NUTR-1100: Introduction to Nutrition

Introduction to Nutrition

• Nutrition explores the relationship between foods/nutrients and health, metabolism, disease, performance, and sport.
• It examines the reasons behind food choices and eating behaviors, emphasizing environmental factors.

The Science of Nutrition

• Recognized as a complex and dynamic field, integrating multiple disciplines:
  • Chemistry
  • Biology
  • Biochemistry
  • Physiology
  • Genomics
  • Epidemiology
  • Medicine
  • Public Health
  • Psychology
  • Sociology
  • Food Science
  • Food Systems
  • Food Policy
  • Gastronomy
  • Culinary Arts

Nutrients

• Nutrients are substances derived from food essential for bodily functions.
• Functions include providing energy, aiding growth, maintaining body structures, and regulating physiological processes.

Nutrient Classification

• Essential nutrients: Required for normal growth and bodily functions, cannot be synthesized by the body.
• Non-essential nutrients: Can be synthesized internally; not required from diet.

Six Classes of Nutrients

• Macronutrients: Needed in large amounts. They include:

  • Carbohydrates: Provides energy, vital for the nervous system and organs.
    • Types: Simple (sugars) and Complex (starches and fiber).
  • Proteins: Composed of amino acids, function as building blocks and perform various roles in the body.
  • Lipids: Include saturated and unsaturated fats, cholesterol, and trans fats, essential for energy storage and metabolic functions.
  • Water: Vital for all bodily processes but does not provide energy.

• Micronutrients: Required in smaller amounts, essential for facilitating numerous bodily functions.

  • Vitamins: Organic compounds necessary for various biochemical processes.
  • Minerals: Inorganic elements that play roles in processes like enzyme function and metabolic regulation.

• Non-nutrient substances: Such as phytochemicals and zoochemicals, which provide additional health benefits beyond basic nutrition.

Healthy Diet Principles

• A sound nutritional approach integrates the understanding of nutrient roles and requirements for optimal health and disease prevention.
• Nutrition plays a critical role in preventing diseases and promoting overall well-being.

Nutrition Research Types

• Interventional studies involve manipulation of variables to observe effects on outcomes.
• Observational studies involve observing and collecting data without altering any variables.

Experimental Evidence vs Observational Evidence vs Anecdotal Evidence

• Experimental evidence provides reliable scientific proof through structured research and experiments.
• Observational evidence observes phenomena without direct manipulation but remains credible.
• Anecdotal evidence consists of personal experiences or testimonies, often misleading.

Causality vs Association

• Causality indicates a direct influence of one factor on another, e.g., smoking causes lung cancer.
• Association refers to a correlation between two variables that are related but do not directly influence each other, e.g., increased ice cream sales and drowning rates due to hot weather.

Micronutrients vs Macronutrients

• Micronutrients include vitamins and minerals essential for various bodily functions.
• Macronutrients consist of carbohydrates, proteins, lipids, and water, required in larger quantities.

Essential vs Non-Essential Nutrients

• Essential nutrients cannot be synthesized by the body and must be obtained from food.
• Non-essential nutrients can be produced by the body and are not required in the diet.

Healthy Diet Characteristics

• Variety: Consume a diverse range of foods across different food groups.
• Balance: Match energy intake with physical activity while choosing nutrient-dense options.
• Moderation: Practice controlled portion sizes and avoid overconsumption.

Nutrient Density

• High nutrient density foods, like vegetables and whole grains, provide more nutrients relative to calories.
• Low nutrient density foods, such as cakes and sodas, offer fewer nutrients relative to calories consumed.

Healthy Eating Guidelines

• Encourage mindfulness in eating habits.
• Promote home cooking and enjoyment of meals with others.

Acceptable Macronutrient Distribution Ranges (AMDR)

• AMDR refers to the percentage range of carbohydrates, proteins, and fats that contribute to a healthy diet.

Dietary Reference Intakes (DRIs)

• DRIs provide guidelines for nutrient intake to support health and prevent deficiencies.

Importance of Food Guides

• Food guides aim to enhance health, ensure adequate nutrient intake, and mitigate nutrition-related diseases.

Canada’s Food Guide 2019

• Promotes healthy eating, focusing on food habits and beverage choices for optimal health.

Beverage Recommendations in Food Guide

• Water should be the primary beverage; unsweetened coffee, tea, and lower-fat milk options are also encouraged.

Food Labels

• Provide important information regarding food composition and marketing strategies.

Label Reading

• Ingredients are listed in descending order based on weight, highlighting the dominant components of the product.

Comparing Products Using Labels

• Consumers can use nutritional information on labels to make informed dietary choices.

Nutrient Claims

• Statements made by manufacturers about the level of nutrients in a food item.

Health Claims

• Claims that link a food, food component, or dietary supplement to reduced risk of a disease or health condition.

Food Safety

• Critical for ensuring health and preventing foodborne illnesses through proper handling and storage practices.

HACCP (Hazard Analysis Critical Control Point)

• A systematic approach to food safety focusing on preventing hazards by:
  • Conducting hazard analysis.
  • Identifying critical control points.
  • Establishing critical limits.
  • Monitoring critical control points.
  • Implementing corrective actions.
  • Maintaining record-keeping practices.
  • Verifying procedures.

Digestive Organs and Functions

• Begins with the mouth (mechanical digestion); salivary amylase starts starch breakdown.
• Moves to the pharynx, down the esophagus via peristalsis.
• Stomach uses pepsin and gastric acid to continue breakdown; lined with mucus for protection.
• Food then enters small intestine with enzymes from the pancreas for further digestion and nutrient absorption.
• Water reabsorption occurs in the large intestine before waste elimination through the anus.

Enzymes

• Enzymes are proteins that lower the activation energy necessary for chemical reactions.

Metabolism

• Metabolism comprises all chemical reactions aiding in life maintenance.
• Catabolism breaks down complex molecules to release energy.
• Anabolism involves synthesizing complex molecules from simpler ones, requiring energy.

Methods of Absorption

• Nutrient absorption occurs through active transport, facilitated diffusion, passive diffusion, and osmosis.

Food Allergens (Priority Allergens)

• Common allergies include eggs, milk, peanuts, fish, tree nuts, soy, wheat, and others.

Allergies vs Intolerances

• Allergies can cause severe reactions affecting the nervous system, while intolerances generally lead to digestive discomfort and are milder.

Preventative Measures for Food Allergies

• Read food labels diligently and avoid cross-contamination.
• Practice proper handwashing techniques.
• Carry an epinephrine auto-injector for severe allergic reactions.