Nutrition 206 Final

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291 terms · The terms are not in order as per the syllabus (I dropped my notes at the bus stop). If you question some of the values let me know, I had to use other sources to fill in some of the blanks.

What is Nutrition?

-study of food, how it nourishes our body, how it influences our health

5 Aspects of Nutrition

1. Nutrients
2. Digestion
3. Absorption
4. Metabolism
5. Elimination
*all are affected by stress*

What are Nutrients?

def: chemicals in foods that are critical to human growth & function

6 Classes of Nutrients

1. Carbohydrates
2. Fats & Oils
3. Proteins
4. Vitamins/ Minerals
5. Water
6. Electrolytes

Energy is Measured in ...?

Kilocalories (kcal or C):
-the amt of energy required to raise the temp. of a litre (kg) of water one degree centigrade at sea level

1 kcal = 1000 calories
3500 cal = 1 lb

5 Dimensions of Health

1. Physical: following food guide
2. Mental: consumer decisions
3. Emotional: flexible w eating habits
4. Social: tests resolve in following food guide
5. Spiritual: caring for one's body

Integrating Nutrition Assessment (ABCD)

Anthropometric: BMI, head circumference (objective)
Biochemical: Bloodwork
Clinical: physical observations of S&S
Dietary Data: food consumption recall (subjective)

Nutritional Assessment

Undernutrition
Overnutrition
Malnutrition

Undernutrition

the consumption of not enough energy or nutrients based on DRI (dietary reference intakes) values
e.g. scurvy (Vit. C), rickets (Vit. D), anemia (Iron)

Overnutrition

the consumption of too many nutrients and too much energy compared with DRI levels

Malnutrition

imbalanced nutrient and/or energy intake
*at-risk: hospital patients, older adults, & chronic excessive alcohol/drug users

Medical conditions controlled by nutrition therapy:

-diabetes
-heart disease
-hypertension
-renal

Physical complaints that interfere with intake:

-difficulty chewing & swallowing
-anorexia "not eating"
-heartburn
-nausea
-vomiting
-pain

Increased needs:

-pregnancy
-fever
-sepsis (blood infection)
-thermal injuries (burn)
-skin breakdown
-cancer
-AIDS
-surgery
-trauma (MVA)

Losing nutrients:

-malabsorption
-diarrhea
-some renal disease

S&S of Malnutrition

-hair is dull, brittle, dry, falls out easily
-swollen glands of neck & cheeks
-dry, rough, spotty skin
-poor or delayed wound healing or sores
-thin appearance with lack of subcutaneous fat
-muscle wasting
-edema of lower extremities
-weakened hand grasp
-depressed mood
-abnormal heart rate/rhythm & BP
-enlarged liver & spleen
-loss of balance & coordination

DIET is a 4-letter word, instead use:

-eating patterns
-food intake
-eating style
-the food you eat

Factors that interfere with nutrition therapy

-client's prognosis
-outside support systems
-level of intelligence & motivation
-willingness to comply
-emotional health
-financial status
-religious or ethnic background

Accessory Organs of the Digestive System

-Pancreas
-Liver
-Gallbladder

Digestion

-involves macronutrients CHO, PRO, FAT
-Mechanical: mastication of bolus into chyme
-Chemical: digestive enzymes

Macronutrients involved in digestion:

-carbohydrate (CHO)--> glucose
-protein (PRO)--> amino acids
-fat (FAT)--> fatty acids

Absorption

-process which food molecules are taken up by the intestinal villi & distributed to body cells via the bloodstream
-minerals absorbed in duodenum
-glucose & water soluble vit. absorbed in jejunum
-protein, fats & fat-soluble vit. absorbed in ileum
-water absorbed in large intestine

Metabolism

-chemical rxns in body cells that convert fuel from food into energy
-catabolism: "cut" or "break-down"
glycogen→glucose (liver)
-anabolism: "add" or "build-up"
amino acids→PRO (DNA directs PRO building)
glucose(CHO)→glycogen
excess kilocalories→Lipogenesis

Elimination

-food molecules that can't be absorbed or digested are eliminated from the body

Mouth

-breaks down food: mastication (mechanical digestion)
-mixes food with saliva (chemical digestion) to form bolus, lubricate esophagus
-secretes salivary amylase to help digest CHO

Esophagus

-transports food to stomach
-passes to stomach via Esophageal sphincter

Stomach

-acts as food resevoir
-mixes food with gastric juices: HCL, Protease (pepsin), mucus, intrinsic factor
-breaks down food into chyme
-absorbs water, alcohol, & some drugs
-passes to duodenum of sml intestine via Pyloric sphincter

Small Intestine

-duodenum, jejunum, ileum
-stimulates secretion of pancreatic juices
-major site of digestive absorption (primarily in duodenum)
-nutrients & fluids pass through intestinal cells into the blood system --> transported to liver
-fats & fat-soluble vit. & some fluid enter lymphatic system from intestinal cells (via lacteals)

Pancreas (accessory)

endocrine: produces & secretes insulin and glucagon
exocrine: produces & secretes digestive enzymes: protease (PRO->amino acids), lipase (FAT->fatty acids), amylase (CHO->simple sugars), bicarbonate (neutralizes acidic chyme)

Gallbladder (accessory)

-concentrates & stores bile
-releases bile into the duodenum to emulsify fat

Liver (accessory)

-produces bile (stored in the gallbladder) to emulsify fats, & help regulate cholesterol
-metabolizes CHO, PRO, FAT
-stores nutrients (iron, vit. A, D, E, K & B12, glycogen)
-detoxifies drugs & waste products in the blood

Large Instestine

-chyme passes into lrg intestine via ileocecal sphincter
-food that is undigested, or unabsorbed is fermented by intestinal bacteria
-held for 12-24 hrs
-B complex, K & water are absorbed
-end result is eliminated via anus

Vitamins

-required for proper metabolism
-do not directly provide energy
-necessary for obtaining energy from macronutrients
-often fxn as coenzymes
-some are antioxidants

Enzyme

a protein that accelerates the rate of a chemical rxn
*required for all metabolic fxns

Coenzyme

a molecule that combines with an enzyme to facilitate enzyme fxn
*some metabolic rxns require coenzymes

Antioxidant

substances that donate electrons to free radical to prevent oxidation
*Vit. C, E, and beta-carotene are major antioxidants

Two categories of solubility

-Water-soluble are dissolved in water
e.g. B complex, choline & vit. C
-Fat-soluble are dissolved in fatty tissue (stored in body-> risk for toxicity)
e.g. Vit. A, D, E, K

B-Complex Vitamins

-especially important for energy metabolism
e.g.
thiamin (TPP) folate (THF)
riboflavin (FAD,FMN) vitamin B₁₂ (B₁₂)
niacin (NAD) biotin (biotin)
vitamin B₆ (PLP) pantothenic acid (CoA)

Wernicke-Korsakoff Syndrome:
Thiamine B1

-neuropsychiatric effect of chronic excessive alcohol intake
*S&S: memory loss, extreme mental confusion, ataxia (can't walk straight), DT's (delirium tremens - withdrawal symptoms)
those at risk: severe GI disease, HIV, improper parenteral glucose solutions

Thiamine

-needs increase during illness, stress & surgery
-"morale vitamin" due to beneficial effects on nervous system & mental attitude
-NSAIDS ie antacid, tobacco, caffeine, sugar & alcohol deplete thiamine

Vitamin B2-Riboflavin

-most common vitamin deficiency
-S&S: sore throat, cheilosis, stomatitis, glossitis, & dermatitis
-promotes healthy skin, nails & hair
-helps alleviate migrain headaches
-light, water, sulfa drugs & alcohol are destructive
-need more B2 if you are on the pill, pregnant, or lactating

Vitamin B6-Pyridoxine

-essential for proper nervous system fxn (involved in formation of neurotransmitters)
-coenzyme for fatty acid & CHO metabolism
-sources: whole grains & cereals, legumes, and chicken, fish, pork, and eggs
-supplement toxicity can result in nerve damage, skin lesions
-depleted by birth control

Vitamin B6-Pyridoxine benefits

-alleviates nausea
-reduce night muscle spasms (Mg helps this as well)
-heavy protein consumers need more B6
-lowers risk of heart disease when used in combo with folic acid to break down amino acid homocysteine

Folate (folic acid)

-critical for cell division of early embryos
role in proper formation of fetal neural tubes
-coenzyme involved in DNA synthesis, amino acid metabolism
-sources: leafy green vegetables, lentils, fortified grain products
-women of childbearing age should increase folate intake to 400 mcg
-excess folate can mask B₁₂ deficiency in older adults

Vitamin B₁₂

-required for metabolism of fatty acids and amino acids
-develops and maintains myelin sheaths around nerve fibres (reverse dementia?)
-intrinsic factor
-sources:meat, fish, poultry, eggs, dairy

Vitamin B₁₂ Deficiencies

Pernicious anemia:
-breakdown of myelin sheath synthesis
-damage to spinal cord affects brain, optic & peripheral nerves
Also:
-reduced intrinsic factor production
-neuropsychiatric symptoms (delusions, hallucinations, dementia)

Vitamin C functions

-fxn: as antioxidant and coenzyme
-holds structures together, provides "cement", ie collagen formation for bone matrix, teeth, cartilage, skin & connective tissue
-required for wound healing w new tissue formation
-sources: fruits (citrus, strawberries, tomatoes), veggies (red & green pepper, potatoes, broccoli, leafy greens)
-destroyed by light, air, heat

Vitamin C Deficiencies

AKA Hypocalcemia
Scurvy:
-inflammation & eventual hemorrhaging of connective tissue as vascular system weakens

Vitamin C Toxicity

AKA Hypercalcemia
-High dose of vitamin C negates local anesthesia
-body develops a mechanism that destroys excessive vit. C circulating in the blood ∴ no toxicity from foods high in vit. C

Vitamin C: the good

-accelerates healing
-aids in prevention of bacterial & viral infections
-reduces histamine in the blood by 40%
-Aspirin triples the excretion rate

Fat soluble Vitamins

Vitamins A, D, E, K
-sources: fat & oil portion of foods
-when consumed in excess stored primarily in liver & adipose tissue
-toxic in high dosages (ie supplements)
-does not have to be consumed daily as body retrieves it from storage when needed

Vitamin A

-maintains skin and mucous membranes
-fxn: vision, bone growth, immune system, & normal reproduction
-sources: natural preformed in whole milk, butter, liver, egg yolks, fatty fish, carotenoids in deep green, yellow, & orange fruits and veggies
-BEST sources: broccoli, cantaloupe, sweet potatoes, carrots, tomatoes, and spinach

Vitamin A: the good

-Provitamin A (Beta-carotene) is preferred b/c it does not have the same toxicity potential as vit. A
-Topical Retin A is used for acne & wrinkles
NEG: Oral forms (accutane) prescribed for skin problems is potent, and can cause birth defects, liver damage, depression, suicide & Crohn's

Vitamin D

-steroid synthesizing is stimulated by the sun under OPTIMAL cond. & liver and kidney fxn is normal
-∴acts like a hormone b/c it is synthesized in one place (skin) & stimulates functional activity elsewhere
-fxn: intestinal absorption of Calcium & Phosphorus, affects bone mineralization, affects mineral homeostasis by helping to regulate blood calcium levels
-souces: butter, egg yolks, fatty fish & liver

Vitamin D deficiency

-Rickets: a childhood disorder leading to insufficient mineralization of bone & tooth matrix (eg. malformed skeletons, bowed legs, oddly angled rib bones, and abnormal tooth formation.
-Osteomalacia: an adult disorder characterized by soft, demineralized bones (risk for fractures). Symptoms include weakness, rheumatic-like pain, awkward gait.
-Osteoporosis: multifactorial disorder in which bone density reduced & remaining bones brittle, breaking easily eg. ↑ risk of CAD, rheumatoid arthritis, cancers, type 1 diabetes, MS

Vitamin D deficiency: concerns

deficiency concern when lack of exposure to sunlight occurs as result of:
-environmental limitations
-cultural clothing customs concealing body
-inability of older adults or people with disabilities to get outdoors or to store, resulting in malnourishment
-sunscreen (SPF8 blocks by 95%)
→ fortified dietary sources, or supplements appropriate

Vitamin E

-acts as antioxidant in conjunction with selenium & ascorbic acid (vit. C)
-protects polyunsaturated fatty acids & vitamin A in cells from oxidative damage by being oxidized itself (particularly the integrity of lung & blood)
-sources: vegetable oils, margarine, whole grains, seeds, nuts, wheat germ, & greeny leaf (processing ↓ final vit. E content)

Vitamin E: the good

-prevents & dissolves blood clots
-accelerates healing of burns
-prevents thick scar formation externally (applied topically) & internally
-↑ doses can interfere w vit. K (promotes blood clotting)
-body absorbs natural sources 2x as well as synthetic ones

Vitamin K

-cofactor in synthesis of blood-clotting factors (incl. prothrombin)
-role in protein formation in bone, kidney & plasma
-sources: dietary sources & synthesized by microflora in the jejunum & ileum of digestive tract
dark green leafty vegetables, dairy products, cereals, meats & fruits

Vitamin K: deficiency

-inhibits blood coagulation
-may be observed in clinical settings related to malabsorption disorders or medication interactions
--effects of long-term intensive antibiotic therapy (kills microflora)
--barriers to fat absorption
--inability to produce vit. K by premature infants & newborns (no natural bacteria yet)

Vitamin K: toxicity

-medications affected ie anticoagulant medications like warfarin & other blood thinning drugs
-excess amts may ↓ clotting time, ↑ risk for stroke
-supplement only under advice from dietician or health care provider

Vitamin K: the good

3 kinds K1, K2, K3
-K2 can be formed by natural probiotic bacteria in the intestines
-K2 controls removal oc calcium from arteries & deposition of calcium into bones, thus providing benefits for bone health and CV health

Water

500 mL/day - to release toxins or 30 mL/hr
-kidneys regulate amt excreted
-relies on combo of brain, kidney, pituitary gland & adrenal gland

Sources of Water

-food
-beverages (coffee, tea & alcohol are diuretics - pee more; soda adds fluid to body, but contains solutes)
-metabolism (produced through breakdown of fat, carbs, protein - contributes to 10-14% RDI)

Lack of water→Thirst sensation

-↑ sodium
-Osmotic thirst
-↓in blood volume (hypovolemic thirst AKA pathological thirst)

Water losses

Sensible:
-excreted by kidneys as urine
-excreted in feces (sml amt)
Insensible:
-sweating (3-4 L/day)
-breathing (1-2 L/day)

Fluid Volume Deficit (FVD)

can occur from:
-diarrhea
-vomiting
-high fever
-sweating
-diuretics
-polyuria (↑ urination)

FVD characteristics

-infrequent urination
-↓ skin elasticity (ie tenting, or turgor)
-dry mucous membranes
-dry mouth
-unusual drowsiness
-lightheadedness or disorientation
-extreme thirst
-nausea
-slow or rapid breathing
-sudden weight loss

Dehydration

Early signs:
-headache, fatigue, anorexia, flushed skin, lightheadedness, dry mouth & eyes, dark urine
Increased risk:
- infants (do not concentrate urine as readily as adults or express thirst, ↑ proportion of body weight to water)
-elderly (↓ total amt of body water, thirst sensation ↓)

Fluid Volume Excess (FVE)

-↑ fluid retention & edema (ie compromised regulatory mechanism)
-water intoxication (dilution of electrolytes causing muscle cramps, ↓ BP, & weakness)
-occurs when intake ≠ output

Electrolytes

minerals that dissolve in water to rom electrically charged particles (ions) which can carry an electrical charge
Intracellular (+) charge: K (potassium) & Na (sodium)
Interstitial (-) charge: Ph (phosphorus) & Cl (Chloride)
Extracellular (ECF): plasma & watery components of body organs & substances

Sodium: function

-BP & volume maintained by sodium as major cation in ECF
-transmission of nerve impulses
-role in regulation of body fluid levels in & out of cells

Sodium

-RDI: 2300-2400 mg/day (≈6g or 1 tsp)
souces:
-table salt
-foods in which it naturally occurs
-widely used in processed foods

Sodium: deficiency

-depletion can develop from dehydration or excessive diarrhea or excessive sweating (hyponatremia)
symptoms: headache, muscle cramps, weakness, ↓ ability to concentrate, ↓ memory, anorexia

Potassium: function

-primary intercellular cation
-maintains fluid levels inside the cells
-crucial for nerve & muscle fxn ie heart
-RDI: 4600mg
-sources:
whole unprocessed foods, white potatoes w skin, sweet potatoes, tomatoes, bananas, oranges, other fruits & veggies, dairy products, & legumes

Potassium: deficiency

-aka hypokalemia
-dehydration (ie vomiting, diarrhea, diuretics, laxative misuse)
- long-term diuretic use
symptoms:
muscle weakness, confusion, anorexia, cardia dysrhythmias (severe cases)

Potassium: toxicity

-occurs only w supplements (hyperkalemia)
symptoms:
muscle weakness, vomiting, cardiac arrest (severe cases)

Minerals

-vitamins cannot fxn & cannot be assimilated w/out the aid of minerals
-the body cannot manufacture a single mineral
→Macro (major): Ca, Cl, K, Ph
→Micro (minor): Fe, I, Zn, Se, Fl, Cr, Mo, CuMn
*all are critical to life!*

Mineral: sources

plant foods: fruits, veggies, legumes & whole grains
animal foods: beef, chicken, eggs, fish, milk products
*found in all 4 food groups*
-indestructible inorganic substances: stable when foods containing them are cooked

Mineral: functions

-structure
-fluid balance
-acid-base balance
-nerve cell transmission & muscle contraction
-vitamin, enzyme & hormonal activity

Calcium

-most abundant mineral 99% in bones
sources:
-dairy products, green leafy veggies, small fish, legumes, processed tofu
deficiency:
-osteoporosis

Phosphorus

-widely available in processed foods & pop
-excessive consumption ↑ calcium excretion
ie renal disease

Magnesium

-often overlooked & is deficient in many diets
-↑ nerve fxn
-helps w sleep & stress
-assists 100s of enzymes
sources:
-unprocessed whole grains, legumes, broccoli, leafy green veggies, and others
deficiency:
-2° rather than 1° ie. ↑vomiting & diarrhea, or GI tract disorder affect absorption or kidney disease - retention
-malnutrition & alcoholism ↓Mg levels

Fluoride

-↑resistance to tooth decay
sources:
-fortified water, tea, seafood, seaweed
Toxicity:
-fluorosis (mottling or brown spotting of the tooth enamel, severe cases may see pitting)

Iodine

-part of hormone thyroxin (produced by thyroid gland)
sources:
-seafood, dairy products, eggs
deficiency:
-reduces amt of thyroxine produced (ie. goiter)
-symptoms incl. sluggishness & weight gain
-during pregnancy causes cretinism = permanent mental & physical retardation

Iron

-most common mineral DEFICIENCY
-↑risk for infants, young children, preteen girls, premenopause, & pregnant women
sources:
-meat, poultry, fish, clams, soybeans, enriched cereals & breads, lentils
Toxicity:
-overdose most common cause of poisoning deaths in children
-symptoms: nausea, vomiting, diarrhea, dizziness, confusion
-if tx delayed = severe damage to heart, CNS, liver, kidneys

Energy Use: 3 general purposes (+ 1 non-general purpose)

1. basal metabolism
2. physical activity
3. thermic affect of food
+1. non-exercise activity thermogenesis

Basal Metabolism

-min. energy expended in a fasting state (12 hrs) to keep a resting, awake body alive in a warm, quiet environment
-requires 60-70% of energy
-process involved in maintaining HR, Resp, temp
-amt of energy needed to maintain life when subject is at rest
BMR = healthy weight (lbs) X 10 (women) or 11 (men)

Other influences on Basal Metabolism

-↑ temp - ↑ BM
-↑ age - ↓ BM
-↓ eating - ↓ BM
-pregnancy - ↑ BM
-Caffeine & Tobacco - ↑ BM
-Thyroid hormones - ↑ or ↓ BM
-Nervous System activity - ↑ BM

Energy intake

-calories from:
carbs - 4 cal/g
protein - 4 cal/g
fat - 9 cal/g
alcohol - 7 cal/g

Calories in vs. Calories out

energy balance is the relationship btwn the amt of calories consumed & the amt of calories expended
(+) calorie in > calorie out
(-) calorie in < calorie out

When do you need (+) Energy Balance?

-growing kids
-breast feeding
-pregnancy

Normal Weight

- normal weight is statistically correlated to good health
3 criteria for assessing overweight & obesity:
-Body Mass Index (BMI)
-Waist Circumference
-Existing health problems

BMI= wt (kg)/ht (m²)
*does not consider body composition*

Ideal BMI ranges

Ideal Body Weight (IBW): 18.5-24.9
overweight: 25-29.9
Class I Obesity: ≥ 30
Class II Obesity: ≥ 35
Class III Obesity: ≥ 40
underweight: < 18.5
anorexia nervosa: < 16

Causes of Obesity

-energy intake > expenditure
-genetics
-hormones (menopause, thyroidism)
-emotional/ psychological factors (stress)
-environmental factors (how were they raised)

Macronutrients

CHO (carbohydrate) = 4 kcal/g
PRO (protein) = 4 kcal/g
Fats = 9 kcal/g
*Alcohol = 7 kcal/g (not considered a macronutrient)
-are organic & digestible
-they can break down into component molecules

Component Molecules

Carbon
Hydrogen
Oxygen
*Nitrogen (only in PRO)

Carbohydrates (CHO)

-majority of calories in almost all diets
-source of energy (4 kcal/g)
-required for normal body fxn e.g. 100 mg/day glucose: brain fxn
2 Types:
1. Simple
2. Complex

Simple Carbohydrates (2)

1. Monosaccharides (travel to the liver)
-Glucose = Dextrose (released for cell use)
-Fructose (converted to glucose)
-Galactose (converted to glucose)
2. Disaccharides
-Maltose (Maltase→Glucose+Glucose)
-Sucrose (Sucrase→Glucose+Fructose)
-Lactose (Lactase→Glucose+Galactose)

Complex Carbohydrates

Polysaccharides (not sweet)
-Starch (1-4 hrs to digest 95%)
-Glycogen (stored in liver, & muscles)
-Fibre (not digested, forments in lrg intestine)
--soluble: delays absorption of glucose, delays/blocks absorption of cholesterol
--insoluble: ↑ fecal wt, ↑ transit time in intestine, relieves constipation
---may ↓ risk of colon cancer, diverticulosis, & type II diabetes

Glucose Homeostasis

serum glucose kept at a constant level by 2 hormones (both are synthesized, stored & secreted by the pancreas):
-glucagon
--stimulated by ↓glucose levels
--stimulates liver to convert glycogen→glucose
--assists in breaking down PRO→AAs
--stimulates liver into producing glucose from AAs
-insulin
--stimulated by ↑glucose levels
--required for glucose transport
--stimulates liver & muscle to take up glucose

Glycemic Index

a measure of how the ingestion of a particular food affects blood glucose & insulin levels
-does not take into account how much sugar a particular food contains, only how quickly the sugar is absorbed

Glycemic Load

-the body's glycemic response depends on the type of food eaten & the amt of CHO calories consumed
-the ↑ concentrated a CHO is, the more sugar it dumps into the blood
e.g. sugar from carrots is absorbed quickly in the bloodstream (↑ Glycemic Index), but not a lot of sugar to begin with (↓ Glycemic Load)

Carbohydrates to eat

One serving = 15g of CHO
-5-12 servings: Whole grains & cereals
-1 serving: Legumes (dried peas & beans)
-5-10 servings: Fruits/Vegetables
-Milk (considered a CHO)
-2+ servings of fibre daily
-↑ water intake
CHOOSE more COMPLEX carbs

Risk Factors of ↑ Sugar Consumption

-dental caries
-empty cal - no substance or nutrients
-hyperactivity
-Obesity
-Diabetes

Artificial Sweeteners

intensely sweet synthetic compounds that sweeten foods without providing calories (nonnutritive)
-1.6 to 2.6 cal/g
-Saccharin, Aspartame (Aspartic Acid + phenylalanine), Acesulfame-K, Sucralose
-incompletely absorbed
-do not promote dental caries
-can have laxative effect (e.g. bloating, gas, & diarrhea)

Carbohydrate Metabolism Disorders (3)

1. Lactose intolerance
-insufficient lactase (not an allergy)
-ingestion of lactose causes bloating, cramping, gas, diarrhea, nausea
2. Diabetes Type I
-insufficient insulin produced by pancreas
-no known etiology
3. Diabetes Type II
-body becomes less responsive/resistant to insulin
-combination of genetics, obesity, sedentary lifestyle
-can improve with diet restrictions

Lipids (Fats)

an oily organic compound insoluble in water but soluble in organic solvents
-triglycerides (fats, oils), phospholipids (lecithin), steroids (cholesterol)

Lipid Function

-energy 9 cal/g (not preferred energy source)
-support & protection for internal organs
-Temp. regulation (insulation)
-Absorption of Fat-soluble vitamins
-improves food flavour
-tenderizing & moisture (in baked goods)
-provide essential fatty acids (EFAs)

Triglycerides

-95% of fats in foods (fatty acids)
-glycerol combo w 3 of 5 different fatty acids
-major storage form of fat in the body
-transported through bloodstream by VLDL
2 types:
1. Saturated
2. Unsaturated

Saturated Fats

-fatty acid chains are 'saturated' w H+ ions (more stable than unsaturated)
-solid at room temp.
-↑ melting point
-mostly animal origin, a few plant sources (e.g. butter, whole milk, beef, coconut oil, palm kernel oil)
-the more saturated = ↑ risk for ↑ bad cholesterol (LDL) levels in blood

Unsaturated Fats

-soft/liquid at room temp.
-often referred to as monounsaturated (olive oil, peanut oil) or polyunsaturated (corn oil, safflower oil)
-↓ melting point
-susceptible to becoming rancid when exposed to light or O₂ for long periods of time

Hydrogenated Fats

-unsaturated vegetable oils that have been altered to become more saturated (corn, soybean, safflower, canola)
-done to improve stability of of the fat or oil, change its texture, ↑ functionality (i.e. flakier pie crusts, reusable for deep frying)
-any health benefits are eliminated w hydrogenation
-similar to unsaturated but classified as saturated
-trans-fats ↑ LDL (lousy) & ↓ HDL (healthy)

Omega 3 & 6

-EFAs (polyunsaturated) as body cannot produce
-both highly concentrated in the brain & are important for cognitive & behavioural fxn
Omega 6 (linolenic acid): in veggie & nut oils
-do not need to supplement
Omega 3 (α-linolenic acid): leafy green veggies, fish & plants oils
-reduce inflammatory response, ↓ blood clotting & plasma triglycerides (↓ risk of heart attack)
-need to supplement

Phospholipids

-occur naturally in almost all foods (e.g. liver, eggs, wheat germ, peanuts)
-vital fxn:
--emulsifiers to keep fats suspended in blood & body fluids
--component of all cell membranes, provide structure & help transport fat-soluble substances across the membrane, precursors of prostaglandins

Sterols

-group of steroids (cholesterol, sex hormones, cortisol, bile salts, Vit. D)
-in plant & animal foods, & produced by the body
-some steroids are synthesized from cholesterol
-fxn depends on individual steroid

Blood Cholesterol

-found in eggs, dairy, beef, pork
-synthesized by Liver
--diets ↑ in fats - even those ↓ in cholesterol = ↑ serum cholesterol levels for 2 reasons:
1. stimulates reabsorption of cholesterol back into the blood (↓ the amt of cholesterol lost in faces)
2. saturated fats are broken down & the liver cells use some of the products to produce cholesterol

High Cholesterol Risk Factors

-Male > 40 yrs
-Female > 50 yrs
-Post Menopausal
-Have Heart Disease or Diabetes
-↑ BP
-Obese, especially around the middle
-Smoker or Hx of smoking
-Strong family Hx of heart disease/↑ cholesterol

Lowering Cholesterol

-maintain a healthy wt
-eat a healthy, reduced-fat diet
-be physically active on a regular basis (20-30 min every day)
-don't smoke
-have your blood pressure checked regularly (work w physician)
-be aware of risk factors & warning signs of diabetes (work w health care professional)

Digestion of Lipids

-lipids reach the stomach unchanged, mechanical digestion & gastric lipase chemically digests fats (minimal)
-presence of fat in sml intestine stimulates the release of bile from the gall bladder
-bile emulifies fats in order to ↑ surface area for digestive enzymes
-pancreatic lipase breaks up triglycerides into fatty acid & glyceride which are absorbed into the cells in the intestinal wall

Absorption of Lipids

-95% consumed fat is absorbed - 5% is excreted in faces
-sml fat molecules are surround by bile salts & dissolved in the sml intestine before being absorbed into intestinal cells→blood stream→liver

Metabolism of Lipids

-once in blood stream, lipids must be transported to body cells by lipoproteins (lipid+proteins produced by liver & sml intestine)
-used for ATP or stored in adipose tissue
-Lipoproteins are classified according to the ratio of lipids to protein
-4 major categories, chylomicrons, very low density (VLDL), low density (LDL), high density (HDL)

Fats & Healthy Eating

-20-35% cal in food/day
-limit saturated & trans-fat (less solid fat)
-choose oils not solid fat
--monosaturated
--omega-3 fats (2-3 times/week)
-minimize cholesterol intake

High Fat Diets...

can lead to:
-Cardiovascular disease
-Cancer
-Obesity

Low Fat Diets...

-are not for everyone!
-certain medical conditions require diets higher in fat e.g. renal failure pts, elderly, anorexia nervosa
-children under 2 yrs - require ↑ fat for development

Protein

-lrg complex molecules composed of amino acids (AA)
-20 common types (must be available for cells to synthesize proteins)
--9: essential via food
--11: synthesized by liver
-b/c of its nitrogen content, protein is used as a building source for new body cells

Digestion review

-begins in the stomach where:
--HCL denatures proteins
--enzyme pepsin breaks down protein into polypeptides & some AAs
-Then the sml intestine:
--site of most protein digestion
--pancreatic protease ↓ polypeptides to smller chains & AAs
--peptidases break the remaining peptide bonds to produce AAs

Absorption & Metabolism

-absorbed by intestinal mucosa w the aid of Vit B6
-released into the blood stream to the liver
-liver distributes AAs to the cells as required or stores them

Nitrogen Balance

-reflects the state of balance btwn protein breakdown & protein synthesis
Positive nitrogen balance: when protein synthesis exceeds protein breakdown
-too much nitrogen
Negative nitrogen balance: an undesirable state that occurs when protein breakdown exceeds protein synthesis
-deficit of nitrogen

Proteins to Eat

-energy 4 cal/g
-12-20% of total energy intake
-good sources: meats, poultry, seafood, dairy, eggs, soy, legumes, whole grains, nuts
-fruits & veggies have little protein
Complete: contain all 9 essential AAs
-all animal sources & soy
Incomplete: do not contain all 9 essential AAs
-plant proteins
-can be combined to ↑ overall nutrient value (complimentary proteins) e.g. black beans & rice

Vegetarian Diets (3)

1. Vegans: no animal products
2. Lacto-vegans: no animal products, except milk
3. Lacto-ovovegans: no animal products, except milk & egg

Health risks of Vegetarian Diets

-may lack essential nutrients
--deficit in: iron, protein, Vit. B12, Vit. D, Ca, Zn
-may consume excessive fat & cholesterol if relying heavily on dairy, eggs, nuts, etc.

↑ Protein Diets work b/c...

1. ↑ PRO foods stay in the stomach longer & promote feeling of fullness
2. Slow & steady effects on serum glucose levels, don't raise levels sharply like simple sugars so you don't feel as hungry
3. Body uses more energy to digest PRO than CHO

Health Risks of ↑ High Protein

-↑ PRO animal sources are usually ↑ in saturated fat & cholesterol
-↑ fat & cholesterol raise risk of CAD, stroke, CA
-Osteoporosis (digestion of PRO requires Ca+ - may be pulled from bones)
-do not provide some essential vitamins, minerals, fibre & other nutritional elements
-↑ risk for kidney & liver disorders

Protein Disorders (3)

1. Sickle cell anemia:
-recessive genetic disorder, missing protein causes RBCs to be misshapen, hard & sticky
-↑ clogging & breakage
2. Cystic Fibrosis:
-genetic disorder caused by an abnormal protein that prevents passage of Cl- in & out of certain cells (affects respiratory & GI)
3. PKU (phenylketonuria):
-genetic disease where a specific enzyme is missing that is required to break down the AA phenylalanine
-built up phenylalanine results in brain damage

Protein-Energy Malnutrition (PEM)

-d/t chronic & inadequate protein & energy requirements
-associated w developing countries
-In Canada, associated w AIDS, CA, homeless, eating disorders, drug & alcohol addicts
-reduced albumin (<3.5 mg/dL) related to impaired body processes
-Kwashiorkor: condition of PRO deficiency, results from acute critical illness
-Marasmus or protein-calorie malnutrition (PCM): occurs 2° to chronic diseases

Risk Factors for Obesity

-↑fatty & sugar foods
-↓fruit & veggies consumption
-↑portion sizes
-↓physical activity (sedentary lifestyle)

Complications of Obesity

-insulin resistance, type 2 diabetes, hypertension, dyslipidemia (↑blood cholesterol), CVD, stroke, gallstones & cholecystitis, sleep apnea, respiratory dysfunction, ↑incidence of certain CA
-a modest wt loss of 5% to 10% of initial body wt is associated w significant improvements in blood pressure, cholesterol & plasma lipid levels & blood glucose levels

Leading causes of death associated with Obesity (6)

1. Coronary Heart Disease
2. Cancer
3. Stroke
4. Chronic lower respiratory diseases
5. Diabetes
6. Accidents (unintentional injuries)

Body Fat Distribution

-Android obesity: fat is located largely in the waist & abdomen "apple-shaped"
--associated w ↑risk of heart disease, hypertension, & Type II diabetes
--fat goes straight to the liver via the portal vein & made into LDL (lousy) = ↑atherosclerosis
-- encouraged by ↑testosterone
-Gynecoid obesity: fat deposits are located primarily below the waist in the hips & thighs "pear-shaped"
--health risks are < than those associated w Android Obesity
--encouraged by Estrogen & Progesterone

Hunger

-controlled by internal body mechanisms
-organs such as the brain & liver interact w hormones, the nervous system, & other aspects of body physiology to influence eating behaviour
-hypothalamus: the satiety regulator
--the hormone leptin (linked to adipose tissue) regulates eating behaviour
--↑ adipose tissue = ↑leptin →satiety (full to satisfaction)
--Ghrelin (a protein) acts as a hormone to ↓energy expenditure & ↑appetite
--produce by the stomach cells
--triggers the desire to eat

Exercise

-essential to wt loss
-maintenance of wt
-lowers rates of morbidity/mortality

Drug therapy

-appetite suppressants
-nutrient absorption (blocking drugs)
-drugs will not cure obesity
-evaluation of other medical conditions

Surgical Intervention

-most effective Tx for severe obesity
-appropriate for clients whose BMI is 35-39.9
Works by:
1. Restricting the stomach's capacity
2. Creating malabsorption of nutrients & calories
3. A combination of both

Laparoscopic adjustable gastric banding (LAGB)

-inflatable band encircles the uppermost stomach & is buckled
-sml pouch of 15-30mL capacity is created w a limited outlet btwn the pouch

Gastric Bypass

-stapling stomach to create 30-45mL gastric pouch
-create upper & lower pouch & disconnecting pouches
-create upper pouch & removing lower pouch
-greatest rate of wt loss during 1st year (stabilizes after 18 months
-Dumping Syndrome (side effect): rapid emptying of the stomach contents into the sml intestine
--occurs 10-20min postprandially (after a meal)
--S&S nausea, & abdominal distention, flatulence, pain, diarrhea, &/or tachycardia, postural hypotension, weakness, syncope (fainting)
-deficiency of iron, calcium, vitamin B₁₂

Eating Disorders vs Disordered Eating

Eating Disorder: psychiatric condition involving extreme body dissatisfaction & long term eating patterns harming the body
-Anorexia Nervosa
-Bulimia Nervosa
Disordered Eating: variety of abnormal or atypical eating behaviours used to reduce wt
-Binge-Eating
-Chronic Dieting

Anorexia Nervosa

-↑ mortality: electrolyte imbalance
-medical disorder in which unhealthy behaviours are used to maintain a body wt < 85% of expected wt
S&S:
-extremely restrictive eating practices
-tooth decay
-self-starvation
-intense fear of wt gain
-amenorrhea: no menstrual periods for min 3 mths
-unhealthy body image

Anorexia Nervosa Health risks

-electrolyte imbalance
-cardiovascular problems
-gastrointestinal problems
-bone problems leading to osteoporosis

See More

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