Chapter 1 - Science of Nutrition
Page 1: Introduction
Course Information: NUTR 251: Introductory Principles of Nutrition.
Institution Details: The Pennsylvania State University, College of Health and Human Development, Nutritional Sciences.
Theme: "OUR SCIENCE, YOUR HEALTH" emphasizing the commitment to nutritional science.
Page 2: Learning Objectives
Define Key Terms: Nutrition, carbohydrates, proteins, lipids (fats and oils), vitamins, minerals, water, and kilocalories (kcals).
Energy Content Calculation: Use physiological fuel values of energy-yielding nutrients to determine energy content.
Food Choices Factors: Describe factors that influence food choices.
Nutritional Assessment: Discuss components and limitations of nutritional assessment.
Nutrition Information Sources: Identify reliable sources of nutrition information.
Page 3: Importance of Nutrition
Nutritional Impact on Health:
Key statistics show that various causes of death are affected by dietary choices.
Notable diseases influenced by nutrition include:
Heart disease
Cancer
Stroke
Diabetes
Obesity
Dietary role: Certain conditions can be influenced by dietary habits, emphasizing the importance of good nutrition.
Page 4: Nutrition and Disease Associations
Cancer and Diet:
Different types of cancer linked with dietary factors including:
Breast cancer
Liver disease (alcohol)
Colon cancer (dietary fat, fiber)
Prostate cancer (saturated fat)
Overall Dietary Impact: Demonstrates how dietary constituents can affect health outcomes related to various diseases.
Page 5: Dietary Intakes vs. Recommendations
Graphical Data: Shows the percentage of the U.S. population age 1 and above concerning dietary goals:
Categories include vegetables, fruits, grains, dairy, protein foods, added sugars, and fats.
Highlights the disparity between actual intake and recommended levels.
Page 6: Learning Objective 1
Definition of Key Nutritional Terms:
Terms include nutrition, carbohydrates, proteins, lipids, vitamins, minerals, water, and kcals.
Page 7: Nutrition Overview
Definition of Nutrition:
The science of food, nutrients, their actions, interactions, and balance in relation to health and disease; includes ingestion, digestion, absorption, transport, utilization, and excretion of food substances.
Page 8: Essential Nutrients
Characteristics of Essential Nutrients:
Specific biological function.
Absence leads to decline in biological function.
Restoration of normal function possible if the nutrient is added back before permanent damage.
Page 9: Functional Categories of Nutrients
Nutritional Functions:
Energy Provision: Carbohydrates, proteins, fats.
Growth and Development: Proteins, lipids, vitamins.
Body Functions Regulation: Proteins, some lipids, vitamins, minerals, and water.
Page 10: Functional Categories Breakdown
Nutrient Functional Categories:
Provides Energy: Carbohydrates, proteins, lipids.
Promotes Growth: Proteins, lipids, water, some vitamins.
Regulates Body Processes: Proteins, lipids, vitamins, minerals, water.
Page 11: Nutrient Types
Macronutrients: Include carbohydrates, lipids, proteins, and water.
Micronutrients: Consist of vitamins and minerals.
Page 12: Carbohydrates
Chemical Composition: Composed of carbon, hydrogen, and oxygen.
Sources: Fruits, vegetables, grains, and beans.
Energy Content: Provides 4 kcal/g.
Types:
Simple Carbohydrates: Includes table sugar (sucrose), blood glucose.
Complex Carbohydrates: Includes starch, glycogen, and fiber.
Page 13: Lipids
Composition: Composed of carbon, oxygen, and hydrogen; insoluble in water.
Energy Content: Provides 9 kcal/g.
Types: Solid fats and liquid oils.
Page 14: Triglycerides
Main Form of Fat: Composed of three fatty acids attached to a glycerol backbone, serving as a major energy source for the body.
Page 15: Saturated vs. Unsaturated Fats
Saturated Fats:
Solid at room temperature, primarily from animal sources, can raise cholesterol levels.
Unsaturated Fats:
Liquid at room temperature, primarily from plant sources, considered healthier.
Page 16: Essential Fatty Acids
Definition: Unsaturated fatty acids that must be supplied by the diet, e.g., linoleic acid, alpha-linolenic acid.
Functions in Body: Structural components of cell walls, regulation of blood pressure, and nerve transmission.
Page 17: Proteins
Composition: Composed of carbon, oxygen, hydrogen, and nitrogen; main structural components in the body.
Energy Content: Provides 4 kcal/g; formed by peptide bonds between amino acids.
Page 18: Vitamins
Function: Enable chemical reactions; divided into two groups:
Fat-Soluble Vitamins: A, D, E, K (can cause toxicity accumulation).
Water-Soluble Vitamins: C and B-vitamins (destroyed by cooking and excreted from the body).
Page 19: Minerals
Definition: Inorganic substances that cannot be destroyed by cooking; necessary mineral categories:
Major Minerals: Needed in gram amounts daily.
Trace Minerals: Needed in less than 100 mg daily.
Page 20: Water
Importance: Needed in the largest quantity for various vital functions, including:
Solvent and lubricant
Nutrient transport
Body temperature regulation
Sources: Food, drink, and metabolic byproduct.
Page 21: Phytochemicals
Definition: Physiologically active compounds found in plants that may provide health benefits; various examples listed in a table format with food sources.
Page 22: Learning Objective 2
Calculate Energy Content: Use physiological fuel values to determine kcal in food or diet.
Page 23: Energy Sources
Energy Provision: Provided by carbohydrates, proteins, fats, and alcohol (though alcohol is not a nutrient).
Definition of Calorie: The amount of heat energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.
Page 24: Energy Units
Kilocalorie Defined:40 Amount of heat needed to raise the temperature of 1000 grams of water by 1 degree Celsius; more suitable unit for food energy.
Page 25: Physiological Fuel Values
Nutrient Energy Values:
Carbohydrates: 4 kcal/g
Proteins: 4 kcal/g
Fats: 9 kcal/g
Alcohol: 7 kcal/g
Page 26: Calculating Energy from Food
Example Calculation: For 1 slice of bread with peanut butter:
Carbohydrates: 16g CHO x 4 kcal/g = 64 kcal
Proteins: 7g PRO x 4 kcal/g = 28 kcal
Fats: 9g FAT x 9 kcal/g = 81 kcal
Total Energy: 64 + 28 + 81 = 173 kcal.
Page 27: Energy Source Calculation Example
Example Foods: Calculation of kcal from foods like a hamburger and Piña Colada; details energy sources for each macronutrient.
Page 28: Learning Objective 3
Factors Influencing Food Choices.
Page 29: Food Choices Influences
Hunger vs. Appetite:
Hunger: Physical need for food.
Appetite: Psychological desire to eat.
Page 30: Influences on Food Choices
Factors Include:
Psychological needs
Flavor, texture, appearance preferences
Availability, marketing, health knowledge
Social factors, cost, education, and lifestyle habits.
Page 31: Learning Objective 4
Components of Nutritional Assessment.
Page 32: Importance of Reliable Information
Conditions:
Undernutrition: Results from inadequacies in diet.
Overnutrition: Overconsumption leading to obesity and related health issues.
Page 33: Nutritional Status Assessment
Types:
Anthropometric
Biochemical
Clinical
Dietary
Environmental
Page 34: Learning Objective 5
Identifying Reliable Nutrition Information Sources.
Page 35: Scientific Research in Nutrition
Foundation of Nutrition: Established through the scientific method and research.
Page 36: The Scientific Method
Process Overview: Observations lead to questions, hypothesis generation, research experiments, peer review, and subsequent studies.
Page 37: Laboratory Animal Experiments
Usage Justification: When direct human testing isn't possible; subject to ethical guidelines.
Page 38: Human Experiments
Research Approval: Must be approved by a research review board for ethical standards.
Page 39: Human Experimentation Approaches
Methodologies: Include cohort studies, case control, and double-blind studies to minimize bias.
Page 40: Case-Control Studies
Definition: Compare individuals with a condition (cases) to those without (controls); limitations in causality claims.
Page 41: Double-Blind Study Methodology
Advantages: Experimental and control groups with unknown assignments reduce bias.
Page 42: Features of Double-Blind Studies
Bias Reduction:
Neither participants nor researchers know group assignments.
Prevents placebo effects where possible.
Page 43: Peer Review Process
Purpose: Ensures unbiased findings are published in reputable journals.
Page 44: Peer-Reviewed Journals
Importance: Published findings in established journals provide validated nutrition information.
Page 45: Follow-Up Studies
Evidence Validation: Multiple studies necessary to support a hypothesis convincingly.
Page 46: Systematic Reviews
Function: Evaluate and synthesize research on specific topics; examples of important organizations provided.
Page 47: Regulatory Agencies
Key Agencies: FDA (Food and Drug Administration) and FTC (Federal Trade Commission) oversee nutrition marketplaces through regulations.
Page 48: Nutrition Quackery Evaluation
Evaluative Steps: Apply principles of nutrition, examine author qualifications, check for scientific evidence to assess claims.
Page 49: Common Nutrition Myths
Examples of Myths & Fallacies: Addresses misconceptions like cleansing diets, gluten exclusion, and organic necessity.
Page 50: Tips for Spotting Myths
Guidelines: If a claim seems too good to be true, investigate author credentials and research replicability.
Page 51: RDN vs. Nutritionist
Credential Distinction: RDN is a protected title, indicating a registered dietitian; nutritionist definitions vary.
Page 52: Key Points
Macronutrients and Micronutrients: Definitions and distinctions.
Nutritional Deficiency: Subclinical and overt levels.
Nutrition Assessment Types: ABCDE method for assessments.
Peer-Reviewed Information: Essential for credible nutrition knowledge.
Regulation of Supplements: Noted limitations and agency responsibilities.