Week 2 Flashcards
exchange systems
can be useful for diet planning
- foods are in “exchanges”
- can exchange 1 slice white bread for 1 large peach
exchange system for calorie control
weight watchers
exchange system for controlling carbohydrate intake
diabetes
two ways nutrition facts table presents information
- absolute quantities (grams)
- percentages of standards (% daily values)
daily values
based on recommended daily intakes for vitamins and minerals or reference standards for carbs, protein, fats , fibre, sodium
2 types of daily values
- some suggest intake goal to strive for, such as those for fibre, protein, vitamins and most minerals
- others constitute daily Maximums, for cholesterol, total fat, the sum of saturated and trans fat and sodium
% of daily values
the calculations used to determine the “% daily value” based on a 2000-calorie diet
- food contains a little (5% DV or less) or a lot (15% DV or more) of a nutrient
two types of nutrition claims
- nutrient content claims
- health claims
nutrient content claims
may highlight a nutrition feature of food such as light, low, less, free
ex. “low-fat feta”
health claims
include two different types of claims
1. disease reduction claims
2. function claims
subset of function claims
nutrient function claims
nutrient content claims
must meet criteria for specific claims defined by Canadas food and drug regulations
ex. “cholesterol-free” or “source of fibre”
examples of nutrient content claims
- free
- sodium free (less than 5 mg)
- cholesterol free (less than 2mg)
- low
- low fat (3g or less)
- low in saturated fat (2g or less)
- very high fibre
- excellent source of vitamin C, potassium
- source of folate
disease reduction claims
link consumption of a food or ingredient and a persons health
- require a scientifically established relationship between diet and reduction in chronic disease
- restricted in Canada
examples of disease reduction claims
- sodium and potassium and link to high blood pressure
- calcium and vitamin D and link to osteoporosis
when can you make a health claim?
highly researched and very regulated
function claims
describe the roles of a food or food constituent has on the normal functions or biological activities of the body
ex. consuming 7 grams of fibre from coarse wheat bran promotes regularity
nutrient function claims
- type of function claims
- statements about the roles of energy or nutrients that are essential for good health or normal growth and development
ex. Vitamin D helps build strong bones
nutrient facts table
lists kcals and 13 core nutrients
- ended december 14, 2022
changes that were made to the food labels
- making serving sizes more consistent (easier comparison)
- revising % daily value
- adding new % daily value for total sugar
- adding potassium to required nutrients
- removing vitamin A and C
- adding mg for calcium, potassium and iron
- adding a footnote at bottom about % daily value
changes to the way sugars are listed on food labels
grouping sugars-based ingredients in brackets after the name ‘sugars’
- gives a more accurate picture of amount of sugar
types of sugars
- white, beet, raw, brown
- agave syrup, honey, maple syrup, barley malt extract or fancy molasses
- fructose, glucose, glucose-fructose, maltose, sucrose, or dextrose
- fruit juices concentrates and puree concentrates that are to replace sugars in foods
when to use the ingredient list
- to check if a food product has a certain ingredient
- identify sources of nutrients, such as sugars
- to avoid a food product in case of food allergy or intolerance
- understand how much sugar is in the food compares to other ingredients
how are ingredients listed
from most to least by weight
foods usually exempt from carrying a nutrition facts table
- alcohol
- fresh fruits and veggies
- refillable glass dairy containers
- very small packages, such as one-bite candy
- raw, single ingredient meat, poultry, fish and seafood (except ground meat)
- herbs and spices
- farmers market foods
- sandwich or muffins in plastic wrap
front-of-packaging nutrition labelling
required on foods high in sodium, sugars or saturated fats as of january 1, 2026
rational for front-of-packaging nutrition labelling
- frequent intake in foods high in sodium, sugars, or sat fat is linked to increased health risks
- helps shoppers make fast, informed choices
- support health professionals in educating Canadians
calories of food menus at restaurants
food-service chains with 20 or more locations in ontario are required to post the number of calories in standard food and drink items they sell as or january 1, 2017
where you will see calories on menus in ontario
- fast-food restaurants
- restaurants
- coffee shops
- bakeries
- grocery stores
- movie theatres
phytochemicals in foods
significants effects
1. sensory properties
2. acting as antioxidants
3. mimicking hormones
4. altering blood constituents in ways that may protect against some diseases
phytochemicals and toxins
supplements of phytochemicals can be toxic when taken in too high a dose
foods rich in phytochemicals
- whole foods
- wine
- tea
- chocolate
- soybeans
- flaxseed
- tomatoes
- garlic
chocolate
- a flavonoid antioxidant in dark chocolate may reduce blood-clotting tendencies
- high in sugar and saturated fat
- occasional treat for antioxidant phytochemicals
where are antioxidant phytochemicals best obtained from
- nutrient-dense, low-calorie fruits and veggies
- calorie-free green or black tea
how often should you eat tomatoes
5 tomato-containing meals per week equals a lesser likelihood of cancers of the esophagus, prostate or stomach
lycopene
may inhibit the reproduction of cancer cells and protect against damaging sun rays/skin cancer
what foods is lycopene found
- tomatoes (especially cooked)
- papaya
- watermelon
- pink grapefruit
garlic
contains organosulfur compounds reported to inhibit cancer development in lab animals
- investigating roles of garlic against allergies, heart disease, and bacterial cause of ulcers
- garlic power is disappointing
taste buds
guide you in judging what foods are acceptable
basic chemical tastes
- sweet
- sour
- bitter
- salty
- umami (MSG)
flavour vs taste
flavour: total sensory impression when a food is eaten
- aroma, texture, temperature, taste
taste: the 5 basic tastes
why do people like sugar, fat and salt?
people generally have taste aversions to bitter and sour tastes in isolation
- usually associate them with toxins
adequate energy intake with sugars, fats and salts
sugars: energy to brain
fats: energy and essential nutrients
enjoyment of salt: assures consumption of sodium and chloride
digestion
break molecules of food into smaller molecules
absorption
movement of nutrients into intestinal cells after digestion
the digestive tract
flexible muscular tube extending from mouth to anus
digestive system functions
- absorb nutrients
- absorb some non-nutrients
- not absorb some substances (fibre)
- digest food to its components, absorb and excrete (main function)
where does digestion begin?
the mouth
salivary amylase
enzyme that breaks down starch
lingual lipase
begins the digestion of fat
- minor role
saliva
- helps maintain the teeth
- neutralizes acids produced by oral bacteria and washes away food particles that would promote tooth decay
where does protein digestion begin?
the stomach
gastric juices
- released by the stomach
- mixture of water, enzymes, hydrochloric acid (HC1)
- activates a protein-digesting enzyme called pepsin
- acid begins the denaturation of proteins
how is the digestive tract protected from the acid?
mucus
- acid has very high acidity
where does most digestion and absorption occur?
the small intestine
hormonal messengers (cholecystokinin CCK)
stimulate the gallbladder to release bile into the intestine
bile
an emulsifier produced in the liver and stored in the gallbladder
CCK release
stimulated by fat or protein in the small intestine
- slows down gastric emptying
emulsifier
substance that helps mix two ummixable substances
hormonal messengers (secretin)
stimulate the pancreas to release pancreatic juice
pancreatic juice
contains enzymes and bicarbonate and water
- enzymes digest carbs, protein and fat (amylase, proteases, lipase)
- bicarbonate neutralizes stomach acid
when are nutrients able to be absorbed into the small intestine?
when they are in broken down into small enough pieces via pancreatic and intestinal enzymes
what remains in the digestive tract when nutrients are absorbed into the small intestine?
- water
- fibre
- some minerals
fibres
- cannot be digested by human enzymes
- some are digested by bacteria living in the digestive tract
food combinations and digestion
“food combining” diets underestimate the abilities of the GI tract
- some foods are handled better in combination
ex. vitamin C helps iron absorption (keeps iron in ferrous form)
how does the digestive system digest food combinations
adjusts to whatever mixture of foods in presented to it
- pancreas is sensitive in adjusting
digestion in the mouth
food is chewed, mixed ad chemically broken down by teeth, tongue and saliva
- each swallow triggers peristalsis that moves food from the esophagus to the stomach
digestion in the stomach
- starch digestion is stopped by pH of stomach
- acid denatures proteins - enzymes then break them down
- end result is chyme
absorption of alcohol and drugs
some absorption occurs in the stomach
digestion in the small intestine
- some sugars are absorbed after entering SI
- bile emulsifies fat
- pancreatic enzymes break down starch, fat and protein
- cells of SI produce enzymes that complete chemical breakdown
- small fragments are absorbed into blood and lymph via the cells of SI wall
- vitamins and minerals are also absorbed
digestion in the large intestine (colon)
- fibre fragments, fluid and some minerals are absorbed
- fibres are partly digested by bacteria
- most fibre is not absorbed and is excreted as feces
microbiota
refers to mix of microbial species of a community, like in the digestive tract
how do microbes affect body systems
products of the bacteria may communicate with muscle, adipose tissue, the brain, immune system, etc.
probiotics
consumable products containing live micro-organisms in sufficient numbers to alter the bacterial colonies of the body in ways believed to benefit health
prebiotics
substances that may not be digestible by the host, such as fibre, but served as food for probiotic bacteria and thus promotes their growth
villi and microvilli
- projections that line the small intestine
- microvilli extend from the villi
- increases absorptive surface area
selective absoprion
absorption in the intestine is selective
- we absorb more when we need ti
- we absorb less when at risk for toxicity
absorption
- nutrients pass through the cells of villi
- blood and lymph then transport nutrients to body’s cells
blood vessels
transport most products of carbs and protein digestion, mopt vitamins and minerals to the liver
lymphatic vessels
transport most products of fat digestion
- later delivered to the bloodstream
poor nutrition and digestion
the digestion system is sensitive to poor nutrition
1. absorptive surfaces of SI atrophies with severe undernutrition
2. witihout adequate fibre the DTs muscles become weak from lack of exercise
3. malnutrition (under) impairs digestion and thus becomes self-perpetuating (vicious cycle)
potential problems with digestion
- belching, gas and hiccups
- heartburn (GERD)
- ulcer
- hernia
- choking
- dysphagia
- constipation
- diarrhea
- IBS
hiccups
spasms of the vocal cords and the diaphragm
- can be caused by irritation of the diaphragm, indigestion, etc.
gas
may be caused by air swallowed during eating, some veggies, beans, and milk products (lactose intolerant)
heartburn (GERD- gastroesophageal reflux disease)
- reflux of acidic stomach contents into esophagus
- acid burns the unprotected surface of the esophagus
how heartburn is caused
- laying down after a meal can open muscular sphincter allowing acid into esophagus
- excess abdominal fat can put pressure on stomach causing acid ro back up
potential contributors of the heartburn
- overeating
- coffee
- fat
- chocolate
- carbonated soft drinks
- alcohol
- smoking
- “hot” components of chili peppers
things that may help heartburn
- limit/avoid problem foods
- try eating smaller meals
- drink liquids an hour before or after eating (not during)
- wear loose clothing
- relax, but sit up, after eating
antacids
provide only temporary relief by neutralizing stomach acidity
- body responds by producing more acid to restore normal acid conditions
- can interfere witH ability to absorb nutrients
- can indigestion and diarrhea
- can mask symptoms of an ulcer or GERD
untreated GERD
may increase risk of esophageal cancer
- Barretts esophagus
treatment for GERD
may require surgery or management with medication
ulcer
an erosion in the layers of cells that form a lining
- the bacterium that causes stomach ulcer may also have a role in stomach cancer
- treatment involves antibiotics
hernia
a protrusion of an organ or body part through the wall of the body chamber that normally contains the organ
- can cause food to back up in the esophagus
- may require surgery
choking
food is lodges in the trachea and blocks the passage of air
dysphagia
difficulty swallowing
- seen in people with ALS, parkinsons or following a stroke
constipation
infrequent difficult bowel movements
- often caused by diet, inactivity, dehydration, or medication
- chronic constipation associated with increased risk of colon cancer
prevention of constipation
- defecate when needed (waiting leads to more water being extracted from feces, making feces harder)
- consume sufficient fibre to create softer, bulkier stools that stimulate muscle contraction
- drink fluids
- be physically active
diarrhea
frequent watery bowel movements
- severe prolonged diarrhea casues dehydration and mineral imbalances
- important to drink plenty of fluids with diarrhea
what causes diarrhea?
- diet
- stress
- irritation of colon
irritable bowel syndrome (IBS)
intermittent disturbance of bowel function caused by frequent bouts of diarrhea and constipation
- may be associated with diet, lack of PA or psychological stress
- low FODMAP diet
inflammatory bowel disease (IBD)
chron’s and colitis
- inflammation anywhere in the GI tract
the excretory system
waste must be eliminated
- some wastes are pulled out of the blood by the liver
liver processing wastes
- sends them to digestive tract with bile, to leave the body with feces
- prepares them to be sent to the kidneys for disposal in the urine
kidneys
- waste and water removal specialists
- filters blood
- regulates fluid volume and concentrations of substances in blood and extracellular fluids
what is the kidney function regulated by
hormones
excretion or retention of sodium
done by the kidneys and is a vital part of the body’s blood pressure-controlling mechanism
excess energy-containing nutrients
stored in 2 forms
1. glycogen
2. fat
glycogen
storage of some excess carbohydrates
fat
storage of excess fat, protein, and carbs
- liver ships out fat in packages to be picked up by cells that need it
what is excess fat stored in
the cells of adipose tissue
glucose and fat storage systems
ensure the body cells will have a source of energy
other nutrient stores
- some nutrients are stored without limit, even if they reach toxic levels (vitamin D)
- other nutrients are stored in only small amounts and can be readily depleted if not replenished (vitamin C)r
