1
Q
Where do Carbs come from
A
Plants - whole grains, legumes, vegetables and fruit
Milk is the only animal derived significant carb - milk, yogurt and sour cream
Concentrated sugars : soft drinks, candies, cake
2
Q
Categorization of Carbs
A
Simple
- monosaccharides
- Disaccharides
Complex
- Polysaccharides
3
Q
Three types of monosaccharides
A
Glucose
Fructose
Galactose
They all have the same number and kind of atoms just arranged in different ways
4
Q
Glucose
A
Mildly sweet
essential for the body - especially the brain
ALWAYS one of the sugars in a disaccharide
Polys are almost always exclusively glucose
5
Q
Galactose
A
a component of milk sugar
not sweet
very rarely on its own, often paired with lactose
- on its own in fermented milk products (yogurt and aged cheese)
6
Q
Fructose
A
intensely sweet
Naturally occuring in fruits and honey
high fructose corn syrup is often in soft drinks, cereals and desserts (made from cornstarch which converts glucose - fructose)
7
Q
Types of disaccharides
A
Lactose = Glucose + Galactose
Maltose = Glucose + Glucose
Sucrose = Glucose + Fructose
8
Q
How are disaccharides split and combined
A
Hydrolysis reactions splits them and condensations reactions joins them giving off a water droplet
9
Q
Lactose
A
Milk sugar
Principle carb of milk
Provides about 1/2 the kcal in skim milk
10
Q
Maltose
A
produced during starch breakdown
Occurs during the process of alcohol fermentation
Only in some foods including barley
11
Q
Sucrose
A
Naturally occuring in fruits, vegetables and grains
Table sugar sucrose refined from beets or sugarcane
Brown sugar is just white with molasses added
12
Q
Digestion of sugars
A
Mono are absorbed directly into the blood
Dis are digested (split into mono) before absorbed
- if they’re not split = gas, diarrhea
13
Q
Sugar in fruit and vegetables
A
most of the energy from fruits and vegetables comes from sugar
The sugar here is different because fruits contain
- fibre
- phytochemicals
- vitamins and minerals
14
Q
Types of polysaccharides
A
Starch - bread, rice, potatoes
Glycogen - animal source starch
Fibre
15
Q
Starch
A
Storage form of glucose in plants
Can be branched (amylopectin) or unbranched (amylose)
Nutritive - because we can break it down to glucose for energy
Examples of foods - grains, Tubers (yams and potatoes), legumes (peas and beans)
16
Q
Glycogen
A
Storage form of glucose in animals
highly branched
Stored in muscle (2/3) and liver (1/3)
But when the animal dies glycogen quickly gets broken down
17
Q
Fibre
A
Found in vegetables, fruit, whole grains and legumes
Provide support and structure
Some retain water
pass through body without providing energy
- most - bacteria in Lg intest. can digest some to SCFA that the colon absorbs
17
Q
Does glycogen store lots of water
A
Yes
18
Q
Prebiotics
A
Foods that are not digested but promote bacterial growth by acting as its food
19
Q
Soluble Fibres
A
- dissolve in water
- Form gels
- Often fermented by bacteria in the colon
- Ex. barley, legumes, oat, apples, citrus, seaweed
- Associated with lower risk of chronic disease
- Slow glucose absorption
- soften stool
- used as thickening agents (pectin, gums)
20
Q
Insoluble fibre
A
- do not dissolve in water
- retain their structure and texture even after cooking
- ease elimination (constipation)
- do not form gels and rarely fermented
- ex. outer layers of whole grains and strings of celery (= cellulose..)
21
Q
why are carbs better than protein
A
less expensive
protein has no advantage when used as fuel
overuse of protein -> high saturated fat content
22
Q
AMDR - DRI committee recommendations for carbs
A
45-65% of daily kcal from carbs
23
Q
why must it be complex carbs for the 45-65%
A
- because they provided added nutrients
- Pure sugars are empty calories
- Overuse of sugars may alter blood lipids that may increase cardiovascular risk
- so increase fibre rich, whole foods
24
why are fibre rich foods recommended
Supply vitamins, minerals and phytochemicals
Contain little or no fat
Soluble fibres -> cholesterol lowering effect
Maintenance of healthy bowel functions
Modulation of blood glucose concentrations
25
How does a complex carb diet lower cholesterol and heart disease risk
soluble fibres bind cholesterol containing bile and cary it out in the feces, which forces the body to make additional bile from cholesterol in the body
These foods are naturally low in sat fat, trans fat and cholesterol
the small fatty acid produced from fermentation of soluble fats travels to liver where it helps reduce cholesterol synthesis
26
Carbs and glucose control
Soluble fats trap nutrients and delay their transit through the digestive tract, slowing glucose absorption and steadying levels of blood glucose and insylin
27
Carbs and maintenance of digestive tract
help maintain colon function and preventing and relieving constipation
- enlarge and soften stools
- speed passsage through intestine
- easier elimination
28
Fibre and constipation
Helps prevent compaction which can obstruct appendix and permit bacteria from invading
It stimulates muscles to retain their strength and resist bulging (diverticula)
29
Fibre and prevention of cancer
decreases rates of colon cancer
Dilute and speed removal of cancer causing agents from the colon
promote bacterial reproduction and binding of nitrogen and carrying it out of the body in feces
Plus the SCFA created from fermentation can help the colon resist chemical injury that leads to cancer
30
Carbs and weight management
complex carbs are generally low in fat and added sugars
Which provides less energy that can be converted to fat
Plus fibre helps with feelings of fullness and delays hunger (swells with water creating feeling of fullness)
31
Fibre recommendations and intakes
Females (AI):
19-50 = 25 g/day
51+ = 21 g/day
Males (AI):
19-50 = 38 g/day
51+ = 30 g/day
32
What are the three recommendations that increase fibre
1. Have plenty of fruits and vegetables
2. Choose whole grain foods
3. Choose protein foods that come from plants more often
33
Is too much fibre a thing?
Yes
Purified fibre can cause a blockage if there's not enough fluid
Some are chelating agents
Can lead to nutrient and energy deficiencies
Can remove water from the body contributing to dehydration
34
Parts of whole grains
Bran : made of cellulose, protects the grain, removed during milling
Endosperm : starch grains embedded in a protein matrix, used in refined flour
Germ : part where new grain develops, where the fat is found
35
Modern milling and its results
removes the germ and bran ultimately lowering the fibre content
Results in whiter and smooter = white bread but its causes a loss of nutrients
So now there mandatory addition of riboflavin, thiamin, niacin, iron, and folic acid
36
Digestion of Carbs : Starch
must be broken to mono
- Salivary amylase works in the mouth (denatured in the stomach)
- In the small intestine pancreatic ezymes split the starch into sm poly and dis AND intestinal enzymes split these into monosaccharides (which are now classified as sugars)
37
Absorption of starch
refined grains - are rapidly broken down into glucose and then absorbed
Cooked beans - are digested more slowly and release glucose later in the digestive process
38
Resistant starch digestion and absorption
behaves like fibre
Raw potatoes, unripe banaas
most remain intact until bacteria of the colon breaks it down
Sometimes even classified as insoluble fibre
39
Digestion and Absorption of Sugars
split into mono before absorbed (when we break down carbs = you get sugars)
Pancreatic amylase splits most starch to di
Sm poly and di are split by enzymes attached to cells lining the sm intestine
40
Examples of enzymes lining the sm intestine that break down sm poly and di sugars
Lactase
Sucrase
maltase
41
Where do sugars go once broken down
Absorbed into blood stream and travel to the liver
The liver and muscle cells store glucose as glycogen
42
Digestion and absorption of Fibre
Many fibres are fermented by intestinal bacteria
- Odorous gases are a bi-product
43
Lactose intolerance
Lactase production decreases with age
Lactase deficiency can also damage intestinal villi due to disease, malnutrition or prolonged diarrhea
symp because intestinal bacteria are left to ferment the undigested lactose creating gas and irritants
Symp include - N, pain, Gas, diarrhea
44
Milk allergy
is NOT lactose intolerance
its a reaction to the protein in milk
and so need non dairy options to help ensure sufficient calcium and V. D
45
DRI Committee Carb recommendations
the min intake to feed the brain and reduce ketosis is 130g/day (RDA)
AMDR = 45-65% of total energy to maintain health and glycogen stores
No glucose - leads to glycogen breakdown to create glucose-> gluconeogenesis using protein which breaks down muscle, enzymes and antibodies
46
If glucose levels are below a healthy minimum
fat cannot be converted to glucose
The body will use protein to make glucose
Ketone bodies form bc limited fat fragments that are derived from glucose resulting in ketosis disrupting acid base balance in the blood
47
Risk of chronic ketosis
V + M deficiencies
Loss of bone minerals (osteopenia, osteoporosis)
Altered blood lipids (high cholesterol)
Constipation, N + V
Glycogen stores too low to meet needs
48
Benefits of a ketogenic diet
reduce seizures in children
Neurological conditions such as Alzheimer
49
Insulin stimulates
uptake of glucose into cells
Storage of glucose into glycogen
Excess glucose into fat
(released a high blood glucose levels)
50
Glucagon stimulates
breakdown of glycogen therefore glucose is released into bloodstream
51
What does epinephrine do in times of danger
it breaks down glycogen in the liver as part of the body's defense mechanisms to increase glucose levels
52
Glycemic index
is the measure of the ability of a food to elevate blood glucose and insulin levels
Scored against standard (usually white bread)
The higher the score the higher the spike in blood sugar
- available sugar foods are often high whereas carb foods with fat or fibres mixed in slow absorption
53
Excess glucose
is stored as glycogen
2/3 of bodys total glycogen is stored and used by muscle
the remainder is in the liver with a small emergency store for the brain
54
Drugs for T2D :
May stimulate insulin secretion
May improve tissue uptake of glucose
External source of insulin may also be used
55
T2D and genetics
There is a genetic component to it
some individuals are more susceptible
56
T2D and weight
Generally, increased weight increases insulin resistance which increases blood glucose levels
Even being moderately overweight can lead to impaired glucose tolerance (slightly elevated blood glucose)
57
Impaired glucose tolerance
blood glucose levels higher than normal but not high enough to be diagnosed as diabetes
= prediabetes
58
The best diet for diabetes and weight
adequate nutrients
adequate fibre
Moderate added sugars
Controlled total carbs
Low sat fats
adequate protein
59
What dietary patterns help with glycemic control and are considered for T2D
Mediterranean style
Vegan or Vegetarian
DASH
Dietary patterns that emphasize dietary pulses (beans, peas, chickpeas)
Patterns emphasizing fruit and vegetables
Patterns emphasizing nuts
60
Hypoglycaemia and its types
= low blood glucose
Postprandial = low blood glucose after a meal
Fasting = occurs after fasting
- may be seen with cancer, pancreatic disease, diabetes, liver damage
61
How to avoid hypoglycaemia
Avoid switching between low carb dieting and sudden large carb doses
Avoid alcohol
62
What can cause hypoglycemia in diabetics
Physical activity (more than usual without sufficient fuel)
Not eating on time
Eating less than you should
Insulin dosing
Alcohol
63
Ways to treat Hypoglycemia
Eat or drink a fast acting Carb (15g)
- 15g of glucose (glucose tablets)
- 15 mL (one tablespoon) / 3 packets of table sugar dissolved in water
- 150 mL (2/3 cup) of juice/soft drink
- 6 Life savers
15 mL (one tablespoon) of honey
Check again 15 min later, if still low treat again until above 4 mmol/L
if more than one hour until next meal eat a snack
do not drive for 40 min
64
AMDR carb recommendations (DRI) Vs WHO
45-65%
RDA says that min 130 g/day
WHO says 55-75%
65
Free sugars
mono and di added to foods and beverages by the manufacturer, cook or consumer
AND
the sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates
66
Added sugars
all sugars added to foods and beverages during processing or preparation
(all added sugars are also free sugars)
67
Total sugars
Accounts for all sugars present regardless of the source
68
Sugar recommendations
Vary between groups with the lowest being 10% of total kcal
69
What can sugar be replaced with
Energy-yielding sugar alcohols
- nutritive sweeteners = which have calories but very few
No energy artificial sweeteners
- non nutritive (no calories)
70
Sugar alcohols
do not contain ethanol
Provide energy
Low glycemic response
Can cause gas, abdominal discomfort in high quantities
Do not contribute to dental caries
Naturally found in fruits and vegetables
manufactored from common sugars
71
Examples of Sugar alcohols
Erythritol
Isomalt
Lactitol
Maltitol
Mannitol
Sorbitol
Xylitol
72
do alternate sweetners promote tooth decay
No
73
Can alternative sweeteners be toxic at high levels
Yes
74
Examples alternative sweeteners
Aspartame
Steviol glycosides (stevia)
Sucralose
75
Aspartame
is 200x sweeter than sucrose
Not heat stable
Made of phenylalanine and aspartic acid and a methyl group
- metabolized like any protein
BUT
has by products including methyl alcohol, formaldehyde and diketopiperazine (NOT toxic at the levels which we consume it)
4 kcal/gram = IT HAS ENERGY
76
Aspartame and PKU
bc PKU = hereditary inability to dispose excess phenylalanine
- its build up is dangerous
- newborns are always tested for PKU
77
Canada and Sweetners
There's a lot of talk that they're dangerous but it takes a lot of evidence and testing for it to be accepted in canada
- moderation is key
- using them doesn't automatically lower energy intake
78
Alcohol quantities (Standard drinks)
Beer = 5% = 341 mL (12 oz)
Cider/Cooler = 5% = 341mL
Wine = 12% = 142mL (5 oz)
Distilled = 40% (80 proof) = 43mL (1.5 oz)
13.6 g of alcohol = 0.5 oz
79
Alcohol vs ethanol
Alcohol = class of organic compounds containing a hydroxyl group
Ethanol = the alcohol we consume
- a legal non prescription drug that produces euphoria
80
What happens when alcohol enters the body
enters cells and causes destruction which can ultimately kill the cell
Alcohol is toxic in relatively sm quantities
81
Alcohol and absorption
alcohol requires no digestion it can diffuse through the stomach wall and reaches the brain a min
Full stomach helps limit alcohol absorption and delays gastric emptying (so less reaches the sm intestine- slower)
Most is absorbed in sm intestine - once in the intestine food intake is irrelevant
82
Alcohol dehydrogenase (ADH)
Made by the stomach
Females have less as such absorb more alcohol
Its a protective measure
BUT fasting promotes ADH breakdown
83
How is alcohol metabolized
The liver does most with ADH doing 10%
10% is excreted in breath and urine
Alcohol increases urine output - because it decreases the production of the antidiuretic hormone
84
Excess hormone levels
If it exceeds what the liver can handle the alcohol circulates through the body and affects other areas and the brain
85
MEOS
another system in the liver that metabolizes alcohol and some drugs
about 10%
Handles more in high concentrations or repeated exposure
Results in better tolerance
Will do alcohol first if taken alongside a drug but this causes the drug to build up and its effects are amplified
BUT a heavy drinker will handle drugs better when not drinking
86
is alcohol a stimulant
NO
it can relieve inhibitions
BUT it SEDATES some inhibitory nerves thereby allowing excitatory nerves to take over
87
How does alcohol impact the brain**
IN ORDER:
- frontal love - judgement and reasoning
- speech and vision sedated
- Large muscle control is affected
- conscious brain is completely subdued and the person passes out
- deepest brain - respiratory and heart rate
88
NURS 100
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