Nutrition Exam 1

DRI

-Dietary Reference Intake
-a set of references to be a standard of estimated nutrient intake to ensure lower risk in chronic doses
-specify nutrient intake levels according to adequacy and toxicity
-includes vitamins, minerals, the energy nutrients, cholesterol, fiber, electrolytes, and water
-mostly for professional use

Updated Recommended Dietary allowances (URDA)

represents the average daily recommended intake to meet nutrient requirements of 98% in healthy individuals according to adequacy and toxicity
-based on specific criteria indicators (nutrient concentrations)
-meant for all age groups
-everyone that is healthy

Estimated Average requirements (EAR)

amount of nutrient estimated to meet the requirement for Half of healthy people in a particular life stage or gender group
-not based solely on the prevention of nutrient deficiencies
-consideration for reducing the risk of chronic disease
-takes bioafaliablity into account
-used to determine RDA values

Adequate Intake (AI)

recommended average daily intake thought to meet or exceed the needs of virtually all members of a group based on observed or experimentally obtained estimates of nutrient intakes by healthy people
-nutritional goal for people to achieve
-set when RDA cannot be determined

Tolerable upper intake level (UL)

highest level of average daily intake that is likely to pose no adverse health effects to almost all individuals in a general population

AMDR

acceptable macronutrient distribution ranges
-broad ranges for each energy nutrient (carbs, protein, fat) expressed as a percentage of the total calories consumed
-associated with reduced risk of chronic disorders while providing adequate intakes of essential nutrients

Estimated Energy Requirements (EER)

-similar to EAR, dietary energy intake predicted to maintain energy balance in healthy individuals with defined characteristics consistent with good health

What happens to excess protein consumed

-broken down into fatty acids and stored
-converted to glucose (depends on amino acid)
-anything not converted to glucose or fatty acid is converted to urea and excreted in urine

2 core objectives of healthy people 2023

nutrition, healthy eating
(promote health, reduce chronic disease through consumption of healthy diets and achievement/maintenance of healthy body weights

Disadvantage of polyols

(non-nutritive sweeteners)
-incompletely digested and absorbed
-GI will be bloated from cells absorbing too much water
-side effects include diarrhea, abdominal pain, gas

Essential Nutrients

something the body cannot make on its own, must be taken in from diet

primary site of macronutrient ingestion

small intestine

fats calories per gram

9

proteins calories per gram

4

carbohydrates calories per gram

4

MyPlate proportions

1/4 grain
1/4 protein
1/2 fruits and vegetables
dairy on side
-implements the GDA in a graphic directed towards all people regardless of age
-supposed to help people eat healthier, made to give consumers a healthy eating pattern

Foods High in vitamin E

sunflower oil, canola oil, olive oil, nuts

where is vitamin K synthesized

-microbiota in intestinal tract synthesizes vitamin K
-when we take antibiotics, the amount of vitamin K goes down because they kill natural intestinal bacteria that synthesize vitamin K
-eat probiotics to counteract
-large intestine

What activity can generate free radicals

smoking, tanning

what vitamin can smoking deplete

vitamin C, it is an antioxidant that is supposed to fight off free radicals

CDRR

chronic disease risk and reduction intake
-based on evidence of the beneficial effect of lowering sodium intake on cardiovascular disease risk, systolic high blood pressure, and diastolic blood pressure
-for sodium

DRI use

-Scientists and nutritionists who work in research and academic settings
-dietitians who plan menus for specific populations
-not suited for teaching people how to make healthy choices

Nutrient Density

refers to foods and beverages that provide vitamins, minerals, and other beneficial substances relative to the number of calories with little or no added sugars, saturated fat, and sodium

Lifestyle medicine

the use of evidence based lifestyle therapeutic approaches to treat, reverse, and prevent chronic disease
-plant-predominant dietary lifestyle
-regular physical activity
-adequate sleep
-stress management
-avoidance of risky substances
-pursuing other non-drug modalities to treat, reverse, and prevent chronic disease

nutrient dense foods

fruits, vegetables, whole grains, non-fat and low-fat dairy, fish and seafood, unprocessed lean meat and skinless poultry, nuts and legumes

calorie dense foods

-Proteins: Red meats, pork, chicken with skin on (roast or broil don't deep fry for your health), salmon or other oily fish, beans, whole milk, eggs, cheese, full-fat yogurt.
-Carbohydrates: potatoes, brown rice, whole grain pasta, whole grains, whole grain breads.

prominent characteristics of healthy eating

-variety
-balance
-moderation
-individually appropriate

Dietary Guidelines for Americans

1. follow a healthy dietary pattern at every life stage
2.customize and enjoy nutrient-dense foods and beverages to reflect personal choices
3. Focus on meeting food group need with nutrient dense foods and beverages and stay within calorie limits
4. Limit foods and beverages higher in added sugars, saturated fats, and sodium, and limit alcoholic beverages

added sugar guideline

less than 10% of calories per day starting at age 2; avoid foods with added sugars for those under 2

saturated fats guideline

less than 10% of calories per day starting at 2

Sodium guideline

less than 2300 mg per day, even less for children younger than age 14

alcoholic beverages guidelines

adults of legal drinking age can choose not to drink or to drink in moderation by limiting intake to 2 drinks or less in a day for men and 1 drink or less a day for women, when alcohol is consumed

monosaccharides

-simplest of all sugars
-do not normally occur as free molecules in nature but as basic components of disaccharides and polysaccharides
- most common are glucose, fructose, and galactose

glucose (aka dextrose)

-most widely distributed sugar in nature
-component of all disaccharides
-sugar into which the body converts all other digestible carbs

Fructose

-fruit sugar
-sweetest of all natural sugars
-High Fructose Corn Syrup

Galactose

-does not occur in appreciable amounts in foods
-combines with glucose to form lactose

disaccharides

made of two linked monosaccharides
-three primary are sucrose, maltose, and lactose

sucrose

-"sugar"
-glucose+fructose
-difference among sugars is the degree of refining
-occurs naturally in some fruits and vegetables

Maltose

Glucose+Glucose
-not naturally found in foods

Lactose

-Glucose+Galactose
-found naturally in milk
-least sweet of all the sugars

Polysaccarides

-more than 10 monosaccharide units
-complex carbohydrates
-do not taste sweet
-starch, glycogen, and fiber

starch

-glucose not used by plants is stored as starch (amylose and amylopectin)
-grains are the worlds major food crop and the foundation of all diets (potatoes, dried peas, beans, other starches)

Glycogen

-animal version of starch
-used to maintain blood sugar concentrations between feedings
-liver glycogen releases glucose into the bloodstream to maintain BS between meals
-no dietary source of glycogen

Fiber

-generally considered a group of polysaccharides that cannot be digested by a human enzyme
-commonly referred to as "roughage"
-can be soluble or insoluble
-can be dietary or functional
-assumed that it does not provide any calories
-source of energy for the colon lining

Soluble fiber

-delays emptying of the stomach which may affect blood sugar levels and have a beneficial effect on insulin sensitivity and help control diabetes
-lowers total LDL blood cholesterol
-sources include oatmeal, oat cereal, lentils, apples, oranges, pears, nuts, beans, flaxseeds, celery, carrots

Insoluble fiber

-do not dissolve in water and pass through the GI tract relatively intact, thus speeding up the passage of food and waste through the gut
-Act in the colon with a laxative effect which can help with chronic constipation or diverticular disease
-sources: whole wheat, whole grains, wheat bran, seeds, nuts, barley, leafy veggies, raisins, grapes, celery, cucumber, brown rice, bulgur, cabbage

Whole Grains

concise of the entire kernel of the grain: bran, endosperm, and germ

bran

fiber rich outer layer that protects the seed and contains B vitamins and trace minerals

endosperm

middle layer that contains carbohydrates along with proteins

germ

the small nutrient rich core that contains antioxidants, including vitamin E, B and healthy fats

Refined grains

rich in starch but lack the fiber, vitamins, trace minerals, fat, and phytochemical found in whole grains
-required to be enriched

1 serving of grains

15g of CHO

1 serving of starch vegetables

15g of CHO
-starch and sugars provide the majority of calories in veggies

1 serving of fruit

15g of CHO
-calories in fruit mainly come from fructose except avocado, olives, and coconut
-fiber is located in the skin

1 serving of dairy

1 cup milk is 12g CHO
1 cup cottage cheese 6g CHO

empty calories

extras, carbohydrate content varies

Starch Digestion

-begins with salivary amylase
-mostly occurs in the small intestine
-split disaccharides into monosaccharides
-95% absorbed within 1-4 hours of eating

starch absorption

absorbed through intestinal mucosa cells, undigested starch passes with stools
-fibers may impair the absorption of some minerals (calcium, zinc, iron)

starch metabolism

-fructose and galactose are converted to glucose in the liver
-liver releases glucose to maintain blood sugar level
-rise in blood sugar causes the pancreas to release insulin

postprandial state

-blood glucose concentration begins to drop
-pancreas releases glucagon
-stimulates liver to release glucose

Glycemic response

increase in blood glucose levels
-glycemic index is determined by comparing the impact on blood glucose after 50g of food sample is eaten compared to 50g or pure glucose (diabetics and athletes)
-glycemic load more accurately defines a food's impact on blood glucose levels (not reliable for choosing a healthy diet)

glucose for energy

-Primary function of carbohydrates is to provide energy for cells
• Brain is totally dependent on glucose for energy
• Spares protein and prevent ketosis

protein sparing

need to consume adequate carbohydrates or proteins will be consumed for energy

Preventing Ketosis

-without adequate glucose, fat oxidation prematurely stops at the intermediate step of ketone formation
-increased production of ketones causes nausea, fatigue, loss of appetite, and ketoacidosis
-dehydration and sodium depletion follow

Carbohydrate DRI

130g for adults and children
acceptable macronutrient distribution range is 45-65% of calories
-recommended that 1/2 of grain servings be whole grain

fiber DRI

22-28 g for women, 28-34 g for men

pyols

sugar alcohols (sorbitol, mannitol, xylitol)
-most are completely synthesized

nonnutritive sweeteners benefits

virtually calorie free
sweeter than sugar
do not raise blood glucose levels

protein composition

amino acids linked by peptide bonds

essential amino acids

9- the body cannot make them so they must be consumed in food
-histidine, phenylalanine, threonine, isoleucine, methionine, tryptophan, leucine, lysine, valine

nonessential amino acids

11- can be synthesized by the body
- alanine, glycine, proline, arginine, glutamine, serine, asparagine, glutamic acid, tyrosine, aspartic acid, cystine

protein functions

-major structural and functional component of every living cell
-body structure and framework
-enzymes
-other body secretions and fluids
-acid/base balance
-transport molecules
-other compounds
-some amino acids have specific functions in the body
-fueling the body

protein absorption

amino acids and sometimes a few dipeptides and larger peptides are absorbed through the mucosa of the small intestine

protein metabolism

Liver acts as a clearinghouse
-Retains amino acids to make liver cells, nonessential amino
acids, and plasma proteins such as heparin, prothrombin, and
albumin.
◦ Regulates the release of amino acids into the bloodstream
◦ Removes the nitrogen from amino acids so they can be burned
for energy
◦ Converts protein to fatty acids which form triglycerides for
storage in adipose tissue
◦ Forms urea from the nitrogenous wastes when calories
consumed in excess

protein synthesis

-Complicated but efficient process that quickly assembles
amino acids into proteins the body needs
-Part of what makes every individual unique is the minute
differences in body proteins

protein turnover

continual renewal or replacement of proteins
-body proteins vary in their rate of turnover

metabolic pool

-Contains supply of each amino acid
-Consists of recycled amino acids from body
proteins that have broken down and also
amino acids from food
-In a constant state of flux

nitrogen balance

reflects the state of balance between protein breakdown and protein synthesis
-positive when synthesis exceeds breakdown
-negative when breakdown exceeds synthesis

Nitrogen intake (protein intake/6.25) - nitrogen output (urinary urea nitrogen + 4(used in body))

protein catabolism for energy

-overtime loss of lean body tissue occurs
-loss of 30% body protein causes decreased muscle strength, altered immune function, altered organ function, ultimately death

complete proteins

-high biologic value
-provide adequate amounts and proportions of all essential amino acids needed for protein synthesis necessary to support tissue growth and repair
-animal and soy proteins are complete

Incomplete proteins

-lack adequate amounts of one or more essential amino acids
-except for soy and quinoa protein, all plants are sources of incomplete proteins

complementary proteins

-two proteins that when combined provide all of the essential amino acids to support proteins synthesis

Ex. Grains+legumes
legumes+seeds
dairy+grains

protein DRI

.8g/kg
-10-35% of total calories

protein deficiency

Kwashiorkor- results from acute critical illnesses; aggressive nutritional support is used to restore metabolic balance as quickly as possible (large fluid stores in abdomen)
Marasmus- occurs secondary to chronic diseases; nutritional therapy is started slowly and advanced gradually

Lipids

-34% of energy in the human diet
-dietary fat is stored in adipose tissue
-structural fat and textural properties

three classes of lipids

-triglycerides
-phospholipids
-sterols

triglycerides

approximately 98% of fat in foods, made of the same elements as carbs but has more calories

fatty acids

-rarely free in nature and almost always linked to other molecules
-chains of carbon atoms with hydrogens attached
-vary in length and degree of unsaturation

carbon chain length

• Almost all fatty acids have an even number of
carbon atoms in their chain.
• Long-chain fatty acids (12 or more carbon atoms)
• Medium- (6-10 carbon atoms) and short-chain fatty
acids (2-4 carbon atoms)
• Classified according to the number of carbons, the
number of double bonds, and the position of the
double bonds in the chain.

Degree of Saturation

-contribute to the melting temperature of a fat
-carbon atoms are saturated when they have 4 carbons bonded
-carbon atoms are unsaturated when they have one or more double bonds
-Fatty acids can attach to glycerol molecules
-Types and proportions of fatty acids present influence the sensory and functional properties of the food fat.
-All food fats contain a mixture of saturated, monounsaturated , and polyunsaturated fatty acids

saturated Fats

-tend to be solid at room temperature
-animal fats provide about 60% of fat in the American diet
-the only vegetable fats that are saturated are palm, palm kernel, and coconut oils
-commonly known as bad fat because it raises blood cholesterol levels
-raises total LDL levels
-as cholesterol levels rise, risk of coronary heart disease increases
-may also make the inner lining of the arteries more prone to inflammation and the build up of fatty plaques

unsaturated fats

• LIQUID AT ROOM TEMPERATURE
• MONOUNSATURATED FATS ARE THE PREDOMINANT FAT IN OLIVES, OLIVE OIL,
CANOLA OIL, PEANUT OIL, AVOCADO, CASHEWS, ALMONDS, AND MOST OTHER
NUTS.
• POLYUNSATURATED FATS ARE THE PREDOMINANT FAT IN CORN, SOYBEAN,
SAFFLOWER, AND COTTONSEEDS OIL AND ALSO IN FISH.
•COMMONLY KNOWN AS “GOOD FATS” BECAUSE WHEN THEY ARE EATEN IN
PLACE OF SATURATED FATS, THEY LOWER LDL CHOLESTEROL AND RAISE HDL
CHOLESTEROL
• PART OF AN UNSATURATED FATTY ACID’S IDENTITY IS DETERMINED BY THE
LOCATION OF THE FIRST DOUBLE BOND ALONG THE CARBON CHAIN.
• LOCATION OF THE FIRST DOUBLE BOND IS SIGNIFICANT
• DETERMINES ESSENTIALITY OF FATTY ACID.

linoleic acid

the essential N-6 fatty acid
-especially abundant in plant oils

alpha linolenic acid

• THE ESSENTIAL N-3 FATTY ACID
• FOUND IN FLAXSEED, CANOLA, SOYBEAN, AND WALNUT OILS AND IN NUTS, ESPECIALLY WALNUTS
• CAN CONVERT ALPHA-LINOLENIC ACID TO EICOSAPENTAENOIC ACID (EPA) AND DOCOSAHEXAENOIC ACID (DHA) IN THE BODY
• COMMONLY REFERRED TO AS “FISH
OILS”

stability of fats

-Degree of unsaturation influences the stability of
fats.
-Polyunsaturated fats are most susceptible to rancidity
-Food manufacturers may add antioxidants or hydrogenate to prolong shelf life.

trans fats

-Hydrogenation is a process that adds hydrogen atoms to heart healthy polyunsaturated oils to saturate some of the double bonds so that the resulting product is less susceptible to rancidity and has improved function
-Adds hydrogen to liquid oils to form stable, solid sat
-Hydrogen can be added both in the natural cis position and in the trans position
-raise LDL and lower HDL cholesterol levels
-ounce for ounce these are more unhealthy than saturated fats
-FDA labeling must include trans fats
-being eliminated from commercial use

Phospholipids

-precursors to prostaglandins
-lecithin is best known
-Primary component of lipid in the membrane lipid bilayer
-Major component of lipoproteins: VLDL, LDL, HDL
-Not an essential nutrient
-Rich sources: egg yolks, liver, soybeans, peanuts,
legumes, spinach, wheat germ

Cholesterol

-a waxy sterol whose carbon, oxygen, and hydrogen molecules are arranged in a ring
-the basis for all steroid derivatives in the body
-occurs in the tissues of all animal cells membranes and myelin
-found exclusively in animals (liver and eggs)

Lipid digestion

• MINIMAL AMOUNT OF CHEMICAL DIGESTION OF
FAT OCCURS IN THE MOUTH AND STOMACH
THROUGH THE ACTION OF LINGUAL LIPASE AND
GASTRIC LIPASES, RESPECTIVELY.
• DUODENUM
• STIMULATES THE RELEASE OF THE HORMONE
CHOLECYSTOKININ
• STIMULATES THE GALLBLADDER TO RELEASE BILE
• PREPARES FAT FOR DIGESTION
–MOST FAT DIGESTION OCCURS IN THE SMALL
INTESTINE.
–END PRODUCTS OF DIGESTION ARE ABSORBED
INTO INTESTINAL CELLS.
–SMALL AMOUNT IS EXCRETED IN FECES.
–DIGESTION OF PHOSPHOLIPIDS IS SIMILAR.
–CHOLESTEROL DOES NOT UNDERGO DIGESTION;
IT IS ABSORBED AS IS.

Lipid Absorption

• ABOUT 95% OF CONSUMED FAT IS ABSORBED
• SMALL FAT PARTICLES ARE ABSORBED
DIRECTLY THOUGH THE MUCOSAL CELLS INTO
CAPILLARIES (lacteals)
• ABSORPTION OF LARGER FAT PARTICLES –
NAMELY, MONOGLYCERIDES AND LONG-CHAIN
FATTY ACIDS – IS MORE COMPLEX
• MICELLES
• RECOMBINE INTO TRIGLYCERIDES
• CHYLOMICRONS DISTRIBUTE DIETARY LIPIDS
THROUGHOUT THE BODY