Chapter 5: Carbohydrates
Pregnant women who have a_______________ are more likely to have gestational diabetes than pregnant women who dont have these characteristics.
family history of type 2 diabetes, are overweight, or have high blood pressure
People who are sensitive to aspartame have complained of ___________ but no scientific evidence have linked these problems to aspartame.
headaches, cancer, immune system diseases
Insulin
helps regulate blood glucose levels b/c the hormone enables glucose to enter most cells
Food manufacturers use large amts. of ___________ as a food additive to satisfy Americans' demand for "regular" soft drinks, candies, baked goods
high fructose corn syrup (HFCS)
Most cases of type 1 diabetes begin with an _______ system disorder, which causes destruction of the __________- producing cells in the _________.
immune; insulin; pancreas
What individuals are more likely to develop type 2 diabetes
individuals who're physically inactive, have excess body fat, are genetically related to a close family member w/ type 2; americans who have hispanic, native am., asian, african, or pacific islander ancestry
In the early 1970s, a group of scientists noted that rural African populations who typically ate high-fiber diets rarely developed colorectal cancer. When these populations moved to urban areas and adopted relatively low-fiber Western diets, their risk of colorectal cancer increased. As a result of these observations, the scientists suggested that high-fiber diets were protective against colorectal cancer. Today, scientists think a healthy diet that supplies high-fiber foods, such as whole grains, fruits, and vegetables, may reduce the risk of colorectal cancer.
be familiar w/ this
Glycogenolysis
breakdown of glycogen into glucose; releases glucose into bloodstream
Lipolysis
breakdown of triglyceride (fat) into glycerol & fatty acids. as a result glycerol & fatty acids rapidly enter the bloodstream
What are food sources of unprocessed carbohydrates
brown rice, baked potato, apples, tomatoes, milk
The FDA has also approved the use of ______________ from leaves of the stevia plant.
commercially purified extracts (steviol glycosides)
Disaccharide
composed of 2 monosaccharides
Which of the following alternative sweeteners was once believed to cause bladder cancer but since has been proven safe? a. neotame b. cyclamate c. sucralose d. sorbitol
cyclamate
The pancreas contains beta cells, clusters of special cells that produce _________, and groups of alpha cells that produce _______. These 2 hormones play key roles in regulating blood glucose levels.
insulin; glucagon
The ________ is the main site for CHO digestion & absorption, but a minor amount of starch digestion begins in the mouth, as ___________ converts some of the starch molecules into maltose.
small intestine; salivary amylase
Alternative nutritive sweeteners include sugar alcohols: _________, ________, & ________.
sorbitol, xylitol, mannitol
Plants store glucose as ________, primarily in the form of amylopectin, in their seeds, roots, & fleshy underground stems called __________.
starch; tubers
Glucagon _________
stimulates liver & kidney cells to produce glucose from certain amino acids; stimulates lipolysis as well
Salivary amylase does not function in an acid environment. Thus, starch digestion stops soon after food enters the __________ because that is where salivary amylase is inactivated.
stomach
What is the carbohydrate that all other sweeteners are benchmarked (compared) against?
sucrose
Identify names of sugars that may be found in foods
sugar, honey, molasses, raw sugar, lactose, maltodextrin, NOT glycogen
What foods contain large amounts of refined CHO, including added sugars
sugar- sweetened beverages, cookies, chips, many other snack foods
Both sugar & sugar alcohols provide _________
sweetness
Sucrose
table sugar; consists of 1 molecule of glucose + 1 of fructose - occurs naturally in honey, maple syrup, carrots, pineapples; however, much of the sucrose in Am. diet is refined from sugar cane & sugar beets
The _____ uses cholesterol to make bile. The ________ stores bile & releases it into the small intestine during meals.
liver; gallbladder
Amylose
long straight chain of glucose units
A serving of high fiber food generally has (higher/lower) energy content than the same volume of a low fiber food.
lower
Maltose
malt sugar; has 2 glucose molecules bonded together; few foods naturally contain maltose
The enzyme ________ digests maltose into glucose molecules.
maltase
Disaccharides include:
maltose, sucrose, lactose
_________ & __________ are often excellent sources of protein, many vitamins, and the minerals calcium & phosphorus
milk & milk products
Sugars are ___________ because they are carbohydrates that contribute energy to foods.
nutritive sweeteners
Diets high in fiber can lower the risk of developing:
obesity, diabetes, heart disease
In the small intestine, an amylase secreted by the Pancreas (______________) breaks down the remaining polysaccharides in starch into maltose molecules.
pancreatic amylase
Sugar also serves as a ____________ by inhibiting the growth of molds & bacteria that would otherwise cause food spoilage.
preservative
Reactive hypoglycemia
refers to low blood sugar that occurs after a meal containing high amts. of refined carbs
Metabolic Syndrome
(condition characterized by 3+ of these signs) - large waist circumference - chronically elevated BP (hypertension) - chronically elevated fasting blood fats (triglycerides) - low fasting high density lipoprotein cholesterol (HDL cholesterol) - high fasting blood glucose
Sucralose
- Splenda; made from a molecule of sucrose thats been chemically modified to escape digestion & absorption; as a result, it sweetens things w/o increasing the caloric value - 600x sweeter than sucrose - excreted in feces unchanged - under normal cooking conditions, not destroyed by heat (making it better for baked products)
Each gram of a mono- or disaccharide supplies _____ kcals.
4
Nutritionally, adequate diets should provide ______ to ______% of total energy from carbs.
45-65%
Diabetics should try to keep their hemoglobin A1c levels below ____%.
7%
As your blood glucose level begins to rise after a meal, how does your pancreas respond
responds by secreting insulin into the bloodstream
The Food and Drug Administration has approved the use of 6 high- intensity sweeteners:
saccharin, aspartame, acesulfame-K, sucralose, neotame, & Advantame
Type 2 Diabetes
Beta cells of people with type 2 diabetes usually produce insulin, but the hormone's target cells are insulin-resistant, which means they do not respond properly to the hormone and do not allow glucose to enter them
What cells can ONLY use glucose as a fuel
CNS & RBCs
How does metabolism play a major role in the development of obesity
- when a person consumes excess carbs, their body converts some of the glucose into fat, but much of the excess is "burned" as biological fuel - as a result, dietary fat is spared from being used as a fuel & stored in fat cells; thus, eating too much CHO indirectly contributes to excess body fat
Americans typically consume about ____tsp of added sugars per day
22tsp
What percent of Americans 65+ years or older have diabetes?
25%
What happens to the final products, glucose molecules, of starch digestion?
absorbed into intestinal bloodstream & transported to the liver via hepatic portal vein. nearly all starch is digested. complex carbs that remain are primarily forms of fiber
Honey contains what type of spores that can be deadly to young children?
clostridium botulinum
Dietary Fiber (fiber)
- complex carbohydrates composed of monosaccharides; monosaccharides are connected to each other by bonds that humans cant digest - it can be metabolized (fermented) by gut microbiota); any fiber not used by microbes contributes to stools that are later eliminated during bowel movements - 2 types: soluble & insoluble fiber
Nonnutritive Sweeteners
- (sugar replacers/ substitutes, artificial sweeteners) - substances added to food that sweeten the item while providing few or no kilocalories
Amylopectin
- a highly branched chain of glucose units
The brain's primary source of fuel is:
simple sugars
Complex Carbohydrates (polysaccharides)
- comprised of 10+ monosaccharides bonded together - plants & animals use them to store energy or make certain structural components like stems & leaves
Ketosis
- condition that occurs when ketone bodies accumulate in the blood - low carb diets lead to a condition which can disturb the body's normal acid- base balance and is called ketosis
Hypoglycemia
- condition that occurs when the blood glucose level is too low too provide energy for cells - blood glucose level is less than 70 mg/dl
Ketoacidosis
- condition that occurs when the body forms excessive ketones - if not treated, can result in loss of consciousness (coma) & death - signs/ symptoms: excessive thirst, frequent urination, blood glucose level of more than 250 mg/dl; nausea, vomiting, fatigue, confusion; "fruity" or acetone (chemical in nail polish remover) odor breath
How does starvation effect the body
- dramatically alters the body's energy metabolism - starvation diets lack sources of energy like glucose & AA, but the body needs glucose to fuel vital activities like breathing, transmitting nerve impulses, pumping blood
Pre-diabetes (impaired glucose tolerance)
- fasting blood glucose levels that are 100-125 mg/dl - person has a high risk of CV disease & eventually developing type 2 diabetes
Fructose
- fruit sugar or levulose - sweeter than glucose; easily made from corn - found in fruit, honey, a few vegetables, particularly cabbage, green beans, asparagus - body has little need for this, but it can convert the monosaccharide to fat or glucose
The most common dietary polysaccharides consist of hundreds of _________________ and include _______&________ forms.
- glucose molecules - digestible & non-digestible forms
Diabetes mellitus (diabetes)
- group of serious chronic diseases characterized by abnormal glucose, fat, and protein metabolism; type 1 & type 2 - fasting blood glucose levels of 126 mg/dl or more
Galactose
- not commonly found in foods - a component of lactose, the form of carbohydrate in milk - ex: after a woman gives birth, special glands in her breasts convert glucose to galactose, which is necessary for production of lactose
Starch & Glyogen
- polysaccharides that contain hundreds of glucose molecules bound together into large chainlike structures
Hyperglycemia
- primary sign of diabetes; abnormally elevated blood glucose levels - 2 reasons why people w/ diabetes may experience this: (1) b/c their beta cells dont produce any insulin or just not enough to meet their needs OR (2) the affected person produces some insulin but their body doesnt respond properly to the hormone (insulin resistance) - major signs/ symptoms: excessive thirst, frequent urination, blurred vision, poor wound healing - over time, it damages nerves, organs, blood vessels
Sugar Alcohols
- sorbitol, xylitol, mannitol - unlike sugars, they do not promote dental decay - thus, these compounds are used to replace sucrose in products such as sugar free chewing gums, breath mints, "diabetic candies" - may cause diarrhea when consumed
The glycemic index of a food can vary depending on:
- the extent of processing - its degree of ripeness - where the food was grown
T/F: Dietary fiber includes indigestible plant and animal material.
false
Monosaccharides
simplest sugar; basic chemical unit of carbohydrates
High- Intensity Sweeteners
- a group of nonnutritive sweeteners that have an extremely sweet taste when compared to the same amt. of table sugar. thus a very small amt. of it is needed to sweeten a food - supply little or no energy per serving
Glucose
- also called dextrose; may be referred to as blood sugar - most important monosaccharide in human body b/c its the primary fuel for muscle & other cells - good sources include: fruits & veggies, especially berries, grapes, corn, carrots
Tooth decay
- associated w/ consuming certain CHO, particularly simple sugars that stick to teeth - w/o good dental hygiene practices, the debris becomes food for bacteria that live on teeth; as bacteria metabolize CHO for their energy needs, the acid they produce damages tooth enamel & results in decay
Rich food sources of starch include:
- bread & cereal products made from wheat, rice, barley, oats - veggies: corn, squash, beans, peas - tubers: such as potatoes, yams, taro, cassava, jicama
According to food labeling guidelines issued by the FDA, whole grains are the intact, ground, cracked, or flaked seeds of ___________. Such grains include:
- cereal grains - wheat, buckwheat, oats, corn, rice, wild rice, rye, barley, bulgar, millet, sorghum
Hemoorhoids
- clusters of small rectal veins that can become swollen & inflamed, making them likely to bleed & cause discomfort & itching - commonly affects adults & may be more likely to occur when one sits for long periods or strains during bowel movements
lactose intolerance (lactose maldigestion or malabsorption)
- inability to digest lactose completely; affects millions of americans - people do not produce enough lactase (enzyme that breaks lactose into glucose and galactose). When they consume lactose, the disaccharide is not completely digested and absorbed by the time it enters the large intestine. Bacteria in the large intestine break down lactose and produce irritating gases and acids as metabolic by-products - symptoms: intestinal cramps, bloating, gas, diarrhea w/i 30mins to 2 hrs after consumption
Consequences of eating too much fiber
- may interfere w/ small intestines ability to absorb certain minerals - in rare instances, it could result in intestinal blockage, esp. if fluid intake is low
Benefits of eating high fiber foods
- may reduce risk of obesity, diabetes, certain intestinal tract disorders, CVD- which includes heart disease & stroke - softer stools, more regular bowel movements, less likely to strain while having bowel movements
What is the Adequate Intake level (AI) of fiber for young men? for young women?
- men: 38g/ day - women: 25 g/day
Type 1 Diabetes
- more likely to occur in children & young adults; but disease can still hit @ any age - autoimmune disease that occurs when certain immune cells malfunction & dont recognize the body's own beta cells - as a result, immune system cells attack & destroy many of the beta cells & the person must obtain insulin, usually by injecting the hormone into their body regularly
Added sugars
- often added to foods during processing or preparation - in baked cereal products, they contribute to the browning & tenderness of the food - ex: sucrose, HFCS (chemically similar to sucrose)
Normal fasting blood glucose levels are:
70-99 mg/dl
___________ and ______ cells, including brain cells must use glucose for energy under normal conditions
RBCs & nervous system cells
The alternative sweetener that people with PKU must avoid is:
aspartame
Carbohydrates
class of nutrients that includes substances cells can use for energy
Aspartame
- better known as "NutraSweet" or "Equal" - only small amt. is required b/c its so intensely sweet - consists of phenylalanine & aspartic acid, 2 amino acids, the molecules that comprise proteins - blamed for causing a variety of health problems (cancer, certain immune system diseases & chronic headaches); but not reliable studies have linked it to any health disorders
Insoluble Fiber
- dont dissolve in water; i.e. cellulose, lignin - rich sources: whole grain products, brown rice
Individuals who already have metabolic syndrome may reduce their risk of CVD by _________________. Lifestyle changes that can help manage these levels include _______________. If such changes do not alleviate the condition, medication may be necessary to manage blood pressure and blood lipid levels.
- lowering their elevated BP, glucose, insulin, & triglyceride levels - losing excess weight, exercising regularly, reducing intakes of salt, saturated fat, simple sugars
Diverticula
- marble size sacs that form in the lining of the colon - in most people, it does not produce symptoms, but they can bleed or become painfully inflamed when bacteria/ feces are trapped w/i them. when this occurs (diverticulitis), person may need surgery to remove damaged section of large intestine - cause is unknown, but we know theyre more likey to form in older adults
According to Dietary Guidelines, people who follow a 2000 kcal/day diet should limit their intake of added sugars to no more than ______ per day.
12 teaspoons
A triglyceride level of or greater than __________mg/dL is considered too high and a risk factor for metabolic syndrome
150
Sugar alcohols are not fully absorbed by the intestinal tract. As a result, they supply an average of ____ kcal/g.
2
In 2015, the average Am. consumed ~_________ of added sugars per day, which is almost 18% of the energy in a diet that supplies 2000kcal/day.
22 teaspoons
Syndrome
a group of signs or symptoms that commonly occur together and indicate a specific health problem
Which of the following foods have a high glycemic index? (more than 1) a. baked potatoes b. chicken breast c. fat free milk d. white rice
a. baked potatoes d. white rice
(Example) 24 g of total carbohydrate are in one serving; of this amount, there are 11 g of total sugars and 10 grams of added sugars. Each serving supplies no grams of fiber. How can you estimate the grams of starch in the serving of the food?
add the number of grams of total sugars (11 g) with that of fiber (0 g) and subtract this amount from grams of total carbohydrate (24 g), and you will find that starch comprises 13 g of the carbohydrate in a serving of the food.
Epinephrine is released from the
adrenal glands
What happens if you ignore your hunger signals and do not eat
alpha cells in pancreas secrete glucagon; glucagon opposes insulins effect by promoting the breakdown of glycogen (glycogenolysis)
These two polysaccharides, __________ and ___________, are forms of starch
amylose & amylopectin
The simple sugars in honey (are/ are not) superior to those that comprise sucrose, and your body (does/ does not) distinguish whether glucose or fructose came from honey or table sugar.
are not superior; does not distinguish
Sugars & other nutritive sweeteners
brown sugar, glucose, polydextrose, confectioner's or powdered sugar, raw sugar, Corn sweeteners, corn syrup, high fructose corn syrup (HFCS) honey, Sorbitol*, cultured corn syrup, invert sugar, Mannitol*, Date sugar, lactose, Xylitol*, Dextrose, maltose, high-maltose corn syrup, table sugar (sucrose), fructose (levulose), maltodextrin, turbinado sugar, fruit juice concentrate or concentrated, maple syrup
(glycemic index x grams of ____________) /100 = glycemic load
carbohydrate
Identify carbohydrate forms of fiber.
cellulose, hemicellulose, pectin, gums, mucilages
Under normal conditions human cells obtain a small proportion of their energy needs by converting:
certain amino acids into glucose
Ketone bodies
chemicals that result from the incomplete breakdown of fat; muscle & brain cells can use these for energy
Soluble fiber __(increases/ decreases)__ the absorption of cholesterol-rich bile acids into the blood
decreases
The results of scientific studies ___(do/ do not)___ indicate that eating sugary foods or drinks increases children's physical activity levels, causes ADHD, or has any other negative effects on their behavior
do not
Like glucagon, ___________ increases the supply of glucose and fatty acids in the bloodstream, but the hormone can also make a person with hypoglycemia feel irritable, restless, shaky, hungry, and sweaty.
epinephrine
Which foods have a low to moderate glycemic index? a. fat free milk b. carrots c. cotton candy d. raw apples
everything but cotton candy
Symptoms of diabetes includes:
excessive thirst, urination, hunger, fatigue, lethargy, sores that dont heal, blurry vision, fruity/ winelike breath
The body can convert amino acids into glucose, but it cannot use ________ to make glucose.
fatty acids
If you're trying to lose weight, it may be more helpful to add more high- ______________ foods to your diet because these foods tend to be more filling resulting in satiety.
fiber
Lactose
forms when a galactose molecule bonds to a glucose molecule - sources: certain animal products--> milk, some products made from milk (i.e. yogurt, ice cream)
Name the major monosaccharide found in the body
glucose
Cells need a small amt. of _______ to metabolize fat for energy properly.
glucose - ex: When a person is fasting or starving, or follows a very low-carb/high-protein diet (i.e. the Atkins diet), their cells must use greater-than-normal amounts of fat for energy. Under these conditions, there is not enough glucose available for cells to metabolize the fat efficiently, and cells form more ketone bodies than usual.
What are the 3 most important dietary monosaccharides
glucose, fructose, galactose
What sugars are commonly found in foods
glucose, fructose, sucrose
The liver uses glycerol to produce:
glucose. & most cells, including muscle cells, can metabolize fatty acids for energy
The chains of __________ are more highly branched than those of amylopectin.
glycogen
The storage form of glucose in the body is called
glycogen
What nutrients are listed underneath "total carbohydrate" on a Nutrition Facts panel?
grams of fiber, total sugar, added sugars
Pregnant women w/ poorly controlled diabetes or gestational diabetes are more likely to have _______________________ than women w/ diabetes who manage their blood glucose properly
miscarriages, stillbirths, premature deliveries, give births to babies who are too large & have difficulty controlling their own blood glucose levels
Sport drinks & sports or energy bars often include _____________ such as maltodextrin & dextrin. Regardless of its source, each gram of starch supplies _____ kcals.
modified starches; 4 kcals
Fiber is mostly made up of ____________ and connected by bonds that humans cant digest.
monosaccharides
What are the 2 major sites for glycogen formation & storage?
muscles & liver
Soluble Fiber
- dissolve/ swell in water; i.e. pectins, gums, mucilages - are metabolized by intestinal bacteria - improves heart health by binding to bile components in the GI tract - rich sources: oat bran, oatmeal, beans, apples, carrots, oranges, other citrus fruits, psyllium seeds
If a whole grain product is made from ground, cracked, or flaked cereal grains, the forms must contain the starchy endosperm, oily germ, & fiber rich bran seed components in the same relative proportions as they exist in the _______________.
intact grain
A waist circumference greater than or equal to ______ inches for men and ______ inches for woman is considered too large & is a risk factor for the metabolic syndrome.
40 inches for men; 35 inches for women
How many americans were diagnosed with pre-diabetes in 2012?
86 million
About _____% of pregnant Am. women develop a form of diabetes called _____________, usually after the 5th month of pregnancy.
9%; gestational diabetes
