Chapter 4 Flashcards
Refined
Foods that have undergone processes that change or remove various components of the original food
- more refined consumption than ever
- 13% of calories consumed come from added sugars in desserts, beverages, and prepared snacks
Whole grain
Bran
Germ
Endosperm
The entire kernel of grain, including the bran layers, the germ and the endosperm
The protective outer layer of whole grains. It is a concentrated source of dietary fibre
The embryo of sprouting portion of the kernel of grain, which contains vegetable oil, protein, fibre and vitamin E
The largest portion of a kernel of grain, which is primarily starch and serves as a food supply for the sprouting seed. also contains protein
Fortified or enriched grains
Grains to which specific amounts of thiamin, riboflavin, niacin, and iron have been added.
Free sugars
Added sugars
Monosaccharides and disaccharides added to food during processing and also the monosaccharides and disaccharides in honey, syrups and fruit juices
Also known as added sugars: Sugars and syrups that have been added to foods during processing or preparation
Simple carbohydrates
Complex carbohydrates
Carbs known as sugars that include mono and di saccharides
Polysaccharides: Carbs composed of monosaccharide molecules linked together in straight or branching chains. Include glycogen, starches and fibres!!!
Glucose
A monosaccharide that is the primary form of carbohydrate used to provide energy in the body. It is the sugar referred to as blood sugar
Galactose
A monosaccharide that combines with glucose to form lactose or milk sugar
Fructose
A monosaccharide that is the primary form of carbohydrate found in fruit
Sucrose
A disaccharide that is formed by linking fructose and glucose. Commonly known as table sugar or white sugar
Lactose
A disaccharide that is formed by linking galactose and glucose. Commonly known as milk sugar
Maltose
A disaccharide made up of two molecules of glucose. It is formed in the intestines during starch digestion
Hydrolysis reaction
A type of chemical reaction in which a large molecule is broken into two smaller molecules by the addition of water (break sugars)
Condensation reaction
A type of chemical reaction in which two molecules are joined to form a larger molecule and water is released (form sugars)
Polysaccharides (complex carbohydrate)
Complex carbohydrates made up of many monosaccharides linked in chains. Generally not as sweet to the taste
Include glycogen in animals and starch and fibre in plants
- glycogen (more branched), human digestive enzymes can break the bones. Found in liver and muscle (meat)
- starch and fibre (human digestive enzymes can break the bonds between glucose units in starch but not in fibre or cellulose.
Oligosaccharides
Short-chain carbohydrates containing 3-10 sugar units
Glycogen
A carbohydrate made of many glucose molecules linked together in a highly branded structure. It is the storage form of carbohydrate in animals
- stores as liver glycogen and muscle glycogen
- liver glycogen: maintains blood glucose, supplies energy
- muscle glycogen: not used for blood glucose, users in muscle contraction: high intensity exercise and endurance exercise uses muscle glycogen
Starch
A carbohydrate made of many glucose molecules linked in straight or branching chains. The bonds that hold the glucose molecules together can be broken by human digestive enzymes
- plant storage form of CHO
- 300-1000’s of sugar molecules joined together, either linear (amylose) or branched (amylopectin)
Sources of starch:
- carrots, beets, corn and peas
- breads, pastas, cereal
- legumes
Legumes
Plants in the pea or bean family which produce an elongated pod containing large starchy seeds. Include green peas, lentils, kidney beans and peanuts
Dietary fibre
A mixture of indigestible carbohydrates and lignin that is found intact in plants
That slows down nutrient absorption
Functional fibre
Isolated indigestible carbohydrates that have been shown to have beneficial psychological effects in humans
Lactase
An enzyme located in the brush border of the small intestine that breaks the disaccharide last one into glucose and galactose
Lactose intolerance
The inability to digest lactose because of a reduction in the levels of lactase. Is cause symptoms including intestinal gas and bloating after dairy products are consumed. (65% of adults)
- undigested lactose moves to the large intestine
- draws water into large intestine
- bacterial metabolism->acids and has
- bloating, flatulence, cramping and diarrhea
(Lactose->lactase->glucose and galactose)
Resistant starch
Starch that escapes digestion in the small intestine of healthy people
What serves as a food source for the micro flora in the colon
Soluble fibers, resistant starch, prebiotics and oligosaccharides
Glycolysis
Also called anaerobic respiration
Metabolic reactions in the cytosol of the cell that split glucose into 2, 3-carbon pyruvate molecules yielding two ATP molecules
Aerobic metabolism
Metabolism in the presence of oxygen, which can completely break down glucose to yield carbon dioxide, water and as many as 38 ATP
Gluconeogenesis
The synthesis of glucose from simple, noncarbohydrate molecules. Amino acids from protein are the primary source of carbons for glucose synthesis
Occurs in liver and kidney cells
Carbohydrates are also needed for the metabolism of ____
Fat
Ketones
Acidic Molecules formed in the liver when there is not sufficient carbohydrate to completely metabolize the 2-carbon units produced from fat breakdown
- used for energy in some tissues
- can be used in brain for some energy
- sources with starvation, low-carb-diets, diabetes
Plasma
The liquid portion of the blood that remains when the blood cells are removed
Glycemic response
The rate, magnitude, and duration of the rise in blood glucose that occurs after carbohydrates are consumed
Blood-glucose response curve
A curve that illustrates the change in blood glucose that occurs after consuming food
What raises blood glucose more
-low soluble fibre meal or high soluble fibre meal
Low soluble fibre meal has higher up and quick fall
High soluble fibre meal has steady rise and fall
Insulin and glucagon
Hormone secreted by the pancreas in response to a rise in blood glucose levels. Sends out glucose to cells to lower levels.
Hormone secreted by he pancreas in response to a decline in blood glucose levels. Raises glucose levels up.
Diabetes Mellitus
A disease caused by either insufficient insulin production or decreased sensitivity of cells to insulin. Results in elevated blood-glucose levels
Hypoglycaemia
A low blood-glucose level, usually below 2.2-2.8mmol/L of blood plasma
Glycemic index
Ranking of how a food affects the glycemic response
-high glycemic: raises blood sugar lots and quickly
Glycemic load
An index of the glycemic response that occurs after eating specific foods. It is calculated by multiplying a foods glycemic index by the amount of available carbohydrate in a serving of the food
Glycemic load of 20 is high, less than 11 is low
Type 1 diabetes
A form of diabetes that is caused by the autoimmune destruction of insulin-producing cells in the pancreas, usually leading to absolute insulin deficiency; previously known as insulin- dependent diabetes mellitus.
Insulin no longer made by pancreas
Type 2 diabetes
A form of diabetes that is characterized by insulin resistance and relative insulin deficiency; previously known as noninsulin-dependent disbetes mellitus or adult-onset diabetes
Decrease in insulin production
- most common form of 3 types
- usually adults but younger now
Insulin resistance
A situation when tissues become less responsive to insulin and do not take up glucose as readily. As a result, glucose feels in the blood rise
Metabolic syndrome
A collection of health risks, including excess fat in the abdominal region, high blood pressure, elevated blood triglycerides, low high-density lipoprotein cholesterol, and high blood glucose that increases the chance of developing heart disease, stroke and diabetes. The condition is also known as syndrome X, insulin resistance syndrome and dysmetabolic syndrome
Pre-diabetes or impaired glucose tolerance
A fasting blood-glucose level above the normal range but not high enough to be classified as diabetes
Gestational diabetes
A form of diabetes that occurs during pregnancy and resolves after the baby is born
Puts you at greater risk of developing diabetes later in life
Dental Caries
The decay and deterioration of teeth caused by acid produced when bacteria on the teeth metabolize carbohydrate
Hemorrhoids
Swollen veins in the anal and reveal area
Caused by excess pressure in the colon
Diverticula
Diverticulosis
Sacs or pouches that protrude from the wall of the large intestine in the disease diverticulosis. When these get inflamed it’s called diverticulitis
What is the carbohydrate recommendation
45-65% of your kcalories
Sugar alcohols
Sweeteners that are structurally related to sugars but provide less energy than monosaccharides and disaccharides because they are not well absorbed
Xylitol, sorbitol, erythritol
Carbohydrates in the modern diet
The basis of most modern diets
Largest macronutrient consumption
“Whole foods” such as fresh fruit, dairy or whole grains are in their natural state all have carbohydrates
Carbohydrate
- Carbon, hydrogen and oxygen (CHO molecule)
- energy cycles: through photosynthesis, plants combine carbon dioxide, water and the suns energy to form glucose.
- almost exclusively from plants (except for milk-because of milk sugars)
Empty calories
Refers to foods that contribute energy but few other nutrients
-mono and di saccharides
Simple sugars
- Monosaccharides
- fructose
- glucose
- galactose - Disaccharides
- sucrose (glucose and fructose)
- maltose (glucose and glucose)
Only provide body with glucose
-lactose (glucose and galactose)
Refined grains
Corn flakes, puffed rice etc.
- from the endosperm and are mostly starchy
- may be enriched with thiamin, rioboflavin, niacin, and iron and fortified with folate
- do not contain the magnesium, vitamin E, B6, or other nutrients that are lost during processing
Digestion and absorption of CHO
- Salivary amylase (starch->polysaccharides)
- Salivary amylase inactivated when food hits stomach
- Pancreatic amylase (most digestion)
- brush border enzymes
- maltase
- sucrase
- lactase - fibre
Soluble fibre
- dissolves in water
- sources: oats, oat bran, legumes, barley, psyllium, pectin-rich fruits
- types: B-glucan, inulin, mucilage
- benefits for blood cholesterol levels
- reduces cholesterol absorption
Insoluble fibre
- does not dissolve in water
- sources: whole grains, brown rice, bean and bran cereals breads, veggies and fruit
- types: lignin, cellulose
- benefits related to intestinal health: traps water->gives bulk to stool in colon, increases stool weight and volume, lowers intestinal transit time, lowers risk of colon cancer in later life
need to double water intake if you want a fibre supplement work
Following absorption of carbohydrates
- monosaccharides transported to liver
- fructose and galactose are conveyed to glucose
If needed for energy: glucose is released into the bloodstream, where it can travel to cells of the body to produce energy.
If not needed for energy right away: stored as glycogen in our liver and muscles. Liver glycogen used to maintain blood glucose. Muscle glycogen used for energy in muscles.
Aerobic metabolism
Cellular respiration
- glucose is metabolized in the presence of oxygen
- produces ATP
- uses 6 molecules of oxygen to convert one molecule of glucose into 6 molecules of carbon dioxide, 6 molecules of water and 38 molecules of ATP
Protein metabolism when CHO intake is low
- protein can be used for energy if needed
- proteins can be made into ketone bodies (ketogenic) or glucose (gluconeogenesis)
Not desirable
- protein functions are vital
- hormones, enzymes and antibodies
-CHO spares proteins
Best way to break down fat is to also consume
Carbohydrates
If no carbs go through ketones
Ketosis
Increased ketones in blood
Normal and fine to be in for a bit
Ketoacidosis
Is acidic blood from increased ketones
-don’t want acid outside of stomach
Diabetes
- 7.3% of Canadas aged 12*
- blood glucose disease
- elevated glucose caused damage to blood vessels, increasing risk of heart disease and stroke
- leading cause of blindness in adults
- caused renal failure
- major reason for non traumatic lower limb amputations
Rationale for low-carb weight loss diet
- foods higher in carbs stimulate the release of insulin
- insulin promoters energy storage, mostly from fat
- the more insulin you release, the more fat you store
- low-carb diets cause less insulin to be released
- with low-carb diets, the body produces more ketones
- ketones help suppress the appetite
Carbohydrates and heart disease
Diets high in sugar or refined carbohydrates have been shown to raise blood lipid levels and can lead to an increase in heart disease
Diets high in whole grains have been found to reduce the risk of heart disease
-good carbs help manage cholesterol levels
Cholesterol circulates through blood, but with little fibre…. Cholesterol is
Recycled. Cholesterols can not be excreted.
- refined carbs causes circulated cholesterol and gets worse and worse.
- with soluble fibre from veggies and whole grains, cholesterol leaves body with fibre instead of circulating and getting stuck.
Indigestible carbohydrates and bowel disorders
Diets high in fibre or indigestible carbohydrates can relieve or prevent
- haemorrhoids
- diverticulosis
- diverticulitis
- constipation
- colon cancer
Carbohydrate intake
- RDA
- AMDR
- refined carbohydrates
- AI for fibre
RDA: 130g/day for adults and children
-provides the minimum amount of glucose used by the brain
AMDR: 45-65% of energy
- carbohydrates sources should be unrefined
- no more than 25% of carbohydrates consumed should come from added refined sugars
-AI: 38g for young adult men and 25g per day for young adult women
How to calculate %energy from carbohydrate
- determine total kcalories intake for the day
- determine the grand of carbohydrates in the days diet
- calculate energy from carbohydrate
- multiply grams of carbohydrate of 4kcalories per gram
% if energy from carbohydrate = kcalories of carbohydrate/total kcalories x 100
Sugar free
No amount or trivial amount of sugars (less than 0.5g per serving)
Reduced sugar
Lower in sugar
Nutritionally altered product contains 25% less sugar than regular product
Whether altered or not, a food contains 25% less sugar than normal product
No sugars added or without added sugars
No sugar or sugar-containing ingredients is added during processing
Source of fibre meaning
High source of fibre
Very high source of fibre
Food contains at least 2g/serving
Food contains at least 4g/serving
Food contains at least 6g/serving
Non-nutritive sweeteners
- alternative sweeteners
- cyclamate: tabletop sweeteners
- saccharin: tabletop sweetener (pharmacies)
- aspartame: tabletop sweetener, used in uncooked foods
- sucralose- table top sweetener, used in foods, heat stable (Splenda)
- acesulfame K-used in foods, heat stable
- neotame-used in foods, heat stable
- sugar alcohols; chemical derivatives of sugar, listed on the label under carbohydrate, provides less energy than sugar (xylitol, mannitol, sorbitol)
