NUTR 202 FLASHCARDS: Exam #1

Nutrition

The study of the interaction between nutrients, the body’s function, and health; compared to other disciplines, it is a “young” science

Nutrigenomics

The study of how dietary compounds alter the expression and/or structure of an individual’s genetic makeup, thus affecting health and risk of disease; a newly emerging integrated science

Nutrients

Substances that the body requires for energy, regulation of bodily processes, and structure

Essential Nutrient

A nutrient that the body can only acquire through food consumption

Non-Essential Nutrient

A nutrient that the body can produce in adequate amounts

Calorie

Scientific unit used to measure energy

Kilocalorie

Scientific unit used to measure food energy

Macronutrients

Nutrients that provide energy; include carbohydrates, fats, proteins, and water

Micronutrients

Nutrients that support metabolism; include vitamins and minerals

Carbohydrates

Macronutrients that are primarily responsible for providing energy/calories; produced by photosynthesis in plants; include sugars, starches, and fibers; composed entirely of carbon, oxygen, and hydrogen; provide 4 kcal/g

Photosynthesis

Process in which carbon dioxide from the atmosphere, water from soil, and energy from the sun interact in a biochemical reaction to produce glucose (carbohydrates)

Simple Carbohydrates

Carbohydrates that contain less than 10 monosaccharide units; monosaccharides (glucose, fructose, and galactose) and disaccharides (sucrose, maltose, and lactose)

Glucose

Most common form of carbohydrates; circulates in the blood

Fructose

Found in abundance in fruits and honey

Galactose

Rarely exists as an individual compound in foods; component of lactose in milk (binds with glucose to form); found in pectin and other dietary fibers

Complex Carbohydrates

Carbohydrates that contain more than 10 monosaccharide units (up to thousands); polysaccharides

Sweeteners

Used to flavor foods

Non-Nutritive Sweeteners

May be natural or synthetic and do not provide calories; some examples include aspartame (Equal), acesulfame-K (Sunett), saccharin (Sweet’n Low), and sucralose (Splenda)

Nutritive Sweeteners

Can be digested and yield calories; some examples include sucrose, fructose, honey, molasses, and high fructose corn syrup (may contribute to excess calories)

Lipids (Fats)

Macronutrients that are primarily responsible for providing energy, but are also involved with structure and regulation; include triglycerides (type most commonly consumed), phospholipids, and sterols; common food sources include oils and butter; composed entirely of carbon, oxygen, and hydrogen (contain twice as many hydrogen atoms as carbohydrates); provide 9 kcal/g

Protein

Macronutrients that are primarily responsible for supporting growth and maintenance and repair of tissue; composed primarily of carbon, oxygen, and hydrogen, but also contain nitrogen; provide 4 kcal/g

Metabolism

Biochemical activity that occurs in cells; either releases energy from nutrients or uses energy to create other substances

Vitamins

Micronutrients that are required in small amounts in order to maintain normal body function; separated into two broad categories: fat soluble and water soluble; do not need to be digested

Fat Soluble Vitamins

Do not dissolve in water; absorption facilitated by dietary fat; transported in chylomicron; can be stored in the body for long periods of time; do not need to be consumed daily

Water Soluble Vitamins

Dissolve in water; absorbed into the blood; not stored in the body - excreted mostly through urination

Minerals

Micronutrients that are inorganic compounds necessary for structure and regulating processes in the body; separated into two broad categories: macrominerals and microminerals; absorbed all along the small intestine - sodium is best absorbed with glucose and amino acids, however some nutrients, such as iron and calcium, are absorbed based on the body’s need

Macrominerals (Major Elements)

Required by the body in amounts equal to or in excess of 100 mg/day

Microminerals (Trace Elements)

Required by the body in amounts less than 100 mg/day

Electrolyte

A mineral that assumes a charge when dissolved in water; includes sodium, potassium, and chloride

Water

Helps the body to break down and process food during digestion; most is absorbed in the small intestine, however a small amount is absorbed in the large intestine

Alcohol

Yields energy but has no real function in the body; some is absorbed in the stomach, however most is absorbed in the small intestine; travels to the liver for detoxification; provides 7 kcal/g

Phytochemicals

Chemical compounds in plants that have various effects on bodily functions; not classified as nutrients, but play an important role in health; more commonly referred to as “superfoods”

Factors Which Influence the Food Choices That We Make

Taste, environment, culture/tradition, family, finances, convenience, the media, age, and health issues

Malnutrition

Poor nutrition status; some examples of diseases strongly linked to this include osteoporosis, diverticulosis, obesity, heart disease, diabetes, and cancer

Undernutrition

Having inadequate amounts of a specific nutrient; can occur worldwide; most prominent in sub-Saharan Africa and Asia

Nutrients Most Likely to Be Deficient in Diets

Protein, iron, iodine, vitamin A, and zinc

Biological Causes of Undernutrition

Inadequate food intake or frequent infections

Societal Causes of Undernutrition

Limited access to food, civil conflict, or overpopulation

Overnutrition

Having too much of a specific nutrient

Recommended Dietary Allowance (RDA)

Created in 1941 in response to the poor nutrition statuses of men drafted for WWII; average daily nutrient intake level sufficient to meet the nutrient requirement of nearly all (97-98%) healthy individuals in a particular age, sex, and life-stage group

National Academy of Sciences

Expanded upon RDAs by creating Dietary Reference Intakes (DRIs), which now include the limits of nutrient intake

U.S. Department of Agriculture (USDA)/U.S. Department of Health and Human Services (HHS)

Worked together to develop the food and nutrition policy

Dietary Guidelines for Americans

Diet and lifestyle recommendations; first published by the USDA and the HHS in 1980

Expanded Food and Nutrition Education Program (EFNEP)

Education used to assist in improving diet and lifestyle; USDA funded

Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)

Exists in order to improve nutrition during pregnancy, infancy, and childhood - pregnant/lactating women and children are at the greatest risk for undernutrition

Registered Dietician (RD)

Completed a degree in dietetics and nutrition from an accredited university; completed an accredited internship experience; passed a national examination in order to earn their credentials

Reputable, Peer-Reviewed Nutrition Journals

Journal of Nutrition and Journal of Clinical Nutrition

Scientific Method/Gold Standard Clinical Research Studies

Used to develop nutrition recommendations

Healthy Diet

Incorporates a variety of foods that include balance and moderation in order to help maintain a healthy body weight

Variety

Involves eating different types of food within each food group

Balance

Involves incorporating foods from all food groups into your daily plan; stabilizing calories consumed with calories expended during physical activity

Moderation

Involves avoiding overconsumption of any food or food group; focusing on portion sizes

Nutrient Density

Nutrient content of food relative to its calorie content; foods provide more nutrients per kilocalorie than less nutrient-dense foods

Energy Dense

Foods that are higher in energy but lower in weight or volume; typically have more calories and less nutrients (vitamins/minerals)

Empty Calories

Calories that have little to no nutrient content; some foods that are energy dense may also be considered these

Dietary Guidelines

Released every ten years; research showing Americans were over consuming certain foods (fat, cholesterol, sodium, etc.); designed to improve the quality of American’s diet choices

Healthy People 2030

Set of government objectives which include dietary and health goals targeted at improving the overall health of the U.S. population (started in 1979); exists in 23 priority areas with more than 358 objectives; created through collaborative effort - scientists, federal and state agencies, and public feedback helps to establish data which in turn helps drive changes in the next decade for improvement on certain areas of topics

Dietary Reference Intakes (DRIs)

Designed for healthy people; categorized based on age group and life stage; used to assess and improve the nutritional status of Americans by interpreting food consumption records of populations, establishing standards for food assistance programs, planning school menus, and establishing guidelines for nutrition labeling

Estimated Average Requirement (EAR)

Average daily nutrient intake level estimated to meet the requirement of half of the healthy individuals in a particular age, sex, and life-stage group

Adequate Intake (AI)

An intake (not a requirement) that is likely to exceed the actual requirements of almost all individuals in a particular age, sex, and life-stage group; established when scientific evidence is not sufficient to determine an RDA

Tolerable Upper Intake Level (UIL)

The highest average daily nutrient intake level likely to pose no risk of adverse health effects for nearly all people in a particular age, sex, and life-stage group

Chronic Disease Risk Reduction Intake (CDRR)

The level above which intake reduction is expected to reduce chronic disease risk within an apparently healthy population; specifically used for sodium and potassium levels

Estimated Energy Requirement (EER)

General recommendation for how many calories a person should consume in a day; influencing factors include age, gender, height, weight, and level of physical activity

Acceptable Macronutrient Distribution Range (AMDR)

Provides recommendations for the amounts of calories which should be consumed from carbohydrates, fats, and proteins respectively; used to balance nutrient intake and reduce the risk of chronic conditions

Adults AMDR (Proteins)

10-35%

Adults AMDR (Fats)

20-35%

Adults AMDR (Carbohydrates)

45-65%

USDA MyPlate

A daily plan for food intake; includes sections for vegetables, fruits, grains, protein, and dairy foods; replaced the old food guide, MyPyramid, in 2011

Food and Drug Administration (FDA)

Regulates food labeling required for most packaged foods

Food Safety and Inspection Service of the USDA

Regulates the labeling of meat, poultry, and fresh eggs

Nutrition Facts Label

Describes the nutritional content of food products; required on food labels - only some foods are exempt; can assist with meal planning

Health Claims

Statements made about a product that link it or some of its ingredients to a reduced risk of disease; must be approved by the FDA

Authorized Health Claims

Supported by extensive scientific evidence and experts in the scientific community (must submit to the FDA); some examples include calcium and osteoporosis, vegetable/fruit intake and cancer, and dietary sugar and dental cavities

Qualified Health Claims

Supported by a scientific body of experts and based on emerging scientific evidence; the claim is greater than if the evidence suggests that the claim is not valid; some examples include antioxidant vitamins and cancer and omega-3 fatty acids and coronary heart disease

Authoritative Health Claims

Claims backed and requested by a body of scientific experts within the U.S. government (CDC) or the National Academy of Sciences; wording must contain “may”; an example is “whole-grain foods may reduce the risk of heart disease”

Nutrition Content Claims

Describe the level of a particular nutrient in a food item; must be approved by the FDA; some examples include “free” (sugar-free, fat-free, etc.), “low” (low-fat, low-sodium, etc.), “lean”, “extra lean”, “high”, “good source”, “reduced”, and “less”

Structure/Function Claims

Describe an association between a nutrient or food component and a structure or function in the body; do not need to be approved by the FDA; must include a disclaimer or label; commonly seen on dietary supplements

Digestion

The process by which food is broken down into simple chemical compounds that can be absorbed and used as nutrients or eliminated by the body; primary site of this process is the small intestine

Absorption

The process of taking nutrients from the digestive system into the blood so they can be used in the body

Gastrointestinal (GI) Tract

The organs that food and liquids travel through when they are swallowed, digested, absorbed, and leave the body as feces

Primary Organs of the GI Tract

Mouth, esophagus, stomach, small intestine, large intestine, and rectum

Accessory Organs of the GI Tract

Salivary glands, liver, pancreas, and gallbladder

Transit Time

The period of time it takes food to travel the length of the digestive tract

Mechanical Digestive Processes

The initial breakdown of food; purely physical processes that do not change the chemical nature of the food; chewing, grinding, mixing, swallowing, and peristalsis are all examples of this type of process

Chemical Digestive Processes

The breakdown of large compounds into smaller units for absorption; involves the secretions of enzymes throughout the digestive tract (ex.: salivary amylase)

Defecation

Undigested and unabsorbed substances are eliminated via this process

Peristalsis

Wavelike muscular movements involved in mechanical digestion

Sphincters

Circular muscles that separate the organs of the GI tract; “one-way doors” - prevent food from flowing backwards; some complications associated with improper functioning include heartburn and vomiting

Lower Esophageal Sphincter (LES)

A ring of muscle that forms a valve at the lower end of the esophagus where it joins the stomach

Pyloric Sphincter

A ring of muscle that connects the stomach and small intestine; 3 ml of chyme squirted at intervals into the small intestine; facilitates neutralization of stomach acid

Ileocecal Valve

A sphincter muscle situated at the junction of the ileum (last portion of your small intestine) and the cecum (first portion of your large intestine); prevents reflux of waste into small intestine

Why must digestion occur before absorption?

Complex macronutrients must be broken down into smaller units before they can be absorbed; examples of this include carbohydrates, proteins, and fats

Which food components do not require digestion in order to be absorbed?

Water, minerals, vitamins, and smaller molecules (ex.: glucose)

Flavor Perception

Refers to the sensations that are elicited by the stimulation of the gustatory receptors on the tongue - sweet, salty, sour, bitter, and umami (savory); 80% smell

Mouth/Esophagus

Digestive process begins here; responsible for chewing, mixing, and swallowing food; saliva is added to help lubricate food; salivary amylase is released to help break down food; bolus is formed

Bolus

A small rounded mass of a substance, especially of chewed food at the moment of swallowing

Stomach

Mixes food with gastric secretions; liquifies food into chyme; has a 1-4 liter capacity; the entrance of food stimulates the production of gastric juices including hydrochloric acid, mucus, and pepsinogen and hormone gastrin

Chyme

The pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food

Mucus

Protects the lining of the stomach from hydrochloric acid

Hydrochloric Acid (HCl)

Denatures proteins; liquefies foods; activates the enzymes pepsin and lingual lipase; helps prepare iron for absorption