major functions of water in the body

• carries nutrients and waste products throughout the body
• maintains the structure of large molecules such as proteins and glycogen
• participates in metabolic reactions
• serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small molecules so that they can participate in metabolic activities
• acts as a lubricant and cushions joints and inside the eyes, the spinal cord, and, in pregnancy, the amniotic sac surrounding the fetus in the womb
• aids in the regulation of normal body temperature, as the evaporation of sweat from the skin removes excess heat from the body
• maintains blood volume

water balance

• the accounting of water inflows, outflows, and storage changes within a system over time

major water sources (water in)

• fluids (2000 ml - 8 cups)
• water content in food (500 ml - 2 cups)
• water produced from metabolism (300 ml - 1.25 cups)

beverages (550 - 1500 mL)

foods (700 - 1000 mL)

metabolism (200 - 300 mL)

total: 1450 - 2800 mL

body's major routes of water loss (water out)

insensible losses

• skin perspiration (750 ml - 3 cups)
• lung respiration (300 ml - 1.25 cups)
• feces (100 ml - 0.4 cup)

sensible losses

• urine (1650 ml - 6.75 cups)

kidneys (urine) (500 - 1400 mL)

skin (sweat) (450 - 900 mL)

lungs (breath) (350 mL)

GI tract (feces) (150 mL)

total: 1450 - 2800

moderate alcohol consumption for men

• less than or equal to 2 drinks (per day)

moderate alcohol consumption for women

• less than or equal to one drink (per day)

one drink when referring to an alcoholic beverage

½ oz pure ethanol

• 5 oz of wine
• 10 oz of wine cooler
• 12 oz of beer
• 1 ½ oz of liquor (80 proof whisky, scotch, rum, or vodka)

several factors that affect the body's ability to metabolize alcohol

• rate of stomach emptying
• intake of certain drugs
• type of beverage consumed

rate of stomach emptying affect on alcohol metabolization

• alcohol needs no digestion, quickly absorbed across the walls of an empty stomach, reaching the brain within a few minutes
• when stomach is full of food – alcohol has less chance of touching the walls and diffusing through → influence on the brain is slightly delayed
• carbohydrate snacks slow alcohol absorption, high-fat snacks slow peristalsis, keeping alcohol in the stomach longer

alcohol metabolization: women vs men

• women produce less alcohol dehydrogenase enzyme in the stomach → more alcohol reaches the intestine for absorption into the blood stream
• absorb more alcohol than men of the same size drink, more likely to become intoxicated on alcohol than men

type of alcohol consumed, effect on alcohol metabolization

• certain drinks have higher alcohol content than others
• different beverages influence gastric emptying and absorption rate
• carbonated drinks increase gastric pressure, speed gastric emptying (higher and earlier peak BAC)
• higher alcohol content / hard alcohol (higher concentration of ethanol, slower initial absorption but progresses quickly once in small intestine)
• diluted alcohol (reducing gastric irritation, speed up gastric emptying) – faster absorption than undiluted spirits
• sugary drinks – can slow the absorption of alcohol

potential health benefits associated with moderate consumption

• reduces blood clotting
• increases HDL
• reduces inflammation (CRP)
• improved insulin sensitivity
• lower dementia / Alzheimer's disease risk

polyphenols

• red wine, dark beer
• antioxidant effect

detrimental effects of alcohol when consumed in excess

• dehydration, loss of important minerals
• malnutrition (diet quality declines as alcohol consumption increases)
• displacing other important nutrients
• arthritis
• bone loss
• cancer
• fetal alcohol syndrome
• heart disease
• hyperglycemia
• hypoglycemia
• infertility
• kidney disease
• liver disease
• lung disease
• nerve disorders
• obesity
• psychological disturbances (depression, anxiety, insomnia)

MEOS (Microsomal Ethanol-Oxidizing System)

• enzyme system that metabolizes both alcohol and several other types of drugs
• handles about ⅕ of the total alcohol a person consumes
• high blood concentrations, repeated exposures to alcohol – alcohol stimulates synthesis of enzymes in the MEOS
• results in more efficient alcohol metabolism and tolerance to its effects
• drinking and using drugs at the same time – alcohol is prioritized for metabolism, drug more slowly (drug effect builds up, greatly amplified result)

Cirrhosis

• advanced liver disease in which liver cells turn orange, die, and harden, permanently losing their function (often associated with alcoholism)
• fatty infiltration of the liver (most advanced stage)
• 2nd leading cause for liver transplant
• 50% chance of death within four years

Wernicke-Korsakoff Syndrome

• a neurological disorder typically associated with chronic alcoholism and caused by a deficiency of the B vitamin thiamin (also called alcohol-related dementia)
• syndrome characterized by paralysis of eye muscles, poor muscle coordination, impaired memory, and damaged nerves

macronutrients

• required in gram quantities
• structure - polymer
• some are essential
• provide calories

carbs, lipids, protein

micronutrients

• required in mg quantities
• structure - individual molecule
• all are essential
• provide no calories

vitamins and minerals

fat-soluble vitamins

dissolve in fat or organic solvents

• vitamin A
• vitamin D
• vitamin E
• vitamin K

how solubility affects absorption: fat-soluble vitamins

• must first enter the lymph and then enter the blood

how solubility affects transport: fat-soluble vitamins

• require transport proteins to move around

how solubility affects storage: fat-soluble vitamins

• held in fatty tissues and the liver until needed

how solubility affects excretion: fat-soluble vitamins

• remain in fat storage sites in the body rather than being excreted
• more likely to reach toxic levels when consumed in excess

water-soluble vitamins

dissolve in water

• found in the watery compartments of food
• B vitamins
• vitamin C

how solubility affects absorption: water-soluble vitamins

• directly into the blood

how solubility affects transport: water-soluble vitamins

• travel freely

how solubility affects storage: water-soluble vitamins

• circulate freely in water-filled parts of the body

how solubility affects excretion: water-soluble vitamins

• kidneys detect and remove excess in urine
• lower risk of toxicity
• greater risk of deficiency if intake is inadequate

toxicity: water-soluble vitamins

• possible to reach toxic levels when consumed from supplements

toxicity: fat-soluble vitamins

• likely to reach toxic levels when consumed from supplements

requirements: water-soluble vitamins

• needed in frequent doses (perhaps 1 to 3 days)

requirements: fat-soluble vitamins

• needed in periodic doses (perhaps weeks or even months)

B vitamins

• thiamin (B1)
• riboflavin (B2)
• Niacin (B3)
• B6
• folate
• B12

thiamin, major food sources

• whole-grain, fortified, or enriched grain products
• pork
• moderate amounts in all nutritious foods

riboflavin, major food sources

• milk products (yogurt, cheese)
• whole-grain, fortified, or enriched grain products
• liver

niacin, major food sources

• milk
• eggs
• meat / poultry / fish
• whole-grain, fortified, and enriched grain products
• nuts and all protein-containing foods

vitamin B6, major food sources

• meat / fish / poultry
• potatoes
• starchy vegetables
• legumes
• noncitrus fruits
• fortified cereals
• liver
• soy products

folate, major food sources

• fortified grains
• leafy green vegetables
• legumes
• seeds
• liver

vitamin B12, major food sources

• foods of animal origin (meat, fish, poultry, shellfish, milk, cheese, eggs)
• fortified cereals

thiamin, major deficiency disease

• beriberi
• wernicke-korsakoff syndrome (related to heavy alcohol consumption with limited food consumption)

Wernicke-Korsakoff Syndrome

• severe thiamin deficiency associated with heavy alcohol consumption with limited food consumption (or poor diet)
• ^alcohol diminishes thiamin absorption, increases thiamin excretion
• characterized by muscle weakness, edema, or both

riboflavin, major deficiency disease

• ariboflavinosis

ariboflavinosis

• glossitis (inflammation of the tongue)
• cheliosis (cracks at corner of mouth)
• occurs within two months, rarely in isolation
• risk factors: alcoholic use disorder, phenobarbital use, no milk intake (marginal)

niacin, major deficiency disease

• pellagra

pellagra

• characterized by diarrhea, dermatitis, dementia, and eventually death
• affects skin, GI tract, CNS (worsened by sun exposure)
• caused by: meat (fatback, protein poor), maize (corn as main staple in diet), molasses
• occurs in 50-60 days

B6, major deficiency disease

• microcytic hypochromic anemia

microcytic hypochromic anemia

• blood cells are abnormally small
• convulsion, depression, confusion
• reduced immune response
• peripheral nerve damage
• seborrhetic dermatitis (chronic inflammatory skin condition)

folate, major deficiency disease

• megoblastic anemia

megoblastic anemia

• abnormally large, immature, and dysfunctional red blood cells
• decreased DNA synthesis, cells fail to divide
• additional folate may also mask an underlying vitamin B12 deficiency

vitamin B12, major deficiency disease

• pernicious anemia

pernicious anemia

• due to low absorption rather than low intake
• looks like megoblastic anemia (anemia due to low folate - abnormally large, immature, and dysfunctional red blood cells)

major uses of vitamin C in the body

• antioxidant
• collagen formation (connective tissue that keeps skin intact)
• neurotransmitter formation
• hormone formation
• enhances immune function (protects WBCs from damage)
• reducing agent (donates electrons to metals which enhances iron absorption)

signs and symptoms of vitamin C deficiency

scurvy

• caused by lack of this vitamin for 20-40 days
• fatigue, pintpoint hemorrhages (petichiae)
• bleeding gums, poor wound healing, fractures

signs and symptoms of vitamin C toxicity

GI distress

• nausea, abdominal cramps, diarrhea

may increase risk of iron overload in genetically predisposed men

interference with some diagnostic medical tests

levels achieved with supplementation

major food sources of vitamin C

citrus fruits

• oranges, orange juice

berries

• strawberries

some vegetables

• red pepper, broccoli

role of vitamin A in the body

• vision
• maintenance of cornea, epithelial cells, mucuos membranes, skin
• bone and tooth growth
• reproduction
• immunity

effects of vitamin A deficiency

• night blindness
• corneal drying (xerosis)
• triangular gray spots on eye (Bitot's spots)
• softening of the cornea (keratomalacia)
• corneal degeneration and blindness (xerophtalmia)
• impaired immunity (infectious diseases)
• plugging of hair follicles with keratin
• forming white lumps (hyperkeratosis)

effects of vitamin A toxicity (chronic)

• hypervitominosis A
• increased activity of osteoclasts causing reduced bone density
• liver abnormalities
• birth defects

effects of vitamin A toxicity (acute)

• blurred vision
• nausea
• vomiting
• vertigo
• increase of pressure inside skull, mimicking brain tumor
• headaches
• muscle incoordination

(carotenoids - can turn skin a yellow-orange color)

major foods sources of vitamin A (performed) and beta-carotene

retinol

• fortified milk
• cheese
• cream
• butter
• fortified margarine
• eggs
• liver

beta-carotene

• spinach and other dark green, leafy vegetables
• broccoli
• deep orange fruits (apricots, cantaloupe)
• vegetables (squash, carrots, sweet potatoes, pumpkin)

uses of vitamin D in the body

• mineralization of bones (raises blood calcium and phosphorus by increasing absorption from digestive tract, withdrawing calcium from bones, stimulating retention by kidneys)
• calcium homeostasis
• bone growth and maintenance
• cell differentiation

necessary for calcium absorption

effects of vitamin D deficiency

rickets (in children)

• inadequate calcification, resulting in misshapen bones (bowing of legs); enlargement of ends of long bones (knees, wrists); deformities of ribs (bowed, with beads or knobs); delayed closing of fontanel, resulting in rapid enlargement of head; lax muscles resulting in protrusion of abdomen; muscle spasms

osteomalacia or osteoporosis in adults

• loss of calcium, resulting in soft, flexible, brittle, and deformed bones
• progressive weakness
• pain in pelvis, lower back, and legs

effects of vitamin D toxicity

• hypervitaminosis D
• elevated blood calcium
• calcification of soft tissues (blood vessels, kidneys, heart, lungs, tissues around joints)

major food (and non-food) sources of vitamin D

• synthesized in the body with the help of sunlight
• fortified milk, margarine, butter, juices, cereals, and chocolate mixes
• veal, beef, egg yolks, liver, fatty fish (herring, salmon, sardines), and their oils

role of vitamin E in the body

• antioxidant (stabilization of cell membranes, regulation of oxidation reactions, protection of polyunsaturated fatty acids and vitamin A)

prevents damage from free radicals

effects of vitamin E deficiency

• red blood cell breakage (hemolytic anemia / erythrocyte hemolysis)
• nerve damage

effects of vitamin E toxicity

• augments the effects of anticlotting medication (ie. inhibits vitamin K metabolism)
• hemorrhaging (uncontrolled bleeding, reudces blood clotting)

major food sources of vitamin E

• polyunsaturated plant oils (margarine, salad dressings)
• dark green, leafy vegetables (spinach, turnip greens, collard greens, broccoli)
• wheat germ
• whole grains
• liver
• egg yolks
• nuts
• seeds
• fatty meats

major role of vitamin K in the body

• synthesis of blood-clotting proteins and bone proteins (bone health)

effects of vitamin K deficiency

• hemorrhaging
• bone / hip fractures

effects of vitamin K toxicity

• not common
• high doses can reduce effectiveness of anticoagulant drugs (used to prevent blood clotting)

food and non-food sources of vitamin K

• bacterial synthesis in the digestive tract (although not enough to fully meet needs)
• liver
• dark green, leafy vegetables
• cabbage-type vegetables
• milk

antioxidant

substances that significantly decrease the adverse effects of free radicals on normal physiological functions

vitamins that act as antioxidants in the body

vitamin C, vitamin E, beta-carotene (vitamin A)

minerals

• inorganic elements
• elements present in the human body
• not destroyed by heat, air, acid, light
• classified as macro, micro / trace, ultra-trace

vitamins

• organic compounds (made by plants or animals)
• broken down by heat, air, acid, light
• facilitate energy-yielding chemical reactions
• some act as coenzymes *mostly act as helpers in chemical reactions (coenzymes), supporting metabolism, immunity, and cell function

major minerals

• essential mineral nutrients the human body requires in relatively large amounts (greater than 100 milligrams per day) – sometimes called macrominerals.

trace minerals

• essential mineral nutrients the human body requires in relatively small amounts (less than 100 milligrams per day); sometimes called microminerals.

role of calcium in the body

• mineralization of bones and teeth (ie. bone structure, development, maintenance)
• involved in muscle contraction and relaxation, nerve functioning, blood clotting, blood pressure

factors that enhance the absorption of calcium

• vitamin D
• stomach acidity

factors that limit the absorption of calcium

• deficiency of vitamin D
• fiber
• protein
• sodium
• caffeine

hormones needed to maintain blood calcium levels

• parathyroid hormone
• calcitonin

parathyroid hormone

• hormone from the parathyroid glands that regulates blood calcium by raising it when the levels fall too low

calcitonin

• hormone secreted by the thyroid gland that regulates blood calcium by lowering it when levels rise too high

food sources of calcium

• milk, yogurt, cheese
• kale, collard, mustard greens
• canned fish with bones
• calcium-fortified foods

effects of calcium deficiency

• stunted growth in children
• bone loss (osteoporosis) in adults
• tetany

also associated with:

• hypertension
• colon cancer
• obesity or higher body weight

risk factors for development of osteoporosis

non-modifiable

• female
• older age (over 50)
• small frame
• caucasian, asian, or hispanic/latinx
• family history of osteoporosis
• personal history of fractures
• estrogen deficiency in women (amenorrhea or menopause in women, especially early or surgically induced)

modifiable

• sedentary lifestyle
• diet inadequate in calcium and vitamin D
• diet excessive in protein, sodium, caffeine
• cigarette smoking
• alcohol abuse
• low body weight
• certain medications, such as glucocorticoids, aluminum-containing antacids, and antiseizure drugs

roles of physical activity and calcium intake

maintains and improves bone health, density, and strength

major roles of phosphorus in the body

• mineralization of teeth and bones
• part of every cell
• important in genetic material
• part of phospholipids
• used in energy transfer and in buffer systems that maintain acid-base balance

food sources of phosphorus in the diet

• widely distributed in foods – meat, poultry, fish, eggs, milk, milk products, nuts, legumes, cereals, grains
• soft drinks (phosphoric acid)
• coffee, tea
• food additives

*foods derived from animals

role of magnesium in the body

• bone mineralization
• building of protein
• enzyme action
• normal muscle contraction
• nerve impulse transmission
• maintenance of teeth
• functioning of immune system

major food sources

• nuts
• legumes
• whole grains
• dark green vegetables
• seafood
• chocolate
• cocoa

electrolyte

all mineral salts whose ions dissolve in water

list the 3 major electrolyte minerals

• sodium
• potassium
• chloride

role of sodium in the body

• electrolyte
• participates in nutrient absorption / transport
• assists in nerve impulse transmission
• fluid, pH, electrolyte balance

effects of excessive intake of sodium

• hypernatremia
• increased calcium excretion
• kidney stone formation
• high intake accompanied by lack of water
• symptoms: edema, acute hypertension
• UL 2300 mg

major food sources of sodium

• table salt
• soy sauce
• moderate amounts in meats, milk, breads, and vegetables
• large amount in processed foods

processed foods (75%)

salt added at table / in cooking (15%)

naturally occurring in foods (10%)

role of potassium in the body

• maintains normal fluid and electrolyte balance
• facilitates many reactions
• supports cell integrity
• assists in nerve impulse transmission and muscle contractions

effects of inadequate intake of potassium

• irregular heartbeat
• muscular weakness
• glucose intolerance

major food sources of potassium

• all whole foods: meats, milks, fruits, vegetables, grains, legumes
• major sources in the adult diet: milk, potatoes, coffee, tomatoes, orange juice

DASH (Dietary Approaches to Stop Hypertension) diet

• key foods: fruits, vegetables, low fat dairy, nuts
• key components: high in Ca, K, Mg ; low in Na ; low fat, sat fat ; high fiber

who might benefit from DASH diet

• people with hypertension, high blood pressure, type 2 diabetes, high cholesterol, looking to lose weight, etc.

major role of chloride during digestion

formation of gastric acid (HCl)

major functions of iron in the body

component of several body proteins

• hemoglobin in red blood cells (O2 transport)
• myoglobin in muscle cells (O2 storage)

enzyme cofactor

availability of iron from plant vs. animal sources

• heme iron – contained in hemoglobin, myoglobin of meat, fish, poultry
• non-heme iron – present in vegetables, grains, and supplements
• only foods derived from animal flesh provide heme, but they also contain nonheme iron (which is why heme iron sources tend to be more bioavailable)
• heme accounts for about 10% of the average daily iron intake, but it is well absorbed (about 25%); nonheme iron accounts for the remaining 90% but it is less well-absorbed (about 17%)

role of zinc in the body

• part of many enzymes
• associated with the hormone insulin
• involved in making genetic material and proteins
• immune reactions
• transport of vitamin A
• taste perception
• wound healing
• the making of sperm
• the normal development of the fetus

major food sources of zinc

• protein-containing foods: red meats, shellfish, whole grains; some fortified cereals
• legumes, nuts

consequences of a zinc deficiency

• stunted growth
• delayed sexual maturation
• impaired immune function
• hair loss
• eye and skin lesions
• loss of appetite (reduced sense of smell and taste)
• impaired vitamin A metabolism

genetic

• acrodermatitis enteropathica

effects of insufficient iodine intake

• underactive thyroid gland
• goiter
• limited mental and physical development in infants (cretinism)

effects of excess iodine intake

• underactive thyroid gland
• elevated TSH
• goiter

use of chromium in the body

• enhances insulin action and may improve glucose tolerance

relationship between chromium and diabetes

• deficiency causes a diabetes-like condition
• reduced risk of diabetes with increased intake (due to enhanced insulin action when consuming)

use of selenium in the body

• defends against oxidation (ie. prevents free radical formation, working indirectly as an antioxidant)
• regulates thyroid hormone

role of selenium in cancer protection

• increased incidence of several cancers in people living in areas with low soil selenium levels (correlation between deficiency and and higher cancer levels, but cause and effect are not 100% proven)

use of fluoride in the body

• strengthens teeth
• helps to make teeth resistant to decay
• increases bone mass

role of fluoride in preventing dental caries

• optimal levels of fluoride necessary to reduce incidence of dental carries, maintain integrity of skeletal tissue
• reduces amount of acid produced by plaque bacteria
• reduces acid solubility of tooth enamel
• promotes remineralization, slows demineralization

benefits of engaging in regular physical activity

improved

• cardiovascular health
• GI health
• immune function
• psychological health
• nutritional health
• sleep quality
• body composition / body density
• longevity

reduced risk of

• obesity
• diabetes (type 2)
• gallbladder disease
• cancer
• cardiovascular disease
• osteoporosis
• injuries
• severe anxiety and depression

components of fitness

• aerobic capacity
• muscle strength
• muscle endurance
• muscle power
• flexibility
• body composition

aerobic capacity

• the maximal capacity for oxygen consumption by the body during maximal exertion – reflects cardiovascular fitness

muscle strength

• the maximum force a muscle or muscle group can generate

muscle endurance

• the ability to sustain muscle contractions – over a continuum or relative forces

muscle power

• the explosive aspect of strength (the product of strength and velocity)

flexibility

• the range of motion in various joints

body composition

• the proportion of total body mass that exists in the form of Fat Mass (FM) and fat-free mass (FFM)

progressive overload principle

• a principle of training that states for a body system to improve, it must be worked at frequencies, durations, or intensities that increase by increments
• overload = an extra physical demand placed on the body; an increase in the frequency, duration, or intensity of an activity

use of glucose and glycogen as body fuels during exercise

• high carbohydrate diets enhance endurance by ensuring ample glycogen stores
• muscle glycogen is the primary fuel source for most intense activities
• can be depleted in 1-2 hours depending on intensity (and once depleted, can only work at around 50% of maximal capacity)

diet to minimize glucose depletion during exercise

• prior to exercise: high carb diets ensure more adequate source of dietary glucose to defend plasma glucose levels
• during exercise: benefits activities lasting more than an hour; sports bars (less than 10% sugar); energy bars
• post-exercise: replenish stores within 2 hrs of exhaustive activity

carbohydrate loading

strategy used by endurance athletes to maximize glycogen stores in body before prolonged exercise

• begin one week prior to event / competition
• gradually decrease training intensity / duration
• gradually increase CHO intake (70-80% kcal)
• can increase muscle glycogen stores 50-100%
• greater muscle glycogen = greater endurance potential
• beneficial for endurance events (> 90-120 mins)

the role of body fat during prolonged exercise

• primary fuel for prolonged low-intensity exercise
• fatty acids from storage converted to acetyl-CoA (and ATP) in mitochondria of muscle cells
• SM training effects:
• more mitochondria (mitochondrial density)
• more active mitochondrial enzymes
• greater ability to use fat as fuel
• higher lipolytic capacity
• 25-30% kcal from fat ideal for athletes

protein needs of an athlete

• minor source of fuel
• contributes around 5% of energy needs under most conditions
• 10-15% during endurance exercise, when glycogen stores are exhausted
• RDA based on needs of sedentary (0.8kg)
• used by athletes and sedentary individuals to build muscles and other lean tissues

protein used in muscle building

• synthesis of body proteins is suppressed during activity
• in hours of recovery following activity, protein synthesis accelerates beyond normal resting levels

protein needs of a sedentary person

• requires less protein to maintain basic bodily functions (athletes require more to support muscle protein synthesis, repair, and adaptation to training)

vitamins of concern for highly active people

• vitamin E
• vitamin C
• B vitamins ? (participate in many bioenergetic pathways, but do we need more with exercise?)
• choline ? (precursor to acetylcholine, SM neurotransmitter)

minerals of concern for highly active people

• iron
• calcium
• sulfur ? (sulfur-containing AAs are essential and interesting ex. physiologists)

reasons why female endurance athletes may be vulnerable to iron deficiency

• habitually low intakes of iron-rich foods
• high iron losses due to menstruation
• high demands of muscles for the iron-containing electron carriers of the mitochondria and the muscle protein myoglobin
• also – endurance activities temporarily increase the release of hepcidin, which limits iron absorption

increased risk if active female is vegetarian due to low bioavailability of iron in plant-based diet

hydration schedule for physical activity

• thirst is not a reliable indicator
• water best for activity less than 1 hr
• consume no more than 1 L / hr

when to drink

• 2 hr before activity – 2 to 3 c
• 15 mins before activity – 1 to 2 c
• every 15 mins during activity – 1 to 1 ½ c
• after activity – 2 to 3 c for each pound of body weight lost

need for electrolyte replacement

during activity, the need for water surpasses the need for any other nutrient

body relies on watery fluids as the medium for all life-supporting activities, and if it loses too much water, its well-being will be compromised

• water losses due to sweat, respiration
• helps regulate body temperature (keep cool)

ergogenic aid

• substances or techniques used in an attempt to enhance physical performance

why a nutritionally adequate diet is important long before a pregnancy is established

• both a woman and a man’s nutrition may affect fertility and possibly the genetic contributions they make to their children
• woman’s nutrition has the most direct influence on developing fetus

dietary recommendations pre-pregnancy

• mothers: nutritional adequacy (folate, Fe, Zn, Ca), appropriate body weight
• fathers: consume plenty of fruits and vegetables: vitamin C, abstain from alcohol, also maintain healthy body weight
• both should avoid ingesting harmful substances (cigarettes, drugs, alcohol, environmental contaminants)

stages of prenatal growth and development

• egg and sperm
• 3-8 weeks
• 9 weeks to birth

placenta

• the organ that develops inside the uterus early in pregnancy, through which the fetus receives nutrients and oxygen and returns carbon dioxide and other waste products to be excreted

critical period

• finite periods during development in which certain events occur that will have irreversible effects on later developmental stages; usually a period of rapid cell division

NTD (neural tube defects)

• malformations of the brain, spinal cord, or both during embryonic development that often result in lifelong disability or death

spina bifida

• one of the most common types of neural tube defects, characterized by the incomplete closure of the spinal cord and its bony encasement

the role of folate during the early stages of fetal development

• important in neural tube formation (prevents birth defects like spinal bifidia)
• DNA synthesis and cell division (rapid division of cells requires folate to produce DNA and RNA)
• birth defect prevention
• important in organ and tissue formation

relationship between maternal weight gain during pregnancy and infant birthweight

pre-pregnancy status

• underweight: higher risk of LBW, preterm, infant death
• overweight: higher risk of macrosomia, post term, NTDs

birth weight is the most reliable indicator of an infant’s health

(low body weight increases risk of dying in first year by 40x – more likely to experience complications during delivery, greater chance of having physical/mental birth defects)

later in life, SGA infants are more likely to develop type 2 diabetes, hypertension, high cholesterol)

total calorie needs during pregnancy

• an additional 340 kcalories per day during the second semester
• an additional 450 kcalories during the third trimester
• 15-20% more food energy than before pregnancy

(nutrient-dense foods should be chosen to supply the extra kcalories: foods such as whole-grain breads and cereals, legumes, dark green vegetables, citrus fruits, low-fat milk and milk products, and lean meats, fish, poultry, and eggs)

specific micronutrients required for blood production, cell growth, and bone development

• folate
• vitamin B12
• iron (helps to support increased blood volume)
• zinc (required for DNA and RNA synthesis)

(all play a key role in synthesis of DNA and new cells)

energy requirements during lactation

• milk production requires 800 kcal/d
• eat extra 400-500 kcal/d
• remainder from body fat stores
• dieting will reduce milk quantity
• increased need for many micronutrients
• increased need for water, extra 32oz fluids

(nutrient inadequacies reduce the quantity of milk produced, not the quality)

habits incompatible with lactation

• alcohol
• medicinal drugs
• illicit drugs
• smoking
• environmental contaminants
• caffeine

fetal alcohol syndrome

• alcohol crosses placenta freely, deprives fetus of nutrients and O2
• fetal alcohol effects (milder form)
• reduced birth weight
• behavioral effects
• growth restriction (short, underweight)
• hampered learning ability

• fetal alcohol syndrome

• most severe form
• irreversible physical, mental, neurobehavioral abnormalities in the infant

(diagnosed based on poor fetal and infant growth, physical deformities – facial features, brain and CNS impairment)

infant calorie needs vs adult calorie needs

45/lb (100 / kg) vs less than 18/lb (less than 40/kg)

how to assess the growth and nutritional status of infants and children

growth directly reflects nutrient intake and is an important factor in assessing the nutrition status of infants and children

• assessing growth of infants is typically done by plotting their measurements on a percentile graph (they divide measures of a population into 100 equal divisions so that half of the population falls at or above the 50th percentile and half falls above)

using key anthropomorphic measurements

2 dietary practices that have the most significant effect on an infant's nutritional health

• milk an infant receives
• age at which solid (complementary) foods are introduced

milk an infant receives

• unique composition and protective factors found in breast milk promote optimal infant health and development throughout the first year of life
• recommended: exclusive breast feeding for 6 months, breastfeeding with complementary foods for at least 12 months
• 8-12 feedings a day (as soon as infant shows signs of hunger, crying as a late indication of hunger)
• nurses every 2-3 hours, sleeps contentedly between feedings = adequately nourished

age at which solid (complementary) foods are introduced

• introduced at 6 months, breastfeeding with complementary foods for at least 12 months

incidence of childhood obesity

• number of overweight children has increased dramatically over the past four decades
• 32% of US children and adolescents 2-19 years of age are either overweight or obese
• children who are categorized as overweight = 85th percentile and above, obese = 95th percentile and above

environmental factors in the development of obesity in children

• parental obesity
• predicts an early increase in a young child’s BMI
• Less than 10% chance of becoming obese in adulthood with two healthy weight parents
• at least one overweight parent: 80% of being obese adults
• two strongest environmental factors: diet and physical inactivity
• prevalence of childhood obesity throughout the United States more than doubled for young children and more than tripled for children 6 to 11 years of age and adolescents

nutritional needs of adolescents

• energy and nutrient needs are greater during adolescence than at any other time of life, except pregnancy and lactation
• energy needs vary greatly, depending on current rate of growth, gender, body composition, and physical activity
• boys’ energy needs in general may be especially high (grow faster than girls and develop a greater proportion of lean body mass)
• girls start growing earlier than boys and attain shorter heights and lower weights, so their energy needs peak sooner and decline earlier than male peers
• adolescent girls need to pay special attention to being physically active and selecting foods of high nutrient density so as to meet their nutrient needs without exceeding their energy needs
• problems of obesity become more apparent in adolescence, continues into adulthood (more physical and emotional consequences without intervention)
• RDA for most vitamins increases during adolescent years
• need for iron increases during adolescence for both females and males
• need for calcium also reaches its peak
• avoiding too many snacks and sugary drinks

how a teenager’s choice of soda over milk or soy milk may jeopardize their nutritional health

• soft drinks, when chosen as the primary beverage, may affect bone density, partly because they displace milk from the diet
• adolescents who drink soft drinks regularly have a higher energy intake and a lower calcium intake than those who do not

role of childhood obesity in the early development of type 2 diabetes and cardiovascular disease

• insulin resistance as a result of gaining weight → pancreas can’t keep up → blood sugar stays dangerously high → type 2 diabetes
• excess fat causes inflammation (swelling inside blood vessels) → inside of vessels are sticky and damaged, cholesterol sticks to damaged parts → clogged arteries lead to cardiovascular disease

cardiovascular disease (CVD) risk factors

• atherosclerosis begins in childhood
• high blood pressure

type two diabetes

• 85% of children with type 2 diabetes are overweight when diagnosed
• family-history, race (non-Caucasian) increase risk

importance of physical activity in the later years

• compared with those who are inactive, older adults who are active weigh less, have greater strength and flexibility, reduced inflammation, increased bone density, more endurance, better balance, and they live longer
• enjoy better overall health
• additional benefits reaped from various activities as well – aerobic activities improve cardiorespiratory endurance, blood pressure, and blood lipid concentrations
• moderate-endurance activities improve the quality of sleep
• strength training improves posture and mobility
• increases blood flow to the brain, thereby preserving mental ability, alleviating depression, supporting independence, and improving quality of life
• muscle mass and muscle strength tend to decline with aging, making older people vulnerable to falls and immobility (falls are a major cause of fear, injury, disability, and even death among older adults)
• regular physical activity tones, firms, and strengthens muscles, helping to improve balance, restore confidence, reduce the risk of falling, and lessen the risk of injury should a fall occur (also – resistance training helps older adults maintain independence by improving mobility and muscle strength to perform these tasks)

regular physical activity is the most powerful predictor of a person’s mobility in the later years

sarcopenia

• a progressive, age-related syndrome characterized by the involuntary loss of skeletal mass, strength, and function, commonly affecting older adults

nutrients for which there are different requirements in older adults

• fiber
• likelihood of constipation increases with low intakes and changes in the GI tract
• protein
• needs may stay the same or increase slightly
• water
• lack of thirst and decreased total body water make dehydration likely
• energy
• need decreases as muscle mass decreases (sarcopenia)
• vitamin B12
• atrophic gastritis is common
• vitamin D
• increased likelihood of inadequate intake; skin synthesis declines
• calcium
• intakes may be low, osteoporosis is common
• iron
• In women, status improves after menopause; deficiencies are linked to to chronic blood loses and low stomach acid output
• folate
• stomach acid required for absorption, medications may interfere, lowers homocysteine
• zinc
• stomach acid required for absorption, intakes are often inadequate
• vitamin A
• absorption increases with age
• higher circulating levels, decreased need
• vitamin B6
• metabolic use is less efficient

atrophic gastritis

• chronic inflammation of the stomach accompanied by a diminished size and functioning of the mucus membranes and glands
• this condition is also characterized by inadequate hydrochloric acid and intrinsic factor – two substances needed for vitamin B12 absorption

nutrition recommendations for vision changes that occur with aging

• older adults are at higher risk for vision problems as they age (ie. cataracts, macular degeneration)
• cataracts: recommended to increase dietary intake of vitamin C, E, carotenoids (supplements may not help though)
• macular degeneration: preventative factors include antioxidant vitamins + Zn, carotenoids: lutein and zeaxanthin, omega-3 fatty acids from fish

role of nutrition in the prevention and treatment of arthritic conditions

• osteoarthritis / rheumatoid arthritis: alleviating factors include weight loss, low-impact aerobic activity, and resistance strength training (offer improvement in physical performance and pain relief)

common diseases of the aging brain

• alzheimer’s disease
• as brain ages, blood supply decreases, number of neurons diminishes, loss of function depends on neuron location: cortex – hearing and speech, or memory and cognitive function; hindbrain – balance and posture

alzheimer’s disease

a degenerative disease of the brain involving memory loss and major structural changes in neuron networks

role of nutrition in brain function

• nutrients influence development and activities of the brain
• neurons need neurotransmitters
• neurotransmitter synthesis requires micronutrients
• nutrient deficiencies may contribute to loss of memory and cognition experienced by some older adults

food-related factors that can predict malnutrition in older adults (DETERMINE)

Disease

• do you have an illness or condition that changes the types or amounts of foods you eat?

Eating poorly

• do you eat fewer than two meals a day? do you eat fruits, vegetables, and milk products daily?

Tooth loss or mouth pain

• is it difficult or painful to eat?

Economic hardship

• do you have enough money to buy the food you need?

Reduced social contact

• do you eat alone most of the time?

Multiple medications

• do you take three or more different prescribed or over-the-counter medications daily?

Involuntary weight loss or gain

• have you lost or gained 10 pounds or more in the last 6 months?

Needs assistance

• are you physically able to shop, cook, and feed yourself?

Elderly person

• are you older than 80?

commonly used drugs that adversely react with nutrients

• antacids
• anticoagulants
• aspirin
• cathartics
• cholestyramine
• cimetidine
• colchicine
• corticosteroids
• furosemide
• hydrochlorothiazide
• MAO inhibitors
• tricyclic antidepressants

antacids

• Use: Reduce stomach acidity
• Nutrients Affected: Calcium, vitamin B-12, and iron
• Potential Mechanism: Decreased absorption due to altered gastrointestinal pH

anticoagulants

• Use: Prevent blood clots
• Nutrients Affected: Vitamin K
• Potential Mechanism: Interference with utilization

aspirin

• Use: Is an anti-inflammatory; reduces pain
• Nutrients Affected: Iron
• Potential Mechanism: Anemia from blood loss

cathartics

• Use: Induce bowel movement
• Nutrients Affected: Calcium and potassium
• Potential Mechanism: Poor absorption

cholestyramine

• Use: Reduces blood cholesterol
• Nutrients Affected: Vitamins A, D, E, and K
• Potential Mechanism: Poor absorption

cimetidine

• Use: Treats ulcers
• Nutrients Affected: Vitamin B-12
• Potential Mechanism: Poor absorption

colchicine

• Use: Treats gout
• Nutrients Affected: Vitamin B-12, carotenoids, and magnesium
• Potential Mechanism: Decreased absorption due to damaged intestinal mucosa

corticosteroids

• Use: Are an anti-inflammatory
• Nutrients Affected: Zinc and calcium
• Potential Mechanism: Poor absorption of zinc and poor utilization of calcium

furosemide

• Use: Decreases blood pressure; is a potassium-wasting diuretic
• Nutrients Affected: Potassium and sodium
• Potential Mechanism: Increased loss

hydrochlorothiazide

• Use: Decreases blood pressure; is a diuretic
• Nutrients Affected: Potassium and magnesium
• Potential Mechanism: Increased loss and decreased absorption

MAO inhibitors

• Use: Are an antidepressant
• Nutrients Affected: Tyramine (in cheese, wine, and other aged foods)
• Potential Mechanism: High blood pressure caused by limited tyramine metabolism

tricyclic antidepressants

• Use: Are an antidepressant
• Nutrients Affected: —
• Potential Mechanism: Weight gain from appetite stimulation

modifiable lifestyle factors that promote health and disease

• physical inactivity
• stress
• smoking
• drug / alcohol abuse

diet, intake of:

• calories
• fat
• fiber
• sugar
• salt
• vitamins, minerals

nonmodifiable lifestyle factors that promote health and disease

• age
• sex (hormones)
• family history / genetics

interrelationships among chronic diseases

obesity (especially abdominal obesity)

leads to

• some cancers
• diabetes
• atherosclerosis
• hypertension

diabetes leads to

• atherosclerosis (abnormal blood lipids)
• hypertension (high blood pressure)

atherosclerosis leads to

• stroke and heart attack
• hypertension

hypertension leads to

• atherosclerosis
• stroke and heart attack

development of CVD

• Fatty streaks → harden into plaques (lipids, cholesterol, calcium, fibrous tissue).
• Plaques stiffen/narrow arteries.
• Triggered by: high LDL, hypertension, smoking, obesity, etc.
• Damage → inflammation → macrophages engulf oxidized LDL → become plaque cells.
• Plaques can rupture → blood clots → restrict blood flow.
• Result: Heart attack (heart) or stroke (brain)

risk factors for CVD

not modifiable

• increasing age
• male gender
• family history of premature heart disease

modifiable

• high blood LDL cholesterol
• low blood HDL cholesterol
• high blood triglycerides (VLDL)
• high blood pressure (hypertension)
• diabetes
• obesity (especially abdominal obesity)
• physical inactivity
• cigarette smoking
• an “atherogenic” diet (high in saturated fats and low in vegetables, fruits, and whole grains)

specific nutrition recommendations for CVD

• choose a dietary pattern that emphasizes vegetables, fruits, and whole grains; includes low-fat dairy products, poultry, fish, legumes, nontropical vegetable oils, and nuts; and limits intake of sweets, sugar-sweetened beverages and red meats
• limit saturated fat to less than 10% of total kcalories (for those who have been advised to lower LDL cholesterol or those who have diabetes, limit saturated fat to 5 - 6% of total kcalories)
• limit sodium intake to 1500 mg per day
• practice moderation with alcohol if consumed
• avoid exposure to any form of tobacco or tobacco smoke

development of hypertension

• underlying causes of most hypertension cases are not fully understood
• more is known about the physiological factors that affect blood pressure, which arise from contractions in the heart muscle that pump blood away from the heart and the resistance blood encounters in the arterioles (influenced by the nervous system and hormone signals)
• kidneys play a role in regulation of blood pressure by controlling the secretion of hormones involved in vasoconstriction and retention of sodium and water

risk factors for hypertension

• aging
• genetics
• obesity
• salt intake
• alcohol

specific nutrition recommendations for hypertension

• maintain a healthy body weight
• adopt a diet that includes abundant fruits, vegetables, and whole grains; moderate low-fat milk products, poultry, fish, legumes, and nontropical vegetable oils, and nuts; and minimal sweets, sugar-sweetened beverages, and red meats
• reducing dietary sodium intake to less than 2300 mg sodium per day, further reduce intake to 1500 mg among people who have prehypertension or hypertension
• perform aerobic physical activity for at least 40 minutes per day, most days of the week
• moderate alcohol consumption: men, limit to two drinks per day; women and lighter-men, limit to one drink per day

DASH: Dietary Approaches to Stop Hypertension

• eating pattern rich in fruits, vegetables, low-fat milk products, whole grains, and nuts, and low in total fat and saturated fat (proven to significantly lower blood pressure)

development of diabetes

• Cause: insufficient or ineffective insulin → hyperglycemia (damages vessels, nerves, tissues).
• Diagnosed: fasting plasma glucose or A1C.

Type 1 (5–10%):

• Autoimmune destruction of insulin-producing beta cells → no insulin → needs insulin injections.

Type 2 (90–95%):

• Insulin resistance (cells less sensitive to insulin) → insulin can't compensate.

Both types:
Glucose can't enter cells → accumulates in blood → complications (large/small vessel disease, nerve damage).

risk factors for diabetes

type 2

• obesity
• poor dietary habits
• smoking
• excessive alcohol consumption
• aging
• physical inactivity

specific nutrition recommendations for diabetes

• delivering same amount of carbohydrates each day, spaced evenly throughout the day
• using glycemic index to provide some additional benefit for achieving glucose control as compared with that obtained by considering only the amount of carbohydrate consumed
• reducing saturated fat intake to less than 10% of kilocalories and limiting trans fats as much as possible
• consume more foods rich in omega-3 fatty acids
• individualizing protein intake to control blood glucose or to improve CVD risk factors
• drinking alcohol in moderation

type one diabetes recommendations

• maintaining optimal nutrition status, controlling blood glucose, achieving a desirable blood lipid profile, controlling blood pressure, and preventing and treating the complications of diabetes

type two diabetes recommendations

• (moderate) weight loss
• good diet, regular routine of moderate physical activity

development of cancer

• begins as a single cell that loses control of its normal growth and replication processes
• arises from mutations in the genes that control cell division in a single cell
• cell loses built-in capacity for halting cell growth
• abnormal mass of cells (tumor) grows; network of blood vessels develops to supply the tumor with the nutrients it needs to support its growth
• can disrupt normal functioning of tissue around it, some tumor cells metastasize to other regions of body

risk factors for cancer

environmental factors

• exposure to radiation and sun
• water and air pollution
• smoking
• lack of physical activity
• obesity
• increased risk of breast cancer after menopause

dietary factors (linked to as many as ⅓ of all cancer cases) & specific nutrition recommendations

specific nutrition recommendations for cancer

• Maintain healthy weight: Balance calories, stay active, limit sugary drinks & fast foods
• Be physically active: ≥150 min moderate or 75 min vigorous activity/week; reduce sedentary time
• Eat mostly plant foods: Fruits, vegetables, whole grains; limit red & refined foods
• Limit alcohol: ≤2 drinks/day (men), ≤1 drink/day (women)
• Reduce processed/salty foods: Avoid processed meats; keep salt <6 g/day
• Skip supplements for prevention: Get nutrients from food, not pills

how nutrition impacts the immune system

• malnutrition compromises immunity
• impaired immunity increases susceptibility to infectious disease
• infectious diseases typically:
• raise nutrient needs
• lower food intake
• nutrition status suffers further
• synergistic downward spiral

potential impact of adhering to the Dietary Guidelines for Americans and MyPlate on chronic disease risk

• recommendations to prevent chronic diseases take a population approach and urge all people to make dietary changes believed to forestall or prevent diseases
• for many people, diet influences the time of onset and course of some chronic diseases

two ways in which foodborne microorganisms can cause illness in the body

• foodborne infections
• foodborne intoxications

foodborne infections

caused by eating foods contaminated by infectious microbes

• pathogens commonly enter the GI tract in contaminated foods such as undercooked poultry and unpasteurized milk

examples of foodborne infections

salmonella, listeria

foodborne intoxications

caused by eating foods that contain natural toxins or, more likely, microbes that produce toxins

examples of foodborne intoxications

staphylococcus aureus, clostridium botulinum

methods to prevent foodborne illness during food production and service

farm: workers must use safe methods of growing, harvesting, sorting, packing, and storing food to minimize contamination hazards

processing: processors must follow FDA guidelines concerning contamination, cleanliness, and education and training of workers and must monitor for safety at critical control points

transportation: containers and vehicles transporting food must be clean; cold food must be kept cold at all times

retail: employees in grocery stores and restaurants must follow the FDA’s Food Code on how to prevent foodborne illnesses; establishments must pass local health inspections and train staff in sanitation

table: consumers must learn and use sound principles of food safety as taught in this chapter; be mindful that foodborne illness is a real possibility, and take steps to prevent it

actions that should be taken by consumers to help prevent food borne illnesses when dining out

• wash hands with hot, soapy water before meals
• expect clean tabletops, dinnerware, utensils, and food preparation areas
• expect cooked foods to be served piping hot and salads to be fresh and cold
• refrigerate take-home items within 2 hours and use leftovers within 3 to 4 days

HACCP (Hazard Analysis Critical Control Point)

a systematic plan to identify and correct potential microbial hazards in the manufacturing, distribution, and commercial use of food products

pasteurization

heat processing of food that inactivates some, but not all, microorganisms in the food; not a sterilization process; bacteria that cause spoilage are still present

food irradiation

sterilizing a food by exposure to energy waves, similar to ultraviolet light and microwaves; sometimes called ionizing radiation

4 components of food safety in the kitchen (Fight Bac!)

CLEAN: wash hands and surfaces often

SEPARATE: don’t cross contaminate

COOK: cook to proper temperatures

CHILL: refrigerate promptly

environmental contaminants in the food supply

• methylmercury
• lead
• Dioxin
• arsenic
• PCBs (polychlorinated biphenyls)
• pesticides
• phthalates (chemicals used to make plastics more flexible, exposure when eating/drinking foods in containers with them)

natural toxicants found in foods

• poisonous mushrooms
• goitrogens (found in cabbage, broccoli, etc. – can enlarge thyroid gland)
• cyanogens (lima beans and fruit seeds ie. apricot pits; inactive compounds that produce cyanide upon activation by a specific plant enzyme)
• solanine (hazardous when consumed in large quantities; narcotic-like)

advantages associated with organic foods

• reduced pesticide exposure
• higher antioxidant levels in some cases
• better environmental sustainability due to reduced chemical use

disadvantages associated with organic foods

• using unprocessed organic fertilizer may transmit bacteria to humans
• nutritionally equal to conventional foods
• BGH, hormones, antibiotics

common additives in the food supply

antimicrobial agents

• salt, sugar
• nitrites, nitrates

antioxidants

• Vitamin C
• Vitamin E
• sulfites
• BHA, BHT

colors

• artificial (blue #1, #2), green (#3), red (#40, #3), yellow (#5, #6)
• natural pigments (carotenoids, beets, grape skins)

natural flavors, artificial flavors, and flavor enhancers

• largest single group of food additives
• salt, sugar, spices, artificial sweeteners, MSG

texture and stability

• emulsifiers, gums

risks of genetically engineered foods

• disruption of natural ecosystems
• introduction of diseases
• introduction of allergens and toxins
• creation of bio weapons
• ethical dilemmas

antimicrobial agents

benefits: prevent food spoilage from microorganisms

drawbacks: antimicrobial resistance

antioxidants

benefits: prevent oxidative changes in color, flavor, or texture and delay rancidity and other damage to foods caused by oxygen

drawbacks: overconsumption can make them act as pro-oxidants, damaging cells, interfering with beneficial exercise adaptations, and inhibiting mineral absorption

colors

benefits: enhance appearance

drawbacks: potential cancer risks

flavors

benefits: enhance taste

drawbacks: encourage overeating and obesity and have other long-term health effects

emulsifiers and gums

benefits: thicken, stabilize, or otherwise improve consistency and texture

drawbacks: potential contribution to obesity, CVD, disruption of gut microbiota, etc.

nutrients (vitamins and minerals)

benefits: improve the nutritive value by replacing vitamins and minerals lost in processing (enrichment) or adding vitamins or minerals that may be lacking in the diet (fortification)

drawbacks: nutrient toxicity from overconsumption

benefits of genetically engineered foods

• increased resistance to pests and diseases
• tolerance of adverse conditions
• plants, crops able to grow in poor or polluted soil
• drought resistance, irrigated with seawater
• tolerance of herbicides
• functional characteristics
• lower amounts of allergens
• delayed ripening, increased shelf life
• increased starch content
• enhanced nutritional qualities
• contain a desired nutrient
• increased amount of nutrient already present