Comprehensive Study Notes: Foundations of Nutrition (Chapters 1–3)

Chapter 1: An Overview of Nutrition

Key Definitions and Concepts

• Nutrient: A chemical substance in food that supports growth, maintenance, and repair of body tissues. Example: Carbohydrates, proteins, fats, vitamins, minerals, and water.

• Organic (in nutrition/chemistry): Compounds containing carbon. In nutrition, organic nutrients include carbohydrates, lipids, proteins, and vitamins.

• Inorganic (in nutrition/chemistry): Substances not containing carbon. In nutrition, minerals and water are inorganic nutrients.

• Essential nutrient: Nutrients the body cannot synthesize in sufficient quantities and must be obtained from the diet. Example: Essential amino acids, essential fatty acids.

• Energy: The capacity to do work, measured in calories (kcal) in nutrition.

• Energy-yielding nutrients: Nutrients that provide energy when metabolized: carbohydrates, proteins, and fats.

• Calories: Units of energy; specifically, the amount of heat needed to raise 1 kg of water by 1°C. In nutrition, "calorie" usually refers to kilocalorie (kcal).

• Phytochemicals: Non-nutrient compounds in plants that may have health benefits. Example: Flavonoids in berries.

• Energy density: The amount of energy (kcal) per gram of food.

• Nutrient density: The amount of nutrients per calorie of food.

• Micronutrients: Nutrients required in small amounts. List: Vitamins and minerals.

• Macronutrients: Nutrients required in large amounts. List: Carbohydrates, proteins, and fats.

• Vitamins: Organic, essential micronutrients needed for regulation of body processes.

• Minerals: Inorganic, essential micronutrients involved in body structure and regulation.

• Science of nutrition: The study of nutrients in food and their actions in the body.

Scientific Methods in Nutrition

• Control group: The group in an experiment that does not receive the treatment; used for comparison.

• Correlation: A relationship between two variables; does not imply causation.

• Double-blind experiment: Both subjects and researchers do not know who receives the treatment or placebo.

• Experimental group: The group receiving the treatment in an experiment.

• Placebo: An inactive substance given to the control group.

• Variables: Factors that can change in an experiment.

• Experimental studies: Research involving intervention and control groups to test cause and effect.

• Epidemiological studies: Observational studies examining patterns, causes, and effects in populations.

Dietary Reference Intakes (DRIs)

• Dietary Reference Intake (DRI): A set of nutrient intake values for healthy people in the U.S. and Canada.

• Estimated Average Requirement (EAR): Average daily nutrient intake estimated to meet the needs of half the healthy individuals in a group.

• Recommended Dietary Allowance (RDA): Average daily intake sufficient for nearly all (97–98%) healthy individuals.

• Adequate Intake (AI): Established when evidence is insufficient for an RDA; a recommended average intake level.

• Tolerable Upper Intake Level (UL): Maximum daily intake unlikely to cause adverse health effects.

• Estimated Energy Requirement (EER): Average dietary energy intake predicted to maintain energy balance.

• Acceptable Macronutrient Distribution Ranges (AMDR): Ranges of intake for energy-yielding nutrients to reduce risk of chronic disease.

  • Carbohydrates: 45–65% of total kcal

  • Fat: 20–35% of total kcal

  • Protein: 10–35% of total kcal

Nutrition Assessment

• Anthropometric: Measurement of body size, weight, and proportions. Example: BMI, waist circumference.

• Laboratory Tests: Analysis of blood, urine, or tissue samples to assess nutrient status.

• Historical Information: Review of medical, dietary, and social history.

Malnutrition and Health

• Malnutrition: Any condition caused by excess or deficient food energy or nutrient intake.

• Undernutrition: Deficiency of energy or nutrients.

• Overnutrition: Excess of energy or nutrients.

Food Choices and Influences

• Areas influencing food choices include: personal preference, habit, ethnic heritage, social interactions, availability, convenience, economy, positive and negative associations, emotions, values, body weight and image, nutrition and health benefits.

• Most influential: Taste/personal preference.

Energy Values of Macronutrients

• Fat: 9 kcal/g

• Protein: 4 kcal/g

• Carbohydrate: 4 kcal/g

• Most energy-dense: Fat

Macronutrient and Micronutrient Table

Nutrient	Organic or Inorganic?	Energy Yielding?	Macronutrient or Micronutrient?
Carbohydrate	Organic	Yes	Macronutrient
Fat	Organic	Yes	Macronutrient
Protein	Organic	Yes	Macronutrient
Vitamins	Organic	No	Micronutrient
Minerals	Inorganic	No	Micronutrient
Water	Inorganic	No	Macronutrient

Calculating Calories from Macronutrients

• To calculate total calories: Multiply grams of each macronutrient by its kcal/g value and sum.

• To calculate percent calories from each macronutrient:

  • Percent = (kcal from nutrient / total kcal) × 100

Experimental vs. Epidemiological Studies

• Experimental studies: Involve intervention (e.g., clinical trials). Advantages: Can establish causality. Disadvantages: May not reflect real-world conditions.

• Epidemiological studies: Observe populations (e.g., cohort, case-control studies). Advantages: Can identify associations. Disadvantages: Cannot prove causation.

Reliable Nutrition Information

• Tips for evaluating sources:

  • Check credentials of the author (e.g., RDN).

  • Look for references to scientific studies.

  • Be wary of sensational claims or products for sale.

Chapter 2: Planning a Healthy Diet

Key Terms and Principles

• Eating pattern: The combination of foods and beverages that constitute an individual's complete dietary intake over time.

• Calorie control: Managing energy intake to maintain a healthy body weight.

• Adequacy: Providing all essential nutrients, fiber, and energy in sufficient amounts.

• Balance: Consuming the right proportions of foods from each food group.

• Moderation: Avoiding excess intake of any food or nutrient.

• Variety: Including different foods from all food groups.

• Solid fats: Fats that are solid at room temperature, often high in saturated fats.

• Added sugars: Sugars added during processing or preparation.

• Empty calorie foods: Foods high in calories but low in nutrients.

• Sustainable diets: Diets with low environmental impact that contribute to food and nutrition security.

Food Group Plans and MyPlate

• Food group plans: Diet planning tools that sort foods into groups based on nutrient content.

• Legumes: Plants in the bean and pea family; good sources of protein and fiber.

• MyPlate: A visual guide to healthy eating, dividing the plate into fruits, vegetables, grains, protein, and dairy.

• Healthy Eating Index: A measure of diet quality based on conformance to federal dietary guidance.

Grains and Labeling

• Fortified: Nutrients added to foods that were not originally present.

• Enriched: Nutrients added back to foods that were lost during processing.

• Whole grain: Contains the entire grain kernel (bran, germ, and endosperm).

• Refined: Grains that have been milled to remove bran and germ, losing nutrients.

• Bran: The outer layer of a grain, rich in fiber.

• Germ: The nutrient-rich core of a grain.

Food Labels and Claims

• Daily Value (DV): Reference values for nutrients on food labels.

• Percent Daily Value (%DV): Shows how much a nutrient in a serving of food contributes to a daily diet.

• Nutrition Facts Panel: Label on packaged foods showing nutrient content.

• Nutrient Claims: Statements about the amount of a nutrient in a food (e.g., "low fat").

• Health Claims: Statements about a food's relationship to a disease or health condition.

• Structure-Function Claims: Statements about how a nutrient affects the structure or function of the body (e.g., "calcium builds strong bones").

• Free, High/Rich, Good source of: Terms defined by the FDA to describe nutrient content.

Key Principles of Healthy Eating

• Adequacy, balance, calorie control, moderation, and variety.

MyPlate Food Groups and Recommendations

• Fruits, vegetables (dark green, red and orange, legumes, starchy, other), grains, protein foods, dairy.

• Key recommendations: Make half your plate fruits and vegetables; choose whole grains; vary protein sources; include low-fat dairy.

Dietary Guidelines for Americans

• Developed by the USDA and HHS.

• Guiding principles: Follow a healthy eating pattern, focus on variety, nutrient density, and amount, limit added sugars, saturated fats, and sodium, shift to healthier choices, support healthy eating for all.

Food Label Requirements

• Must list: serving size, calories, nutrients (total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrate, dietary fiber, total sugars, added sugars, protein, vitamin D, calcium, iron, potassium), and ingredient list.

• Order of ingredients: Listed by weight, from most to least.

• Updated label: Added sugars, updated serving sizes, larger font for calories.

Using the Nutrition Facts Panel

• Compare %DV to choose more nutrient-dense foods.

Reducing Portion Sizes

• Use smaller plates, measure servings, avoid eating from packages, share restaurant portions.

Chapter 3: Digestion, Absorption, and Transport

Key Terms and Processes

• Digestion: The process of breaking down food into absorbable units.

• Digestive system: Organs involved in digestion and absorption of nutrients.

• Absorption: Uptake of nutrients by cells of the GI tract into the blood or lymph.

• Transport: Movement of nutrients through the body via blood or lymph.

• GI Tract: The continuous tube from mouth to anus where digestion and absorption occur.

• Lumen: The inner space of the GI tract.

• Bolus: A mass of chewed food ready to be swallowed.

• Chyme: Semi-liquid mass of partly digested food in the stomach and small intestine.

• Catalyst: Substance that speeds up a chemical reaction without being consumed.

• Enzyme: Protein that acts as a catalyst in biochemical reactions.

• Peristalsis: Wavelike muscular contractions that move food through the GI tract.

• Segmentation: Periodic squeezing of the intestine to mix and move contents.

• pH: Measure of hydrogen ion concentration; acidity or alkalinity.

• Heartburn: Burning sensation in the chest caused by backflow of stomach acid into the esophagus.

Digestive System Anatomy and Function

• Villi: Fingerlike projections in the small intestine that increase surface area for absorption.

• Microvilli: Tiny hairlike projections on villi that further increase surface area.

• Crypt: Glands in the small intestine that secrete intestinal juices.

• Vascular System: Blood vessels that transport nutrients absorbed from the GI tract.

• Lymphatic System: Network that transports fat-soluble nutrients and large particles.

• GI microbiota: Microorganisms living in the GI tract, important for health and digestion.

• Prebiotic: Substances that promote growth of beneficial bacteria in the gut.

• Probiotic: Live microorganisms that confer health benefits when consumed.

• Homeostasis: Maintenance of stable internal conditions.

Digestive Hormones and Regulation

• Hormones: Chemical messengers that regulate body processes.

• Gastrin: Hormone that stimulates secretion of gastric juice.

• Secretin: Hormone that stimulates the pancreas to release bicarbonate-rich juices.

• CCK (Cholecystokinin): Hormone that stimulates the release of bile and pancreatic enzymes.

Digestive Enzymes and Actions

Organ/Gland	Target Organ	Secretion	Action
Salivary glands	Mouth	Saliva (amylase)	Begins carbohydrate digestion
Gastric glands	Stomach	Gastric juice (pepsin, HCl)	Begins protein digestion
Pancreas	Small intestine	Pancreatic juice (enzymes, bicarbonate)	Digests carbohydrates, proteins, fats; neutralizes acid
Intestinal glands	Small intestine	Intestinal enzymes	Digests carbohydrates, proteins, fats

Gallbladder Function

• Function: Stores and concentrates bile produced by the liver; releases bile into the small intestine to aid fat digestion.

• If removed: Bile flows directly from liver to intestine; fat digestion may be less efficient, requiring dietary adjustments.

Absorption and Transport of Nutrients

• Enterocytes: Intestinal cells that absorb nutrients via diffusion, facilitated diffusion, or active transport.

• Transport systems:

  • Water-soluble nutrients and small products of fat digestion enter the vascular (blood) system and travel to the liver via the portal vein.

  • Fat-soluble nutrients and larger fats enter the lymphatic system before reaching the bloodstream.

GI Microbiota and Health

• Gut bacteria aid digestion, synthesize vitamins, and protect against pathogens.

Hormonal Regulation of Digestion

• Gastrin, secretin, and CCK coordinate digestive secretions and motility.

Common GI Problems and Dietary Solutions

• Constipation: Infrequent, difficult bowel movements. Dietary solutions: Increase fiber, fluids, and physical activity.

• Heartburn: Avoid large meals, fatty foods, and lying down after eating.

Example: Digestion of a Food (e.g., Pizza)

• Carbohydrates begin digestion in the mouth (salivary amylase), continue in the small intestine (pancreatic amylase).

• Proteins begin digestion in the stomach (pepsin), continue in the small intestine (pancreatic and intestinal enzymes).

• Fats are emulsified by bile in the small intestine and digested by pancreatic lipase.

Additional info: Academic context and definitions have been expanded for clarity and completeness. Table entries and examples are inferred from standard nutrition textbooks where the original file referenced textbook tables or figures.