Deck 4: Fiber

Question 1

Name a water-soluble, gel-forming fiber that functions in the plant as intracellular cement and that is used commercially to make jellies and to provide fiber in enteral formulas.

A) lignin
B) gum
C) pectin
D) cellulose

Answer 1

C

Question 2

Which fiber component is provided primarily by the outer layers of cereal grains?

A) lignin
B) pectin
C) fructans
D) cellulose

Answer 2

D

Question 3

Which of the following high-fiber foods are most effective in lowering serum cholesterol?

A) corn and wheat
B) chitosan and chitin
C) rice bran and wheat bran
D) oat bran and legumes

Answer 3

D

Question 4

When fibers form viscous gels in the stomach, which of the following occurs?

A) Gastric emptying is delayed or slowed.
B) Satiety is decreased significantly.
C) Digestion of fats and carbohydrates increases.
D) The nutrient diffusion rate is increased.

Question 5

Glycemic control is _____ in response to foods rich in fiber or to fiber supplements.

A) unchanged
B) improved
C) reduced
D) not known

Question 6

Dietary fiber is currently defined as

A) carbohydrates and lignin that are nondigestible by human enzymes and are intact and intrinsic in plants.
B) carbohydrates that are nondigestible by human enzymes, have been isolated, extracted or manufactured, and have been shown to have beneficial physiological effects in humans.
C) crude fiber.
D) the same as functional fiber.

Question 7

Functional fiber is currently defined as

A) carbohydrates and lignin that are nondigestible by human enzymes and are intact and intrinsic in plants.
B) carbohydrates that are nondigestible by human enzymes, have been isolated, extracted or manufactured, and have been shown to have beneficial physiological effects in humans.
C) all dietary fiber.
D) the same as crude fiber.

Question 8

Which group of high-fiber foods contains the greatest quantities of hemicellulose?

A) legumes
B) whole-grain cereals and bran
C) fruits
D) vegetables

Question 9

Pectins are part of the cell wall and middle lamella and are _____.

A) water soluble
B) gel forming
C) stable at acidic pHs
D) all of the above

Question 10

Processed foods that may have cellulose purified from wood added to them include all of the following EXCEPT _____.

A) canned green beans
B) cake mixes
C) sandwich spreads
D) fruit juice mixes

Question 11

121 20. Which fiber type is poorly fermentable?

A) lignin
B) pectin
C) gums
D) resistant starch

Question 12

Which of the following is NOT a form of resistant starch?

A) natural starch in cell walls of steel-cut oats b natural starch in hot corn starch pudding
C) starch crystals in cooled, cooked foods, such as potatoes
D) chemically modified starch, such as cross-bonded starch

Question 13

What are the hydrocolloids that are secreted at a site of injury on a plant or surround the endosperm of some seeds and that are used as thickening agents?

A) lignin
B) cellulose
C) pectins
D) gums

Question 14

What type of resistant starch is formed during food processing such as the cooking and cooling of starchy foods?

A) RS₁
B) RS₂
C) RS₃
D) RS₄

Question 15

Dietary fibers are mainly provided by

A) proteins that have been heated with sugars.
B) plant cell walls.
C) chitin and chitosan.
D) plant gums.

Question 16

The predominant source of dietary chitin is _____.

A) supplements
B) bran
C) vegetables
D) fruits

Question 17

Common food sources of fructans are _____.

A) strawberries, apples, and citrus fruits
B) whole grains
C) chicory, onions, and Jerusalem artichokes
D) legumes

Question 18

What are the homopolymers of glucopyranose found in cereal brans such as oats and barley that are effective in reducing serum cholesterol?

A) beta-glucans
B) fructans
C) fructooligosaccharides
D) chitin

Question 19

What is the primary noncarbohydrate component of fiber?

A) gums
B) hemicellulose
C) lignin
D) cellulose

Question 20

Which of the following fibers stimulate the growth of bifidobacteria and thus are considered prebiotics?

A) lignins
B) fructans
C) beta-glucans
D) cellulose

Question 21

Phytochemicals are

A) new vitamins being found in plants.
B) non-nutrient plant compounds that are biologically active.
C) mineral compounds derived from plants.
D) another name for herbal medicines.

Question 22

Which of the following is NOT a typical gastrointestinal response to ingestion of dietary fiber?

A) increased glucose absorption
B) delayed gastric emptying
C) increased bile-acid excretion
D) increased fecal bulk

Question 23

Soy is rich in

A) glucosinolates.
B) lignans.
C) organosuphides
D) isoflavones.

Question 24

Which of the volatile short-chain fatty acids is said to have antineoplastic properties affecting colorectal cancer?

A) acetic
B) propionic
C) butyric
D) capric

Question 25

By what mechanism do soluble fibers decrease the absorption of lipids?

A) by increasing growth of bacteria that use the lipids
B) by lowering blood cholesterol
C) by adsorbing/interacting with lipids
D) by reducing mineral absorption

Question 26

Three short-chain fatty acids produced by bacterial fermentation of fiber in the colon are _____.

A) lactate, sodium acetate, and carbon dioxide
B) bifidobacteria, lactobacilli, and streptococci
C) methane, sulfur dioxide, and hydrogen
D) acetic, propionic, and butyric

Question 27

Which of the following types of foods contributes the most fiber in a usual serving?

A) whole-grain breads
B) legumes, beans
C) meat, dairy
D) leafy vegetables

Question 28

Flavonoids are phytochemicals that can function in the body as

A) free radicals.
B) saponins.
C) antioxidants.
D) conjugates.

Question 29

Fiber lowers serum cholesterol concentrations by all of the following mechanisms EXCEPT _____.

A) decreased transit time
B) increased excretion of bile acids in the feces
C) a shift of bile acid pools toward chenodeoxycholic acid, which inhibits HMG-CoA reductase
D) production of propionic acid from gut fermentation of fiber

Question 30

The main benefits of prebiotics relate to their capacity to promote the _____ of bacteria and production of _____.

A) growth; amino acids
B) growth; fatty acids
C) death; amino acids
D) death; fatty acids

Question 31

Which of the following is considered a prebiotic?

A) brans
B) galactose
C) fructans
D) lactose

Question 32

Prebiotics are naturally abundant in:

A) cow's milk yogurt.
B) asparagus.
C) mayonnaise dressings.
D) oatmeal.

Question 33

All of the following are among the seven top-selling herbs in America EXCEPT

A) hawthorn.
B) ginkgo biloba.
C) saw palmetto.
D) ginseng.

Question 34

Which volatile short-chain fatty acid is believed to lower serum cholesterol by acting as an inhibitor of cholesterol biosynthesis?

A) acetic
B) butyric
C) propionic
D) palmitic

Question 35

What characteristics of fiber may protect against developing colon cancer?

A) Fibers adsorb primary bile acids to promote their excretion.
B) Fibers increase fecal bulk and dilute carcinogen concentrations.
C) Fibers can be fermented to butyric acid, which may slow proliferation of cancer cells.
D) All of the above

Question 36

Interactions have been reported between gingko biloba and

A) aspirin and warfarin.
B) oral contraceptives.
C) diuretics.
D) hypertensive medications.

Question 37

What mineral that is released in the colon by fermentation of fiber is considered to improve the proliferation of normal colon cells, thus inhibiting cancer?

A) zinc
B) riboflavin
C) iron
D) calcium

Question 38

The kind and amount of phytochemicals in a plant varies with

A) environmental conditions during plant growth.
B) stage of ripeness.
C) storage conditions.
D) all of the above

Question 39

Regulation of herbal supplements in the United States

A) is separate from the regulation of vitamins.
B) guarantees that the herbal supplements are safe and effective.
C) falls under the Dietary Supplement Health and Education Act of 1994.
D) requires that therapeutic claims be clearly listed on the label.

Question 40

What is the desirable amount of dietary fiber recommended for most population groups each day?

A) 10-15 g
B) 20-40 g
C) 50-60 g
D) 70-90 g

Question 41

The use of prebiotics for blood glucose regulation:

A) is not currently recommended.
B) is recommended for those with prediabetes but not diabetes.
C) has been proposed but not investigated through research.
D) is more effective than the use of other dietary fibers.

Question 42

Which of the following is a mechanism for the constipation relief provided by fructooligosaccharides and inulin?

A) decreases in microbial mass
B) decreases in osmotic pressure in the colon
C) shortened transit time
D) increased time available for water absorption

Question 43

At this time, what is the state of the evidence for prebiotics use to prevent or treat diarrhea?

A) data is promising but inconclusive
B) most studies find no benefit
C) benefits were found for adults but not infants
D) no clinical trials in this area have been conducted

Question 44

Dosages of ~2.5 to 10-15 g/day of prebiotics taken for at least _____ are required to increase the intestinal flora population.

A) 3 months
B) 1 month
C) 2 weeks
D) 1 week