unit 7: nutrition Flashcards
nutrition
science of food and how the body uses it in health and disease
-act or process of nourishing or being nourished
essential nutrients (6)
substances the body must get from foods bc it cannot manufacture them at all or fast enough to meet its needs; include proteins, fats, carbs, vitamins, minerals, and water
macronutrients
essential nutrients required by body in relatively large amounts
-protein, fat, carbs
micronutrients
essential nutrients required in minute amounts
-vitamins and minerals
protein
-4 cal/g
forms important parts of muscles, bone, blood, enzymes, hormones and cell membranes
-repair tissue
-regulate water and acid-base balance
-help in growth
-supply energy
-meat, fish, poultry, eggs, milk products, legumes, nuts
carbs
4 cal/g
-supply energy to cells in brain, nervous system, and blood; supply energy to muscles during exercise
-grains (breads and cereals) , fruits, vegetables, milk
fats
-9 cal/g
-supply energy
-insulate, support, and cushion organs; provide medium for absorption of fat-soluble vitamins
-animal foods, grains, nuts, seeds, fish, vegetables
vitamins
-promote (initiate or speed up) specific chem rxns within cells
-abundant in fruits, vegetables, and grains
-found in meat and milk products
minerals
-help regulate body functions
-aid in growth and maintenance of body tissues
-act as catalysts for release of energy
-found in most food groups
water
-makes up approx 60% body weight
-provides medium for chemical rxns
-transports chemicals
-regulates temp
-removes waste products
-fruits, vegetables, liquids
calories
expressed in kilocalories
-amount of heat it takes to raise the temp of 1L by 1 degree celsius
-energy needs is 2000 kilocals
amino acids
building blocks of proteins
-20 common aa in food; 9 are essential
-histidine, isoleucine, leucine, lysine. methionine, phenylalanine, threonine, tryptophan, valine
- other 11 are produced by the body
complete protein
supplies all the essential amino acids in adequate amounts
-meat, fish, poultry, eggs, milk, cheese, and soy
-certain combos of vegetable proteins allow each vegetable to make up for amino acids missing in the other protein
incomplete proteins
does not supply all essential amino acids in adequate amounts
-legumes (peas, lentils and beans), nuts
vegetable protein
-hemp
-chia seeds
-quinoa (2g protein/ 1/2 cup)
-dont have as much protein as legumes, meats . fish or poultry
recommended protein intake
0.8 g/ kg of body weight
-abt 50g of protein per day for smo who weighs 63 kg and 65g protein for 81 kg
-10-35% total daily caloric intake
-high protein intake strains kidneys
types of fat + source
-linoleic acid + alpha linoleic acid –> key regulators of blood psi and progress of a healthy pregnancy
-triglyceride: glycerol + 3 fatty acid chains (EX. ANIMAL FAT)
- can be saturated, unsaturated, polyunsaturated, monounsaturated due to differences in fatty acid structure
-food fat: saturated, unsaturated
saturated fatty acids
-solid at room temp
-found naturally in animal products
-red meats, homogenized milk, cheese, hot dogs, and lunchmeats
monounsaturated /polyunsaturated
-come from plant sources
-liquid at room temp
-mono: olive, canola, safflower, and peanut oils
-poly: soybean, corn, cottonseed, fish oil
hydrogenation
-hydrogens are added to unsaturated fats, increasing degree of saturation and turning liquid oils into solid fats
- produces a mixture of saturated fatty acids and standard and trans forms of unsaturated fatty acids
-can increase stability of oil so it can be reused
-improves the texture of certain foods
-extends the shelf life of foods made w/ oil
-transforms a liquid oil into margarine or vegetable shortening
-the more solid a hydrogenated oil is , the more saturated and trans fat it contains
–> vegetable oils, palm and coconut oils
trans fatty acids
a type of unsaturated fatty acid produced during hydrogenation
-have an atypical shape and affects their chemical activity
-in processed foods (hard margarines, crackers, cookies, cakes, doughnuts, pastries, muffins, croissants, snack foods, fried foods, breaded foods
cholesterol
a waxy substance in blood and cells and needed for synthesis of cell membranes, vitamin D and hormones
LDL
-bad cholesterol
-saturated and trans fatty acids
-increases risk of heart disease
-unsaturated fat lowers LDL
HDL
monounsaturated acids (olive/canola oils)
-large amounts of saturated fat will lower HDL
–> impairs ability of HDLs to prevent inflammation of blood vessels, also reduces ability of blood vessels to react normally to stress
heart health
-moderate intake of saturated and minimize trans fat
- lower intake intake of meat and full fat dairy products (homogenized milk, cream, cheese, butter, yogurt, ice cream)
-decrease intake of deep-fried foods/processed foods
-the softer/ more liquid a fat is, the fewer saturated/trans fat it contains
omega-3 fatty acids
-form of polyunsaturated fat found in fish
-contain essential nutrient alpha-linolenic acid
-reduces the tendency of blood clotting, inhibit inflammation + abnormal heart rhythms, reduces blood psi, and risk of heart attack and stroke
- eat at least 2x a week
-salmon, tuna, trout, mackerel, herring, sardines and anchovies
-dark-green leafy vegetables, walnuts, flaxseeds,
-canola, walnut and flaxseed oils
omega 6 fatty acids
-polyunsaturated fat
-corn oil and soybean oil
-contains essential nutrient linoleic acid
-omega 3 is recommended
-might lower HDL levels and increase risk of cancer
recommended fat intake
men: 17 g of linoleic acid, 1.6 g of alpha linoleic acid
women: 12 g of linoleic acid, 1.1 g of alpha linoleic acid
-30-45ml (2-3 tablespoons) of unsaturated fat per day incorporated into diet
AMDR
-acceptable macronutrient distribution ranges
-ensuring adequate intake of essential nutrients while also reducing the risk of chronic diseases (heart disease and cancer)
-20-35% of total cals
-omega 3 –> 0.6-1.2%
-omega 6 –> 5-10%
-saturated/trans fat: as low as possible + most fat should be unsaturated
types of carbs
simple: sucrose, fructose, lactose
- sweetness in foods found naturally in fruits and milk and usually added to other foods
complex: starches and most types of dietary fibre
-starches found in plants esp grains (wheat, rye, rice, oats, barley, millet), legumes, and tubers (potatoes, yams)
-can be a mixture of complex and simple carbs in other vegetables
digestion of carbs
-carbs breakdown into simple sugar molecules (glucose) for absorption
-pancreas releases insulin and allows cells to take up glucose to use for energy (problems controlling glucose lvls leads to diabetes)
-liver and muscles take up glucose to provide carb storage in the form of glycogen
types of complex carbs
-refined or processed or whole grains (entire edible portion of a grain, wheat, rice, or oats, consisting of the germ, endosperm, and bran. during milling or processing, parts of the grain are removed and often leaving just the endosperm)
refined carbs
-usually retain all the calories of unrefined counterparts–> tend to be lower in fibre, vitamins, minerals, and other beneficial compounds
-enriched or fortified w/ vitamins and minerals, but nutrients lost in processing are not replaced
-minimal/ no nutritional value
-added sugar –> risk of cardiovascular disease
-white bread, rice
unrefined carbs
-take longer to chew/digest –> enters bloodstream more slowly
-slower rise in blood glucose lvls which helps management of diabetes
-whole grains are high in dietary fibre and carry all benefits
–> reduced risk of heart disease, diabetes, high blood psi, stroke and certain forms of cancer
-whole wheat bread, brown rice
glycemic index
-a measure of how the ingestion of a particular food affects blood glucose lvls
-high: may increase appetite and long term increases risk of diabetes and heart disease
recommended carb intake
45-65% of total daily cals
-225-325 g of carbs for smo consuming 2000 cals
-less than 5% for sugar intake per day (25g)
athletes: 60-70% total daily cals) –> enhances amount of carbs stored in muscles (as glycogen) and have more carb fuel for endurance
-helps fuel muscles and extend availability of glycogen
-overconsumption: fatigue and underconsumption of other nutrients
fibre
-non-digestible carbs provided by plants
-passed through intestinal tract and provides bulk in feces
-not a source of carbs
types of fibre
-dietary: non digestible carbs presented naturally in plants (grains, legumes, and vegetables
-functional: non digestible carbs that have been either isolated from natural sources or synthesized in a lab and added to a food product or dietary supplement
total fibre: sum of dietary and functional fibre
soluble fibre: dissolves in water or is broken down by bacteria in large intestine (oat bran or legumes)
-delays stomach emptying, slows movement of glucose in blood, reduce absorption of chol
insoluble fibre: found in wheat bran or psyllium seed
-increases fecal bulk and helps prevent constipation, hemorrhoids and other digestive disorders
sources of fibre
-all plant foods
-fruits, legumes, oats, barley –> viscous type of fibre that lowers blood sugar and chol lvls
-wheat, grains, cereals and vegetables –> good sources of cellulose and other fibres that prevent constipation
-psyllium: used in fibre supplements/laxatives and added to cereals –> improves intestinal health and controls glucose/chol lvls
-processing of packaged foods removes fibre
-fresh fruits and vegetables and foods from whole grains as main sources of fibre
fibre health benefits
-reduces risk of type 2 diabetes and heart disease
-reduced risk of colon/rectal cancer
recommended fibre intake
-38 g for adult men (19-50; 30g/day for men 51 and older)
-25 g for adult women (19-50; 30g/day for women 51 and older)
-should come from foods not supplements
vitamins
-organic (carbon-containing) substances required in small amounts to regulate various processes within living cells
humans need 13 vitamins; 4 are fat soluble (A, d, e , k) and 9 are water soluble ( C, and 8 b-complex vitamins: thiamine, riboflavin, niacin, b6, folate, b12, biotin, pantothenic acid)
solubility of vitamins
-water-soluble: directly into bloodstream and can travel freely; excess are detected and removed by kidneys and excreted in urine
-fat-soluble: usually carried in the blood by special proteins and are stored in the liver and in fat tissues rather than excreted
functions of vitamins
-help chemical rxns take place
-dont provide energy but help unleash energy from carbs, proteins and fats
-critical in production of rbc and maintenance of nervous, skeletal and immune systems
antioxidants
-substances that lessen the breakdown of food or body constituents by free radicals; binding o2, donating electrons, repairing dmg to molecules)
-preserve healthy cells in the body and reduce /remove formation of free radicals
-vitamin E, C and A precursor beta-carotene
-blackberries, walnuts, strawberries, cloves, grape juice, unsweetened baking chocolate, sour cherries, red wine, brewed coffee, raspberries, pecans, blueberries
sources of vitamins
-abundant in fruits, vegetables, and grains, processed foods (added vitamins)
-skin makes vitamin d when exposed to sunlight, intestinal bacteria make vitamin K
vitamin deficiencies
-scurvy: lack of vitamin C
-rickets: lack of vitamin D, diabling bone deformations
-blindness: lack of vitamin A
-seizures: lack of vitamin B6
-heart disease: low intake of folate, vitamin B6 and B12
-bone brittleness/bone fractures: lack of vitamin K
lack of vitamin D
-rickets in children
increased risk of CVD
-increase of colorectal cancer
vitamin excesses
-fat soluble: excessed is just stored in body and not excreted so increase in toxicity
-vitamin D: kidney and tissue dmg
keeping nutrient value in food
vitamins and minerals can be lost or destroyed during storage and cooking of foods
-keep as fresh as possible
-store fruits and vegetables in covered containers or plastic bags to minimize moisture loss
-frozen or canned are high in nutrients
-minimize amount of water used and total cooking time
-develop a taste for crunchier texture in cooked vegetables
-baking, steaming, broiling, grilling and microwaving are healthy methods of preparing vegetables
minerals
-inorganic compounds needed in relatively small amounts for regulation, growth, and maintenance of body tissues and functions
-17 essential minerals: Ca, P, mg, na, k, cl
-essential trace minerals: Cu, Fl I, Fe, Se, Zn
poor calcium intake
osteoporosis (bones become dangerously thin and fragile over time)
functions of water
-digestion and absorption of food and is the medium which most chemical rxns take place
-water based fluids (blood) transport substances around the body, other fluids serve as lubricants or cushions
-regulates body temp
sources of water
almost all foods, liquids, fruits and vegetables
-80-90% of daily water intake + remainder is generated through metabolism,
recommended water intake
men: 3.7L of water
women: 2.7L of water
free radicals
-chemically unstable molecule that reacts w/ fats, proteins, and dna, dmging cell membranes and mutating genes
-implicated in aging , cancer, cvd and other degenerative disease such as arthritis
phytochemicals (plant chemicals)
-naturally occurring substances found in plant foods that may help prevent and treat chronic diseases (cancer and heart disease)
-substances in soy food may lower chol lvls, allyl sulphides (garlic and onions) boosts activity in cancer fighting immune cells, sulphoraphane (broccoli and other cruciferous vegetables; cabbage family)
DRI
dietary reference intakes
-recommended intake lvls
-role of nutrients in promoting health and preventing chronic diseases such as cancer, osteoporosis and heart disease
-standards for both recommended intakes and maximum safe intakes
RDA, AI, UL
recommended dietary allowance
-recommended intake of each nutrient
adequate intake
-set when not enough info is available to set an RDA value
tolerable upper intake lvl
- max daily intake that is unlikely to cause health problems in a healthy person
EAR
-estimated age requirement
-amount estimated to meet the nutrient needs of the half the individuals in a population group
–> calculates the RDA
daily values
-simplified rda used on food labels, includes values for nutrients with no rda
goal for fat intake
-total fat: 20-35% percent of total daily calories
-saturated fat: less than 7 percent of total daily calories
-trans fat: less than 2% of total caloric intake
-cholesterol: less than 300 mg per day
canada’s food guide
1942
-acknowledged the difficulties of coping w/ wartime food rationing while trying to prevent nutritional deficiencies and improve health
-reminding customers to make healthy food choices and to be active everyday and consuming a variety of foods
vegetarian
-lower un saturated fat and chol and higher in complex carbs, dietary fibre, folate, vitamins C and E, carotenoids and phytochemicals
vegans: plant only
lacto vegetarians: plant and dairy
lacto-ovo-vegetarians: plant, dairy, and eggs
-recommends eating more vegetable proteins: dry beans, nuts, seeds, eggs and soy foods
children and teenagers diet
-young ppl often simply need to be encouraged to eat
–> provided a variety of foods
-encouraged to select the healthiest choices from fast food menus and to complete the day’s diet w/ low-fat, nutrient rich foods
-allowing to help prepare meals
college and university students
- wide variety of foods
-make healthy choices - eat less food that is convenient
older adults
-become less active, require few calories to maintain body weight, and have lower absorption of nutrients
-consume nutrient-dense food to meet nutritional requirements
–> high in fibre and adequate fluids
athletes
-drinking enough fluids to remain fully hydrated
-increasing carbs in diet (complex)
-eating for exercise
low income families
-food insecurity
-use food banks and soup kitchens is harder to control the healthiness of diet
can be improved through public policies and a goal to improve financial realities
first nations, inuit, and metis
-community based and community delivered programs, initiatives and strategies aimed to improve health
ppl w/ special health concerns
-pregnant: require extra cals, vitamins and minerals
-diabetes: well balanced diet that is low in simple sugars, high in complex carbs and rich in monounsaturated fats
-high blood psi: need to control weight and limit sodium
NHP
-vitamins, minerals, herbal remedies, homeopathic medicines, traditional medicines, tcm, probiotics and aa and essential fatty acids
-needs to be regulated by the government
-needs a product license and is assigned a natural product number (NPN) or homeopathic medicine number (DIN-HM)
-exemption number (EN) means the product is not fully evaluated
food-borne illness
-caused by pathogens, disease causing microorganisms
-improper handling
-campylobacter jejuni (causes more cases of food borne illness than any other bacteria) –> food poisoning
-salmonella (raw eggs, poultry and meat, milk and dairy, seafood, fruits and veg)
-shigella (fecal contamination of food and water)
-escherichia coli (ecoli)
-listeria monocytogenes (soft cheeses, raw milk, hot dogs, lunchmeats
-staphylococcus aureus (sneeze or cough over food)
-noroviruses (cause gastroenteritis)
treatment: clear fluids to prevent dehydration and rest, wash hands often before handling food
environmental contaminants
-various minerals, antibiotics, hormones, pesticides, polychlorinated biphenyls, cyanogenic glycosides
-depend on conc, length of exposure, age and health status of the person involved
organic foods
-food must meet strict production, processing, handling and labelling criteria
-limits on pesticide residueand antibiotics/growth hormones
-genetic engineering, ionizing radiation, sewage sludge is prohibited
local foods and slow food
locally promotes benefits of buying agricultural products grown close to home
- supports local economy
-affordable and higher quality
slow food is a global movement of local groups and activists united by the common goal of ensuring everyone has access to good, clean and fair food.
fish consumption
-concern: mercury contamination
-found in predator fish
-explains why pregnant women should avoid fish
additives in food
-sugar, salt, corn syrup, citric acid, baking soda, vegetable colours, mustard and pepper
health concerns:
-nitrites and nitrates in red meat
-BHT and BHA (cancer)
-sulphites (allergic rxns)
-monosodium glutamate (MSG): increased BP and sweating
food irradiation
treatment of foods with gamma rays, x rays or high voltage electrons to kill pathogens
-doesnt completely sterilize foods
-reduces spoilage and extends shelf life
-raises skepticism bc of lack of info
GMO
-adding, rearranging or replacing genes in DNA
-benefits: improved yields, increased disease resistance, improved nutritional content, lower prices, less pesticide
-gene manipulation could elevate toxins or allergens, change the gene pool for good, produce insects that are resistent to pesticide
-no proof it is unsafe
animal cloning
-animals w/ highly desirable characteristics
-somatic cell nuclear transfer (SCNT)
-very limited data available
-unclear of impact in safety quality and raised food safety concerns
labelling of gm foods
-labelling is not required and is only required if a food’s composition is changed significantly or if a known allergen is introduced
-only foods guaranteed to not contain gm ingredients are those certified as organic
food allergy
An adverse reaction to a food or food ingredient in which the immune system perceives a particular substance (allergen) as foreign and acts to destroy it.
9 priority food allergens
peanuts
tree nuts
sesame seeds
milk
eggs
fish
soy
wheat
sulphites
mustard
food intolerances
An adverse reaction to a food or food ingredient that doesn’t involve the immune system; intolerances are often caused by a problem with metabolism.
-lactose, gluten (celiac disease), sulphite, msg, aspartame, tartrazine
