 2200 kcal.day, based on recommendation. 2200 kcal x0.10-0.35 = 220-770 kcal/day from protein. 220-770 kcal, 4kcal/g = 55-192.5 g/day of protein