chapter IV - carbohydrates
A fasting blood glucose of 128 mL/dL suggests that an individual - is healthy - has pre-diabetes - has diabetes
- has diabetes normal: 70 to 99 mL/dL prediabetes: 100 to 125 mL/dL diabetic: 126 mL/dL or higher
a diet rich in complex carbohydrates & fiber
- lower in fat - lower in energy - higher in vitamins & minerals
blood glucose homeostasis
1) when a person eats, blood glucose rises ^ 2) high blood glucose stimulates the pancreas to release insulin into the bloodstream 3) insulin stimulates the uptake of glucose into the cells & storage as glycogen in the liver & muscles insulin also stimulates the conversion of excess glucose into fat for storage 4) as the body's cells use glucose, blood glucose levels decline 5) low blood glucose stimulates the pancreas to release glucagon into the bloodstream 6) glucagon stimulates the liver cells to break down glycogen & release glucose back into the bloodstream 7) blood glucose begins to rise
Read the following article & then answer the questions to decide if there is any validity to the article Awesome & Attractive: The Truth about the Potato Hack 1. True or false? The article provides valid information about the author's expertise, credentials, or title a. True b. False 2. Where did the author find out about the "Potato Hack?" a. Facebook & his buddies in the fitness industry b. Scientific studies he came across while doing resistant start research c. From a registered dietitian creating a personalized diet plan for him d. None of the above 3. Scrolling over the links in the article reveals that the majority of links are to other blogs on the same website, other body-building websites the author likes, & supplements. True or false? a. True b. False 4. Which audience does the author repeatedly say the article is intended for? a. Anyone, because it's health information the masses could benefit from b. Individuals on a carbohydrate restrictive diet due to type II diabetes c. Individuals following the Paleo diet, which restricts processed foods d. None of the above 5. The tendency to search for, interpret, favor, & recall information that confirms one's preexisting beliefs or hypotheses is known as __________________ a. the scientific method b. confirmation bias c. confounding evidence d. due diligence 6. True or False: The "Potato Hack" is eating 2 to 5 pounds of potatoes for several days. On average, 1 pound of potatoes contains 347 calories. The "hack" most likely works as a result of caloric restriction a. True b. False 7. The author states that the "Potato Hack" works because of the resistant starch in potatoes and then mentions a study on resistant starch. The study is neither in the "Potato Hack" nor cited. This is an example of which the following? a. Confounding bias b. Poor quality research c. Non-credible content d. All of the above 8. True or False: Since potatoes are a naturally occurring food, the "potato hack" can't be harmful to anyone a. True b. False 9. True or False: The author suggests that the diet works because of the resistant starch in potatoes & recommends different ways to cook the potatoes. The resistant starch in potatoes is broken down when they are cooked a. True b. False
1. b. False There is no hyperlink to the author's name that provides information about the author's expertise, credentials, or title 2. a. Facebook & his buddies in the fitness industry 3. b. False Linking exclusively, or nearly exclusively, to internal content, comparable content of friends that reinforces the same message, or to products that the author monetizes is a huge red flag of non-credible, biased content 4. c. Individuals following the Paleo diet, which restricts processed foods 5. b. confirmation bias 6. a. True Eating 2 to 5 pounds of potatoes would be between 694 to 1735 calories, below the number of calories needed for weight maintenance in most individuals in the article's intended audience: physically active individuals following a Paleo diet 7. d. All of the above mentioning a study without formally mentioning the name, journal of publication, or any information on the study, not to mention using a graph from the study without proper citation, is confounding bias, poor quality research, non-credible content, & possibly plagiarism 8. b. False The "Potato Hack" could potentially be problematic for diabetics, pregnant women, developing youth, immune-comprised individuals, & other individuals with specific nutrient needs 9. b. False Cooked potatoes, pasta, & rice that have been chilled contain resistant starch
absorption of monosaccharides
1. monosaccharides, the end products of carbohydrate digestion, enter the capillaries of the intestinal villi 2. monosaccharides travel to the liver via the portal vein 3. in the liver, galactose & fructose share metabolic pathways with glucose 4. glucose is used by most cells in the body
type 1 & 2 diabetes
Blood glucose that rises after a meal & remains above normal levels is a characteristic seen in both Type 1 & Type 2 diabetes Type 1 diabetes - less common type of diabetes - the pancreas produces little or no insulin - usually results from autoimmune destruction of pancreatic beta cells type 2 diabetes - more common - cells fail to respond to insulin - occur as a consequence of obesity - best preventive measure is to maintain a healthy body weight Both forms - need to be managed with diet & proper food portions - for some, medications may be necessary to ensure stable blood glucose levels - food portions & choices need to be balanced a common side effect of poorly managed diabetes: hypoglycemia which can be caused by: - too much insulin - strenuous physical activity - inadequate food intake - an illness that may cause blood glucose levels to plummet
general recommended intake of carbohydrates*
CHO = 45-65% of kcals RDA = 130 g/day based upon the average minimum amount of glucose used by the brain FDA uses 60% of 2000 kcal diet on food labels = 300 g/day • 10% or less from concentrate sugar fiber *increase fiber gradually & drink plenty of fluids* • ACS recommends 20-35g daily • This is 2-3 times greater than average • Involves eating more fruit, vegetables, & legumes with less meat diets rich in complex carbohydrates decrease risk of: • Heart disease • Certain cancers • Diabetes • GI disorders
fiber diet recommendations
Fiber & fat slow digestion/absorption of CHOs -> glucose enters blood gradually • Dietary protein elicits glucagon secretion, opposes insulin & helps maintain BS within normal range • ACS recommends 20-35g daily • This is 2-3 times greater than average • Involves eating more fruit, vegetables, & legumes with less meat tips to increase fiber intake: - eat whole grain bread that contains at least 3g of fiber per serving - eat whole grain cereals that contain at least 5g of fiber per serving - eat raw vegetables - eat veggies such as: potatoes & zucchinis with their skins - eat fresh & dried fruit - eat fruits such as: apples & pears with their skins - add legumes to soups, salads, & casseroles
glucose -> glycogen
Glucose for the fuel required by: - brain - nerve cells - developing RBCs • Storage form of glucose primarily in the liver & muscles • Emergency energy reserve of glycogen in the brain after a high CHO meal: - Blood glucose rises & glucose enters cells through the action of insulin - Glycogenesis-In the liver excess glucose molecules link through condensation reaction to form glycogen when blood glucose falls: Glycogenolysis - Liver breaks down glycogen -> glucose through hydrolysis reactions
weight & obesity in regards to carbohydrates
Obesity & the link to carbohydrates? • Total daily energy intakes have increased • Activity levels have declined • Increase in body weight ^ weight loss --> kCalorie intake Increase in consumption of added sugars • High-fructose corn syrup • Body fat stores carbohydrate cravings • Self-imposed labeling of foods as good or bad • Carbohydrate "addiction" -> not physiological or pharmacological
dieting methods for diabetes
Plate Method • basic Exchange lists • Highly structured • May not be highly accepted Carb counting • Flexible • Offers variety • 1 serving = 15g CHO • Or one fruit, starch, milk, & vegetables (large portions)
Select whether each carbohydrate is a monosaccharide, disaccharide, or polysaccharide
The suffix -saccharide means "sugar" - all carbohydrate molecules are composed of sugars Mono - means "one," so a monosaccharide is a single sugar molecule or a simple carbohydrate - Monosaccharides are the building blocks for larger, more complex carbohydrates - Fructose, galactose, & glucose are monosaccharides Di - means "two," so a disaccharide is a sugar molecule composed of two monosaccharides - These are also known as simple carbohydrates because they are easily digested & affect blood sugar levels similarly - Lactose is a disaccharide comprised of glucose & galactose - Maltose is a disaccharide comprised of two glucose molecules - Sucrose is a disaccharide comprised of glucose & fructose Poly - means "many." Polysaccharides, or complex carbohydrates, are composed of many monosaccharides (hundreds or thousands) - However, many organisms need to break down polysaccharides into monosaccharides before entering the bloodstream - Starch, fibers, & glycogen are polysaccharides
epinephrine
a "fight or flight" hormone secreted by the adrenal gland that elicits a release of glucose storage in the liver in times of stress • gives a burst of energy
carbohydrates
a compound composed of sugars primary role: to supply energy by conversion to glucose "blood sugar" *your brain will only use glucose* simple - monosaccharides & disaccharides complex - polysaccharides chemical view: molecules containing 6 carbon atoms, 12 hydrogens, & 6 oxygens ultimate goal: to render all available CHO into small compounds the body can use
Phenylketonuria (PKU)
a disorder related to a defective recessive gene on chromosome 12 that prevents metabolism of phenylalanine *aspartame can effect patients with this disease*
splenda (sucralose)
a molecule of sugar with chloride atoms attached 23 packs approved
starch
a polysaccharide that serves as a storage form of glucose in plants major food energy source worldwide: - grains - root crops & tubers - legumes long branched (amylopectin) or unbranched (amylose) chains of hundreds of thousands of glucose molecules
galactose
a simple sugar that is seldom free in nature as it bonds with glucose to form lactose
glycogen
a storage form of glucose in animals made & stored in: liver & muscle more complex & branched than starch - each new glycogen molecule needs a special protein for the attachment of the first glucose *enzymes can attack all branches simultaneously - occurring through a condensation reaction*
high-fructose corn syrup is composed of fructose & glucose in an approximate ratio of _____ a. 50:50 b. 75:25 c. 25:75 d. 40:60
a. 50:50 High-fructose corn syrup is composed of fructose & glucose in an approximate ratio of 50:50
Research studies suggest that a high-fiber diet protects against which of the following? a. Colon cancer b. Gluten intolerance c. Heartburn d. Acid reflux
a. Colon cancer Research studies suggest that a high-fiber diet protects against colon cancer
Fructose & galactose are mostly metabolized in which of the following organs? a. Liver b. Gallbladder c. Small intestine d. Stomach
a. Liver In the liver, galactose & fructose share metabolic pathways with glucose
Low blood glucose stimulates which of the following organs to release glucagon into the bloodstream? a. Pancreas b. Liver c. Gallbladder d. Kidneys
a. Pancreas when blood glucose falls, special cells of the pancreas respond by secreting glucagon into the blood
Which is a function of glucagon? a. The breakdown of glycogen from the liver b. The uptake of glucose from the blood into cells c. The storage of glycogen in the liver & muscles d. The conversion of excess glucose into fat for storage
a. The breakdown of glycogen from the liver
a healthy body needs & uses glucose as its primary energy source a. true b. false
a. true glucose fuels the work of most of the body's cells and is the preferred energy source for brain cells, other nerve cells, and developing red blood cells.
The Daily Value for fiber on food labels is 28 grams a. true b. false
a. true The Daily Value for fiber on food labels is set at 28 grams for a 2000-kcalorie intake
about 15 percent of the average daily energy intake comes from concentrated sugars that have been refined & added to foods a. true b. false
a. true about 15 percent of the average daily energy intake of sugars comes from the concentrated sugars that have been refined & added to foods
If healthy adults choose their food wisely, they can usually obtain all the needed nutrients while consuming about 1500 kcalories per day a. true b. false
a. true by following one of the USDA Food Patterns & making careful food selections, a typical adult can obtain all the nutrients needed with a daily allowance of about 1500 kcalories
the activity of the above enzyme diminishes in the stomach due to stomach -----
acidity
type I diabetes
an autoimmune disorder characterized by lack of insulin production by the beta cells of the pancreas • juvenile onset • less common • pancreas unable to synthesize insulin • injection of insulin needed for cells to take up blood sugar -cannot take orally • called insulin-dependent diabetes mellitus (IDDM) diet: • diet, exercise, & insulin • carbohydrate counting • provide even amounts of carbohydrates throughout the day
saccharin
artificially sweet - was removed from list of "cancer-causing substances" in 2000
Rosa is supposed to consume 45 grams of carbohydrates at each meal Which meal is appropriate for her? a. A cup of cottage cheese & an orange b. A turkey & cheese sandwich with an apple c. A cup of green beans & four ounces of turkey d. A ½ cup of mashed potatoes & three ounces of roast beef
b. A turkey & cheese sandwich with an apple
which of the following foods ranks low on the glycemic index? a. White rice b. Barley c. Watermelon d. Sweet potato
b. Barley barley is a food that is low on the glycemic index of common foods
dietary fiber is found in good amounts in all of the following foods EXCEPT: a. Apple b. Chicken breasts c. Beans d. Carrots
b. Chicken breasts protein foods deliver almost no carbohydrates to the diet, except nuts & legumes
which of the following compounds is produced by the liver during the breakdown of fat when carbohydrate is not available? a. Insulin b. Ketone bodies c. Beta cells d. Glucagon
b. Ketone bodies Ketone bodies are acidic compounds produced by the liver during the breakdown of fat when carbohydrate is not available
Which of the following sugars is NOT found in plant foods? a. Glucose b. Lactose c. Fructose d. Sucrose e. Maltose
b. Lactose Lactose is found in milk and milk products from animals, not from plants.
which food contains resistant starch, which escapes digestion & absorption? a. Milk b. Legumes c. Applesauce d. Very ripe banana
b. Legumes
The warning label that appears on products containing aspartame is necessary to prevent problems for people with the following conditions? a. Fat absorption b. Phenylketonuria c. Diabetes d. Cardiac disease
b. Phenylketonuria Products containing aspartame must carry a warning for people with phenylketonuria
The action of bacterial enzymes on fiber in the large intestine results in which of the following reactions? a. Release of acid secretions b. Release of short-chain fatty acids c. Delay of gastric emptying d. Release of small amounts of polysaccharides
b. Release of short-chain fatty acids Bacteria in the gastrointestinal (GI) tract ferment some fibers, which generate water, gas, & short-chain fatty acids
most lactose-intolerant people cannot consume any products that might contain lactose a. true b. false
b. false managing lactose intolerance requires some dietary changes, although the total elimination of milk products is usually unnecessary. Most lactose-intolerant individuals need to manage their dairy consumption rather than eliminate it
Glycogenolysis
breakdown of glycogen into glucose
hydrolysis
breaks a disaccharide in two - uses H20 *during the digestion process, CHOs are broken down into smaller units*
How is glycogen typically stored in the body? a. Half in the liver & half in the muscle cells b. Three-fourths in muscle tissue & one-fourth in brain tissue c. One-fourth in the liver & three-fourths in the muscle cells d. Half in the muscle cells, one-fourth in the peripheral tissues, & one-fourth in the stomach
c. One-fourth in the liver & three-fourths in the muscle cells
Which sugar is a disaccharide? a. Glucose b. Fructose c. Sucrose d. Galactose
c. Sucrose
big takeaways
carbohydrate digestion & absorption In the digestion & absorption of carbohydrates, the body breaks down starches into disaccharides & monosaccharides, which are absorbed fiber The fibers contribute little, if any, energy, but help regulates the passage of food through the GI tract & slow the absorption of glucose Lactose intolerance relatively common condition that occurs when a person's body produces insufficient lactase to digest the disaccharide lactose found in milk & milk products. Symptoms are limited to GI distress. Because treatment requires limiting milk & milk products in the diet, alternative sources of calcium, potassium, & vitamin D must be included. Sugars increase the risk of dental caries; excessive intakes displace needed nutrients & fiber & contribute to weight gain when energy intakes exceed needs. Consumers are advised to limit their intake of added sugars to less than 10 percent of their daily energy intake. Alternative sweeteners may help limit kcalorie & sugar intakes.
hypoglycemia (low blood glucose)
causes: - too little food - too much insulin or diabetes medicine - extra activity onset: - sudden - may progress to insulin shock symptoms: - shaking - fast heartbeat - sweating - dizziness - anxious - hunger - impaired vision - weakness/ fatigue - headache - irritable what can you do: - drink 1/2 glass of juice - 1/2 glass regular soft drink - 1 glass of milk - eat some soft candies (not chocolate) within 20 min after treatment TEST BLOOD GLUCOSE - if symptoms don't stop, call your doctor then eat a light snack: - 1/2 peanut butter - meat sandwich with 1/2 glass of milk
hyperglycemia (high blood glucose)
causes: - too much food - too little insulin or diabetes medicine - illness or stress onset: - gradual - may progress to diabetic coma symptoms: - extreme thirst - frequent urination - dry skin - hunger - blurred vision - drowsiness - nausea what can you do: - test blood glucose test ketones - call your doctor if your blood sugar level is over 250 mg/dL
phytates
compounds present in plant foods (particularly whole grains) that bind & may prevent absorption of some minerals found in: - husks of grains - legumes - seeds bind to minerals: Zn, Fe, Ca, Mg, Cu
carbohydrate metabolism
converts fructose & galactose -> glucose storing glucose as glycogen liver storage • condensation into glycogen • hydrolysis for release of glucose when needed • 1/4 of the total storage of glycogen muscle storage • selfishly hoards glycogen • 3/4 of the total storage of glycogen glucose for energy • fuels most of the body's cells • preferred source for the brain, nerve cells, & developing red blood cells • cellular breakdown of glucose gluconeogenesis • making glucose from protein • amino acid conversion
Glyconeogenesis
creating glucose from substances such as amino acids & glycerol -carried out in the liver
a person with prediabetes has a fasting blood glucose level of _____ milligrams per deciliter a. 70-100 b. <70 c. 126-150 d. 100-125
d. 100-125 The prediabetes blood glucose levels are 100-125 milligrams per deciliter
a typical serving of fruit, such as an apple or an orange, contains an average of about _____ a. 6 grams of carbohydrates b. 20 grams of carbohydrates c. 30 grams of carbohydrates d. 15 grams of carbohydrates
d. 15 grams of carbohydrates
Now, choose the individual who is most likely to have type 2 diabetes: a. 40-year-old runner who smokes b. teenage girl whose mother has diabetes c. 6-year-old child d. 62-year-old inactive man
d. 62-year-old inactive man type 1 diabetes - beta cells are killed by an immune reaction -> as a result, the remaining beta cells are unable to secrete enough insulin to drive cellular uptake of glucose & remove it from the blood type 2 diabetes - beta cells secrete insulin, but the target cells of the body fail to respond to insulin & absorb the glucose from the blood - In later stages, the pancreas begins to fail - often referred to as adult-onset diabetes because it is often the result of lifestyle factors such as: - poor diet - physical inactivity that take years to accumulate, Therefore, you see a much higher incidence of type 2 diabetes in older populations
Total fiber refers to the sum of which of the following? a. Functional & viscous fibers b. Dietary & viscous fibers c. Starch & cellulose d. Dietary & functional fibers
d. Dietary & functional fibers Total fiber refers to the sum of dietary & functional fibers
People on strict lactose-free diets need to read labels & avoid foods with all of the following ingredients EXCEPT: a. Milk b. Milk solids c. Whey d. Gluten
d. Gluten people on strict lactose-free diets need to read labels & avoid foods that include milk, milk solids, whey, & casein
storage forms of glucose in living things include which of the following? a. Maltose & sucrose b. Phytates & viscous fibers c. Fibers & disaccharides d. Glycogen & starch
d. Glycogen & starch The human body stores glucose as glycogen & plants store glucose as starch
Which statement is true of sugar alcohols? a. They can cause constipation b. They contribute to dental caries c. They don't occur naturally in any food d. They provide 0.2 to 2.6 kcals per gram
d. They provide 0.2 to 2.6 kcals per gram
Which food contains the type of fiber that benefits GI health? a. Oats b. Carrots c. Psyllium d. Wheat bran
d. Wheat bran
if fiber is present in the stomach it ----- gastric emptying
delays
dietary fiber coca-cola vs broccoli
dietary fiber is also an important consideration when discussing the impact of carbohydrate sources on blood sugar levels. In this example, soda is a poor source of fiber, & broccoli is a good source of fiber Dietary fiber is found mostly in carbohydrate sources that include fruits, vegetables, whole grains, & legumes. Fibers include the indigestible components of plant foods & are commonly classified as soluble & insoluble. A high-fiber diet has a variety of benefits that include maintaining bowel health, lowering cholesterol levels, & lowering blood sugar levels
starch vs. cellulose
differ in the connection between glucose units & the amount of branching in the molecule starches: coiled or branched cellulose: long, unbranched chains held together by hydrogen bonds
available carbohydrates
digestible by human enzymes & able to be used
diabetes
disorder of blood glucose regulation symptom: hyperglycemia - high blood sugar type I • juvenile onset • less common • pancreas unable to synthesize insulin • injection of insulin needed for cells to take up blood sugar -cannot take orally • called insulin-dependent diabetes mellitus (IDDM) type II • most common form • adult onset- old name • cells are resistant to insulin • obesity is a major factor • increased risk with age as pancreas function decreases effects of diabetes • chronic high blood sugar alters glucose metabolism in almost every cell of the body • diseases of the blood vessels & nerves • 80% of people with diabetes die as a result of CV disease • impaired circulation - strokes & heart attacks • impaired vision • loss of sensation of limbs • infections - bacteria feed on glucose-rich blood • cannot be detected due to decreased sensation
All of the following statements are true about carbohydrates except: a. All carbohydrates are made up of monosaccharides b. Simple carbohydrates include sugars c. Plants are the major source of carbohydrates in our diet d. A diet containing too much simple sugar can be harmful to one's health e. Complex carbohydrates include starch, fruit juice, & fiber
e. Complex carbohydrates include starch, fruit juice, & fiber Complex carbohydrates include starch & fiber, but not fruit juice, which is made up of simple sugars
Which of the following statements is NOT true about carbohydrate structures? a. Simple carbohydrates include monosaccharides & disaccharides b. Lactose is a disaccharide composed of glucose linked to galactose c. Complex carbohydrates are polysaccharides consisting of many glucose units joined together d. Maltose is a disaccharide composed of glucose linked to glucose e. Sucrose is a disaccharide composed of glucose linked to galactose
e. Sucrose is a disaccharide composed of glucose linked to galactose Sucrose is a disaccharide composed of glucose linked to fructose, not galactose
glycemic effect of food
extent to which a food raises blood glucose concentration & elicits an insulin response depends on: • digestibility of starch • interaction of starch & protein • amount & kinds of fat, sugar, & fiber • other constituents that may bind starch • consistency of the food • combination of foods eaten at one time • is important for imbalances, but cannot predict responses in mixed meals • best way is to control total energy intake
viscous (soluble) fibers
fiber that dissolves in water to form a gel helps with: - heart disease - diabetes - weight control function: • control blood lipids & CVD • decrease cholesterol - binds bile acids • decrease the rate of glucose absorption ex. diabetes • delays gastric emptying • can treat diarrhea • fermentable fibers are fermented /digested by bacteria in the colon • used to thicken jellies ex. pectin - used to thicken jelly & keep salad dressing from separating found in: - fruit - oats - barley - legumes
herbal product (sugar)
generally recognized as safe (GRAS) ex. stevia
sucrose
glucose + fructose table sugar occurs naturally in fruit
lactose
glucose + galactose 30-50% of milk energy
maltose
glucose + glucose malt sugar - used in the germination of seeds & barley
what is the richest food source?
grains
insulin
hormone that acts to take glucose out of the blood & deposit it into cells
glucagon
hormone that brings glucose out of storage form in the liver
broccoli
is an example of a complex carbohydrate that will increase blood sugar levels slowly because it is comprised of polysaccharides Complex carbohydrates are much larger molecules comprised of hundreds to thousands of monosaccharides. Since organisms need to break polysaccharides down into monosaccharides before they can enter the bloodstream, digestion and absorption are much slower, which delays the entry of sugar into the blood
Coca-Cola
is an example of a simple carbohydrate that will increase blood sugar levels quickly because it is comprised of monosaccharides Simple carbohydrates are comprised of one or two sugar molecules. Because of this, they are digested & absorbed rapidly, thus entering the bloodstream & increasing blood sugar levels quickly. Foods that contain many simple sugars are generally those devoid of complex molecules, such as fiber or starch
condensation
links 2 monosaccharides together - releases H20
sugars
moderate intake recommended • 5-10% of total energy intake neutral to health except in excess - contributes empty calories (a person will consume ~ 100lbs of sugar per year) • may displace fiber & nutrients • causes dental cavities discussion around sugar: 1) Unnatural; not a nutrient; an additive; dangerous 2) Causes malnutrition 3) Causes obesity (can contribute) 4) Cause Diabetes 5) Causes hyperlipidemia 6) Cause hyperactivity *sugar is not the cause but can contribute when in excess & combined with other medical issues or habits*
simple carbohydrates
monosaccharides & disaccharides
type II diabetes
most common form • adult onset- old name • cells are resistant to insulin • obesity is a major factor • increased risk with age as pancreas function decreases diet: • weight control • provide even amounts of carbohydrates throughout the day • carbohydrate counting - flexible - offers variety - 1 serving = 15g CHO - Or one fruit, starch, milk, & vegetables (large portions) • fat intake - decrease unless monounsaturated fats
carb digestion starts in the ---- the salivary enzyme ---- works to bgein starch digestion
mouth amylaze
Aspartame (Nutrasweet)
nonnutrative sweetner that is 160-200 times sweeter than sucrose 1981 FDA Approval in dry goods comes in: - liquid - granular - encapsulated - powder forms no known long-term health effects except for certain subgroups.....warning for PKU
carb counting
normal recommendation: 45-60g per meal grains - 1 piece of bread, or 1⁄2 c pasta or rice • ~15 grams of carbohydrate vegetables important to note starchy/non-starchy starchy - corn, peas, & potatoes have a higher starch content 1⁄2 cup is ~ 15 g CHO non-starchy veg- - broccoli - carrots - green beans 1⁄2 cup cooked or 1 cup raw is ~ 5g CHO fruits - 1 small fruit ex. peach or 1⁄2 cup is ~ 15 grams of CHO milk & milk products 1c is ~ 12g CHO protein foods 0 CHO fats/oils 0 CHO
chemical structure of glucose
on paper, the structure of glucose has to be drawn flat, but in nature, the five carbons & oxygen are roughly in a plane. the atoms attached to the ring carbons extend above & below the plane.
dietary fibers
plant material that remains after food passage through the GI tract - that cannot be digested kinds of dietary fibers: - viscous (soluble) - insoluble • rapid increase may cause discomfort • increase water intake along with increased fiber • too much is not better than too little • fiber in foods preferable to supplements
complex carbohydrates
polysaccharides - composed mainly of glucose units - should contribute to 45-60% of caloric intake types: - starch - glycogen
sugar alcohols (polyols)
provide half as much energy as sucrose, but not as sweet - may cause diarrhea if allowed to sit unabsorbed in the intestines for an extended time as it draws water Benefit: does not contribute to dental cavities Used in chewing gum ex. sorbitol, mannitol, xylitol
dextrins
short chains of glucose units resulting from starch breakdown *used to thicken foods*
monosaccharides
simple carbohydrate molecules: - glucose - fructose - galactose
disaccharides
simple carbohydrates that are made up of two monosaccharides - sucrose - lactose - maltose
carbohydrate digestion
starts in the mouth - amylase converting polysaccharides -> disaccharides small intestine 1) pancreatic amylase 2) specific disaccharide enzymes convert disaccharides to monosaccharides: - sucrase - maltase - lactase *glucose & fructose are handled essentially the same way in the body -> honey & sugar both have glucose & fructose* large intestine - fibers
nonnutritive sweeteners
sugar substitutes don't provide energy (calories) large does can lead to adverse effects ex. aspartame, splenda, & saccharin
glucose
the form of sugar that circulates in the blood & provides the major source of energy for body tissues when its level is low, we feel hunger it is not very sweet also called: dextrose
lactose intolerance
the inability to digest lactose due to lack of the enzyme lactase • may be inherited or acquired • lack of lactase enzyme can be due to intestinal villi damage caused by: - disease - malnutrition - medications - prolonged diarrhea lactose molecules remain in the intestine attracting H2O & feeding bacteria causing acid & gas symptoms: - gas - pain or cramps in the lower belly - gurgling sounds - loose stools - diarrhea - bloating treatment: • lactose-free diet - total elimination is usually unnecessary avoid: - milk - milk solids - whey - casein • lactose-restricted diet - eat small amounts at one time (6 g lactose/meal = 1⁄2 c. milk) • lact-aid milk - lact-aid tablets - soy milk *monitor calcium intake as it may be lost with using milk alternatives as milk products contribute Ca, vitamin D, & riboflavin* • drink with other foods • eat fermented products - Kefir - yogurt • eat cheese - most of the lactose removed with whey • Enzyme added or use drops *not the same as milk allergy which is an immune response to the protein in milk*
metabolic consequences of untreated diabetes
the metabolic consequences of type 1 diabetes are more immediate & severe than those of type 2 - in type 1, no insulin is available to allow any glucose to enter the cells --> when glucose cannot enter the cells, a cascade of metabolic changes follows - in type 2 diabetes, some glucose enters the cells --> because the cells are not "starved" for glucose, the body does not shift into the metabolism of fasting (losing weight & producing ketones)
fiber
the structural part of plants found in: - whole grains - vegetables - fruit - legumes how is fiber different from starch? • they are polysaccharides that are not digested by human digestive enzymes • bonds between glucose units are unable to be broken energy contribution is negligible examples of fibers: - cellulose - hemicellulose - pectins - gums - mucilages - lignins
fructose
the sweetest natural sugar, found in fruits & vegetables in a pentagon shape also called: - levulose - fruit sugar
insoluble fibers
the tough indigestible food components that do not dissolve in water helps with: GI health function: • decrease transit time in the small intestine • must be used moderately by people with marginal intakes prevention of: - colon cancer - appendicitis - diverticulitis - hemorrhoids found in: tough fibers - bran fiber - vegetables - wheat - grains
characteristic of diabetes: disease onset may be triggered by a virus
type 1
characteristic of diabetes: Glucose levels remain above normal after a meal
type 1 & 2
characteristic of diabetes: Poor diet can result in low blood sugar
type 1 & 2
characteristic of diabetes: Insulin made is ineffective
type 2
characteristic of diabetes: Weight gain increases risk
type 2
characteristic of diabetes: obesity increases risk
type 2
constancy of blood glucose
• optimal at 80-100 mg/dL • hunger occurs at 60-65 mg/dL The pancreas responds to changes in levels of blood glucose if glucose levels are high ^ beta cells in the pancreas secrete insulin • most cells take enough glucose for immediate energy needs If glucose levels are low - alpha cells secrete glucagon - epinephrine secreted by the adrenal gland muscles & liver take extra glucose & store long chains in the form of glycogen • muscle glycogenesis used primarily within the muscle - Glycogen can be converted back to glucose • liver can convert excess glucose to fat for export & storage in fat cells - cannot covert back to glucose *the brain & Nervous systems use Glucose as an exclusive fuel source*
