Nutrition, Digestion, and Dietary Guidelines Flashcards

Comprehensive vocabulary flashcards covering basic nutrition concepts, food choices, dietary guidelines, DRI standards, and gastrointestinal digestion and absorption from Chapters 1, 2, and 3.

Nutrition

The science that studies all interactions that occur between living organisms and food.

Nutrients

Substances in food that provide energy, structure, and help regulate body processes.

Food Environment

The physical, economic, and social factors that affect eating habits and patterns.

Essential Nutrients

Nutrients that must be provided by the diet because the body cannot make them or make enough of them to support life.

Phytochemicals

Substances found in plant foods that are not essential for life but may possess health-promoting properties.

Kilocalorie (kcal)

A unit of heat used to express the amount of energy provided by foods, commonly referred to as calories.

Macronutrients

Nutrients required by the body in large amounts, consisting of water, carbohydrates, proteins, and lipids (fats).

Micronutrients

Nutrients required by the body in small amounts, consisting of vitamins and minerals.

Energy-Yielding Nutrients

Nutrients that can be metabolized to provide energy to the body, yielding $4\,kcal/g$ for carbohydrates, $4\,kcal/g$ for proteins, and $9\,kcal/g$ for lipids.

Nutrient Density

An evaluation of a food's nutrient content in comparison to the calories it provides, characterizing foods high in nutrients and relatively low in calories.

Energy Density

A measurement of the calorie count of a food in relation to its weight.

Fortified Foods

Foods that have one or more nutrients added during processing that were not originally present.

Enrichment

The process of adding back nutrients that were lost during food processing.

Enriched Grains

Grain products to which specific amounts of thiamine, riboflavin, folic acid, niacin, and iron have been added.

Recommended Dietary Allowances (RDA)

Nutrient intake recommendations calculated to meet the needs of nearly all healthy individuals ($97\text{--}98\%$ of the population) in each gender and life stage group.

Estimated Average Requirement (EAR)

The amount of a nutrient estimated to meet the needs of $50\%$ of individuals in a specific gender and life stage group.

Adequate Intake (AI)

Nutrient intake recommendations established when there is insufficient scientific evidence to set an EAR and calculate an RDA.

Tolerable Upper Intake Level (UL)

The maximum level of daily nutrient intake that is unlikely to pose a risk of adverse health effects or toxicity.

Estimated Energy Requirement (EER)

The average predicted daily energy intake needed to maintain body weight in healthy individuals.

Acceptable Macronutrient Distribution Ranges (AMDR)

Intake ranges for energy-yielding nutrients expressed as percentages of total daily energy intake: $45\text{--}65\%$ for carbohydrates, $10\text{--}35\%$ for proteins, and $20\text{--}35\%$ for lipids.

Health Claims

Statements on food labels that characterize the relationship between a food substance and a disease or health-related condition, requiring FDA authorization.

Structure-Function Claims

Statements on food labels describing how a product affects body structure or function without referring to a specific disease, which do not require FDA authorization.

Nutrient Content Claims

Statements on food labels characterizing the level of a nutrient in a food, such as 'fat free' or 'reduced sodium'.

Registered Dietitian

A credentialed medical nutrition professional who has earned a bachelor's degree, completed $1200+$ hours of supervised practice, passed a CDR national exam, and holds a protected title.

Nutritionist

An unprotected title for individuals advising on nutrition without standardized educational, examination, or regulatory requirements.

Digestion

The process of breaking food down into components small enough to be absorbed by the body.

Absorption

The process of taking digested substances into the interior of the body and blood supply.

Gastrointestinal Tract (GI Tract)

A hollow tube consisting of the mouth, pharynx, esophagus, stomach, small intestine, and large intestine where digestion and absorption occur.

Accessory Organs

Digestive system structures—specifically the salivary glands, liver, gallbladder, and pancreas—that produce or store secretions to aid digestion.

Lumen

The inside space of a tubular organ structure.

Mucosa

The innermost layer of epithelial tissue lining the GI tract that serves as a protective barrier and participates in digestion and absorption.

Transit Time

The total amount of time required for food and its waste products to pass through the GI tract from mouth to anus, normally $24\text{--}72\text{ hours}$ in a healthy adult.

Mucus

A fluid secretion that moistens, lubricates, and protects the digestive tract lining.

Enzymes

Protein molecules that accelerate the rate of chemical reactions without being changed themselves during the process.

Salivary Amylase

An enzyme in saliva that begins the enzymatic digestion of carbohydrates by breaking long chains of starches into shorter sugar chains.

Bolus

A round mass of chewed food mixed with saliva that is swallowed down the pharynx.

Pharynx

A funnel-shaped opening connecting the nasal passages and mouth to the respiratory passages and esophagus, responsible for swallowing.

Epiglottis

A valve that covers the opening to the lungs during swallowing to prevent food from entering the passageway to the lungs.

Peristalsis

Rhythmic, wave-like smooth muscle contractions that propel food forward through the digestive system from beginning to end.

Sphincter

A circular muscular valve that controls the flow of materials between sections of the GI tract.

Chyme

A semiliquid mixture formed in the stomach when swallowed food boluses are churned with highly acidic stomach secretions.

Gastrin

A hormone secreted by the stomach that stimulates gastric juice secretion and increases stomach motility.

Pepsinogen

An inactive protein-digesting enzyme produced by the gastric glands in the stomach.

Pepsin

The active protein-digesting enzyme in the stomach created when pepsinogen is activated by hydrochloric acid.

Peptic Ulcer

A sore on the lining of the stomach, small intestine, or esophagus, most commonly caused by Helicobacter pylori infection.

Pyloric Sphincter

The muscular sphincter that regulates the rate at which chyme moves out of the stomach and into the small intestine.

Duodenum

The first part of the small intestine and the primary site where most chemical digestion occurs.

Jejunum

The middle section of the small intestine, serving as the site where most nutrient absorption occurs.

Ileum

The final section of the small intestine involved in nutrient absorption prior to waste passing into the large intestine.

Segmentation

Rhythmic local constrictions of the small intestine that move chyme back and forth to mix it and increase contact with the intestinal wall.

Villi

Finger-like protrusions on the lining of the small intestine that increase surface area to aid digestion and absorption.

Microvilli (Brush Border)

Small brush-like projections on the mucosal cell membrane that expand the absorptive surface area of the small intestine and contain digestive enzymes.

Lacteal

Specialized lymphatic vessels located in the small intestine that absorb digested fats.

Bile

A digestive fluid produced in the liver and stored in the gallbladder that is released to aid in fat digestion and absorption.

Cholecystokinin

A hormone that stimulates contraction of the gallbladder to expel bile into the small intestine.

Intestinal Microbiota

Microorganisms (predominantly bacteria) residing in the GI tract that act on unabsorbed food, producing B vitamins, Vitamin K, and short-chain fatty acids.

Prebiotic

A non-digestible food ingredient (such as dietary fiber) that feeds beneficial gut bacteria and promotes a healthy microbiota.

Probiotics

Live bacteria (such as Lactobacillus) consumed to inhibit the growth of harmful bacteria and maintain microflora balance.

Enteral Feeding

An alternative feeding method delivering liquid nourishment directly into the GI tract via a tube.

Parenteral Feeding

An alternative feeding method delivering nutrients (amino acids, carbohydrates, lipids) directly into the veins when the GI tract cannot be used.