TAMU NUTR 202 Lynch exam 1

Carbohydrates (energy, function, and composition)

- Provide energy

- 4 kcal/gram

- composition: carbon, oxygen, and hydrogen

Lipids (energy, function, and composition)

- energy storage

- 9 kcal/gram

- composition: carbon, oxygen, and hydrogen (2x as many hydrogen atoms as carbs)

Protein (energy, function, and composition)

- support growth and maintenance/ repair of tissue

- 4 kcal/gram

- carbon, oxygen, hydrogen, and NITROGEN

Water (energy and function)

- regulate body temp, cell hydration and lubrication

- 0 kcal/gram

Macronutrients include...

carbohydrates, lipids, proteins & water

Vitamins (energy and function)

- regulate biochemical reactions, antioxidant

- 0 kcal/gram

Minerals (energy and fucntion)

- regulate biochemical reactions, provide structure

- 0 kcal/gram

Micronutrients include...

vitamins and minerals

Micronutrients support what function...

metabolism

Metabolism

- biochemical activity that occurs in cells

- release energy from nutrients

- use energy to create other substances (i.e. making protein)

Vitamins and categories of vitamins

- Vitamins: organic nutrients that required in small amounts to maintain normal body function.

- Fat soluble: do not dissolve in water, can be stored in the body for long periods of time, and do NOT need to be consumed daily.

- Water soluble: dissolve in water, not stored in body, need to be consumed daily, excreted mostly through urine.

Minerals and and categories of minerals

- Minerals: inorganic compounds necessary for structure and regulating processes in the body.

- Macromineral (major elements): required by the body in amounts EQUAL to or GREATER than 100 mg per day!!

- Micromineral (trace elements): required by body in amounts LESS than 100 mg per day.

An electrolyte is...

- a mineral that assumes charge when dissolved in water

- it includes sodium, potassium, and chloride.

Alcohol (energy and function)

- 7 kcal/gram

- yields energy but has NO function in body

Phytochemicals

- NOT classified as nutrients

- are chemical compounds found in plants that have various effects on body functions

- play an important role in health

- "superfoods"

- ex: kale

- Block inflammatory pathways

- the richer the color... the more phytochemicals!

Why do we make the food choices we do? (reason #1)

Taste!

Malnutrition and the 2 major types

- Malnutrition: poor nutrition status

- 2 major types:

1. Undernutrition: inadequate amounts of specific nutrients (ex: calories)

2. Overnutrition: too much of a specific nutrient (ex: calories)

- some individuals have both (ex: too many calories and not enough protein)

Undernutrition

- inadequate nutrition resulting from lack of food or failure of the body to absorb or digest nutrients properly

- can occur worldwide

- most likely to be deficient in diets: protein (#1)

nutrigenomics

The study of how nutrition interacts with specific genes to influence a person's health

nutrigenetics

effects of genes on nutritional health, such as variations in nutrient requirements and responsiveness to dietary modifications

A healthy diet incorporates...

- variety of foods

- balance (incorporates foods from all food groups)

- moderation (portion control)

Nutrient density

- loaded in nutrients, low in calories

- nutrient content of food relative to its calories

Empty calories

- lots of calories, low or NO NUTRIENTS

- calories that have littlen

Dietary Guidelines for Americans

recommendations on diet and lifestyle to reduce disease risk for those over the age of 2

Fortified foods

foods with nutrients ADDED to them (weren't there before!)

Enriched foods

nutrients are added back that were REMOVED during PROCESSING

Dietary References Intakes (DRIs)

- Umbrella term

- First dietary standards

- maintain health and prevent deficiencies

What is the DRIs designed for and how are they categorized?

DRIs are designed for healthy people and are categorized based on age group and life stage

What do the DRIs include?

- Estimated Average Requirement (EAR)

- Recommended Dietary Allowance (RDA)

- Adequate Intake (AI)

- Tolerable Upper Intake Level (UL)

Estimated Average Requirement (EAR)

value assigned to a nutrient that would meet the needs of 50% of the people of a specific group.

Recommended Dietary Allowance (RDA)

recommended intake required to meet daily nutrient needs for 97-98% if all individuals in a specific group.

Adequate Intake (AI)

the value assigned to a nutrient if some scientific evidence is available, but not quite enough to establish a recommendation with certainty.

Tolerable Upper Intake Level (UL)

the highest level of daily nutrient intake that poses little risk of adverse health effects to healthy individuals.

Estimated Energy Requirement (EER)

general recommendation for how many calories a person should consume in a day

Acceptable Macronutrient Distribution Range (AMDR) (definition and goal)

- recommendations for amount of calories from carbohydrates, fats, and proteins

- goal: balance nutrient intake, reduce risk of chronic conditions

Daily recommendation for: Grains, Vegetables, Fruits, Dairy, and Protein foods

- grains: 6 ounces

- vegetables: 3 cups

- fruits: 2 cups

- dairy: 3 cups

- protein foods: 5 1/2 ounces

Food Labeling (FDA and USDA)

- FDA: regulates food labeling required for most PACKAGED foods

- USDA: regulates the labeling of meat, poultry, and fresh eggs

Nutrition Facts Label

- describes nutritional content of food products

- required on food labels (some foods exempt)

- can assist with meal planning

Updated Nutrition Facts Label include...

- bolder serving size

- larger calorie label

- now has "added sugars"

Daily Values

- based on EER

- nutrient standards used on food labels

- based on 2000 kcal diet (not everyone will require this amount, some more, some less)

How can you determine if a nutrient is "high" or "low" in a food product? (by looking at a nutrition facts label)

- "5%" or less is LOW (ex: 0% cholesterol is low)

- 20% or more is HIGH (ex: 20% added sugars is high)

Label Claims (3 categories)

- health claims (mention of disease or condition) (ex: mention lower cholesterol as part of a "heart healthy diet")

- nutrient content claims (describe level of a nutrient in a food) (ex: 50% less sugar)

- structure/function claims (describe role of nutrient on the body, NO MENTION OF DISEASE) (ex: helps build stronger bones!)

Digestion occurs in the ___ & consists of...

- gastrointestinal (GI) tract (stomach)

- series of organs, outer layers of muscles, inner mucosal and absorptive cells

Functions of GI tract (digestion, absorption, and transit time)

- digestion: move food through the GI tract, break down of food to smaller compounds, primary site is in small intestine.

- absorption: cross lining of intestine to enter body (external to internal environment)

- the period of time it take food to travel the length of the digestive tract is the TRANSIT TIME (mouth to booty). (NOTE: decreasing transit time means it goes faster, increasing it means it goes slower)

Digestion: Mechanical and chemical processes

- mechanical: chewing, mixing and peristalsis (wavelike muscular movements, moves food forward through GI tract)

- chemical: secretions and enzymes (proteins), break down of large compounds into smaller units for absorption.

- undigested and unabsorbed substances eliminated by defecation (evacuate to the toilet)

Segmentation of digestive processes

- Sphincters: circular muscles that separate organs of GI tract ("one-way doors"), prevent back flow

- 3 main sphincters: lower esophageal sphincter, pyloric sphincter, ileocecal valve

- complications associated with improper function: heartburn and vomiting

Why must digestion occur before absorption?

- complex macronutrient (carbs, proteins, fats) must be broken down to smaller (monosaccharides) units to be absorbed

Food components that do not require digestion in order to be absorbed:

- water

- minerals

- vitamins

- smaller molecules (ex: glucose)

Flavor perception is 80% .....

smell (strong connection between brain, digestive system, and smell, taste receptors in nose)

Mouth and esophagus: Mechanical and Chemical digestion

- digestive process begins in the MOUTH

- mechanical digestion: chewing, mixing, and swallowing

- chemical digestion: saliva is added to help lubricate food, enzymes are released (salivary amylase - break down carbs), bolus formed (the food after you've chewed it and stuff)

what does it mean when we see "-ase" at the end of a word

-ase means its an enzyme!

Mechanical Digestion in the stomach

- mixes food with gastric secretions

- liquifies food into chyme (food that you swallow + hydrochloric acid)

- 1-4 liter capacity

Chemical digestion in the stomach

- entrance of food stimulates production of gastric juices (hydrochloric acid, mucus, pepsinogen and hormone gastrin)

Mucus in the stomach

- protects the lining of the stomach from HCI (made by goblet cells)

- contains lots of water, proteins, and carbs

Hydrochloric acid (HCI)

- denatures (changes shape) proteins

- activates the enzymes pepsin and lingual lipase

- made by parietal cells

- digestion of proteins

Intrinsic Factor

- essential for absorption of vitamin B12

- made by parietal cells

- think of IF and B12 as besties

pepsinogen

- inactive form of pepsin (-ogen = inactive or deactivated)

- comes from chief cells

- packman example

- affiliate protein and pepsin

Hormones: Gastrin

- control movement of the stomach and secretion of HCI

rugae

stomach wrinkly looking stuff that allows the stomach to expand and conserves space on and empty stomach

food leaves the stomach and enters the small intestine: Pyloric Sphincter

- seperates stomach from small intestine

- 3 mL of chyme squirted at intervals into small intestine (facilitates neutralization of stomach acid) (opens roughly once every 1-3 mins)

The small intestine is the primary site of digestion and absorption: 3 sections

- duodenum

- Jejunum (where most digestion and absorption occurs)

- ileum

The small intestine is the primary site of digestion and absorption: nutrient absorption assisted by

- vili (increase surface area 10x the tissue projections)

- microvili (extend from vili into lumen (interior) of small intestine) (secreted digestive enzymes)

The plicae circulares

- increases surface area by 3 times

- bumpy/wrinkly weird stuff

- small intestine

Villus

- Fingerlike projection of the inner surface of the small intestine that functions in absorbing nutrients

- capillaries in them

- Yellow = lymphatic vessels -> lacteal absorb fat

Accessory organs facilitate digestion in small intestine: Pancreas, liver, and gallbladder

- pancreas: secretes alkaline bicarbonate which helps neutralize acidic chyme from stomach

- liver: produces bile (bile is 97% water, 3% cholesterol, is an emulsifier (water and fat mix like dressing).

- gallbladder: stored and releases bile (this helps in digestion of fats)

Absorption: water soluble and fat soluble nutrients

- water soluble nutrients are absorbed through intestinal wall (capillaries- carbs and proteins, carry nutrients to liver)

- fat and fat soluble substances are absorbed into lacteals (lipids) and then travel through lymph system.

almost all nutrients are absorbed in...

small intestine

small intestine: Duodenum and upper part of jejunum

- most minerals, except for electrolytes (sodium, potassium, and chloride)

small intestine: jejunum and upper ileum

- carbs, amino acids, and water soluble vitamins (capillaries)

small intestine: terminal segment of ileum

- lipids and fat soluble vitamins

- vitamin B12

small intestine: digestive contents at terminus of ileum

- some water, plant fibers, indigestible items and bacteria

undigested food components move to...

the large intestine

large intestine: ileocecal valve

- seperated ileum from cecum of large intestine

- prevents reflux of waste into small intestine

large intestine

- 5' long

- ~ 12-24 hour transit time ( fiber and exercise ca decrease this AKA make it go faster)

- functions: move studd (propulsion), ABSORPTION of WATER and sodium, preparation of waste for defecation.

Microbiota maintain health and function of large intestine

- large intestine contains ~ 100 trillion bacteria

- produce vitamin K (about 80% comes from E Coli in large intestine) and some B vitamins

- ferment (break down) plant fibers to short chain fatty acids

- metabolize any remaining nutrients

Lactose intolerant

- colon bacteria break down and ferment lactose which leads to gas and discomfort

what is maltase made up of

- glucose

- glucose

what is sucrase made up of

- glucose

- fructose

what is lactace made up of

- glucose

- galactose

Chylomicron

- emulsifier

- made up of: phospholipids, cholesterol, protein, and triglycerides

digestion and absorption of other food components: vitamins

- no digestion needed

- fat soluble vitamins: absorption facilitated by dietary fat (transported in chylomicron)

- water soluble vitamins: absorbed into the blood (vitamin B12, requires IF for absorption, absorbed in distal ileum)

digestion and absorption of other food components: alcohol

- some alcohol is absorbed in stomach

- most is absorbed in the small intestine

- travels to the liver for detoxification

digestion and absorption of other food components: minerals

- absorbed all along the small intestine

- sodium is best absorbed with GLUCOSE and AMINO ACIDS

- some nutrients are absorbed based on bodies NEEDS (ex: iron & calcium)

digestion and absorption of other food components: water

- most absorbed in small intestine (small but significant amount in large intestine)

Conditions of GI tract: Ulcer or peptic ulcer

- erosion that occurs in lining of stomach or upper part of small intestine

- primary cause: Heliobacter Pylori or H. Pylori

- routes of transmission: oral-oral and fecal-oral exposure (treatment: antibiotic)

- other causes of ulcers: regular use of aspirin, excessive use of alc, smoking

constipation

- what it does: bowel movement diffiult

- what cause it: low fiber, not enough exercise, ignoring urge to defecate

- treatment: 30g of fiber per day

diarrhea

- what it does: watery stool

- what causes it: something isn't allowing body to absorb WATER

- treatment: avoid dehydration, avoid dairy and high-sugar foods

Heartburn

- what it does: produces pain in the chest when stomach acid reflux

- what causes it: overweight (pressure on sphincter causes it to open when it shouldn't and allows reflux up), pregnancy, diet

- treatment: limit foods that increase symptoms, lose weight

Lactose Intolerance

- inability to break down lactose because of a lack of the enzyme lactase

- surgery and medication

- limit intake of dairy products

Irritable Bowel Syndrome (IBS)

- affects the large intestine and leads to cramping, diarrhea, and constipation

- overly sensitive muscles and nerves of the large intestine that may react more to stress or certain foods

- increase fiber in diet, probiotics, avoid foods that trigger it

Ulcerative Colitis

- chronically inflames the large intestine

- heredity and an "overactive" immune system

- eat omega-3, change in diet

Maintaining a Healthy Digestive Tract: Probiotic

- live microorganisms that can have a beneficial effect on health

- source: yogurt, sauerkraut

Maintaining a Healthy Digestive Tract: Prebiotic

- non-digestible (fiber) carbohydrate sources used to support metabolism of microbes in large intestine

- source: asparagus, oatmeal

combinations of Probiotics and Prebiotics are..

symbiotics

Acceptable Macronutrient Distribution Range (AMDR) requirements

- protein: 10% - 35%

- fat: 20% - 35%

- carbohydrates: 45% - 65% (may change depending on personal goals like weight gain or loss)

Types of Carbs

- simple: LESS than 10 monosaccharide units (you CAN have a polysaccharide that is a simple carb)

- comples: MORE than 10 monosaccharide units (all complex are poly)

Simple carbs: Monosaccharides

- group of SINGLE molecules used to assemble all carbs

- consists of one basic chemical ring

Simple carbs: Monosaccharides consist of

- glucose: most common form, circulates in blood

- fructose: found abundantly in fruits and honey

- galactose: rarely exists as individual compound in foods, component of lactose in milk, found in pectin and other dietary fibers

- C6H12O6: chemical formula for all 3 but each have a different arrangement

Simple carbs: Disaccharides

- composed of 2 monosaccharides liked together by a chemical bond

- Sucrose: fructose and glucose

- Maltose: glucose and glucose

- Lactose: glucose and galactose

Flavoring and Sweetening Foods: Non-Nutritive Sweeteners

- may be natural or synthetic and do NOT provide calories, isn't processed and basically goes right through you