Kin_Nutrition_Slide_1

KIN275 Introduction to Nutrition: Tools of the Trade Study Notes

Module 1 Overview

  • Presenter: Julia Totosy de Zepetnek, PhD

  • Institution: University of Regina (Kinesiology & Health Studies)

  • Topics Covered:

    • Part 1: Nutrition and Health

    • Part 2: Nutrients

    • Part 3: Dietary Standards

    • Part 4: Health Promotion

Part 1: Nutrition and Health

Definition of Nutrition

  • Nutrition:

    • “The science of the actions of foods, nutrients and other substances within the body (including ingestion, digestion, absorption, transport, metabolism, and excretion).”

    • “The social, economic, cultural, and physiological implications of food and eating.” (Whitney, Rolfes, Hammond & Piche, 2013)

    • “Nutrition is a science that studies the interactions between living organisms and the food they consume.” (Smolin, Grosvenor & Gurfinkel, 2015)

Food Consumption Statistics

  • Average: 70,000 meals & 54 tons of food in one lifetime.

  • Approximately 6 years spent eating in total.

Decision-Making in Food Choices

  • Undergraduates make over 200 decisions about what to eat or drink each day (Wansink & Sobal, 2007).

Factors Influencing Food Choices

  • Preferences

  • Education

  • Habits

  • Ethnic heritage or tradition

  • Social interactions

  • Availability and convenience

  • Economic factors

  • Positive and negative associations with food

  • Emotions

  • Values

  • Body mass and image

  • Perceived nutrition and health benefits

  • Age

  • Additional factors (not specified).

Health Considerations Related to Food Choices

  • Importance of:

    • Nutrient intake

    • Weight management

    • Disease prevention

    • Gut health

    • Mental health

    • Energy levels

    • Longevity

Characteristics of a Healthy Diet

  • Based on observations of long-lived individuals (Blue Zones):

    • Stop eating when 80% full

    • Consume the smallest meal of the day in the late afternoon or evening

    • Include mostly plants in the diet, especially beans

    • Eat meat rarely, in small portions (3-4 oz about 5 times a month)

    • Moderate alcohol consumption (1-2 glasses daily).

Evolution of Nutrition Understanding

  • The caveat that nutritional knowledge is ever-evolving.

Changes in Eating Habits Over Time
Past vs. Present Canadian Diet

  • Time spent on food acquisition has changed:

    • Originally, significant time on food preparation with seasonal varieties.

    • Current trends favor convenience and processed foods, less home preparation.

    • Shift from family meals to individual consumption and fast food.

    • Portion sizes have also increased.

Part 2: Nutrients

Classes of Nutrients

  1. Carbohydrates

  2. Lipids (Fats)

  3. Proteins

  4. Water

  5. Vitamins

  6. Minerals

Nutrient Functions

  • Chemical Substances: Substances found in foods that have specific functions in the body.

    • Can be elements (e.g., Iron) or compounds (e.g., Carbohydrates).

Functions of Nutrients

  • Nutrient Examples and Functions:

    • Carbohydrates:

    • Major source of energy and provides fiber.

    • Lipids (Fat):

    • Energy source, component of cell membranes.

    • Proteins:

    • Function in cellular development, growth, and as transporters for energy.

    • Water:

    • Essential for temperature regulation and nutrient transport.

    • Vitamins:

    • Act as co-factors for enzymatic reactions.

    • Minerals:

    • Maintain cell function and volume.

General Functions of Nutrients

  1. Raw Materials

  2. Regulate Metabolic Processes

  3. Source of Energy

Raw Materials

  • Nutrients form and maintain body structure.

  • Fat, protein, and minerals play crucial roles in keeping bones, tissues, and cells functional.

Regulation of Metabolic Processes

  • Vitamins and minerals are key to maintaining homeostasis and supporting metabolic reactions.

  • Water regulates temperature among many other functions.

Nutrient Energy Contribution

  • Only macronutrients (carbohydrates, fats, proteins) provide energy.

  • Energy is essential for maintaining bodily functions and physical work.

Measuring Food Energy

  • Food energy is measured in kilocalories (kcal):

    • 1 kcal = amount of heat required to raise 1 liter of water by 1 degree Celsius.

    • Kilocalories may also be noted as kcal or Cal (1 Cal = 1 kcal).

Bomb Calorimeter

  • Instrument used to measure heat released when food is combusted, providing estimates of potential energy.

  • Heat of combustion values:

    • Carbohydrates: 4.1 kcal/g

    • Lipids: 9.45 kcal/g

    • Proteins: 4.35 kcal/g

    • Alcohol: 6.93 kcal/g

Adjusting Heat of Combustion Values

  • Adjust for digestibility, implying not all ingested nutrients are metabolized.

  • Digestibility Coefficients:

    • Carbohydrates: 0.98

    • Lipids: 0.95

    • Proteins: 0.92

    • Alcohol: 1.00

The Atwater Values

  • Define the energy that can be physiologically released through the oxidation of specific food components.

Part 3: Dietary Standards

Definition and Purpose of Dietary Standards

  • Sets of recommendations for food intake to aid individuals in meeting nutritional needs and chronic disease prevention.

  • Distinction between Recommended Intakes and Required Intakes:

    • Recommendations serve population targets based on sex and age.

Common Examples of Dietary Standards

  • Dietary Reference Intakes (DRI): Focus on nutrients.

  • Canada’s Food Guide: Emphasis on foods and food groups.

  • USDA MyPlate: Focus on food groups.

How DRIs are Determined

  • Normal distribution graphing of nutrient requirements aids in establishing values such as EAR, RDA, AI, UL.

DRI Categories

  1. Estimated Average Requirement (EAR):

    • Daily intake for 50% of the population.

    • Used for evaluating nutrient needs in groups.

  2. Recommended Dietary Allowance (RDA):

    • Intake sufficient for 97.5% of the population.

    • Based on significant scientific evidence.

  3. Adequate Intake (AI):

    • Estimated intake levels assumed sufficient due to lack of sufficient data.

  4. Tolerable Upper Intake Level (UL):

    • Maximum daily intake unlikely to cause adverse health effects.

Using DRIs for Individuals

  • Example calculations for individual nutrient requirement assessments based on EAR, RDA, UL.

Part 4: Health Promotion

Food Labels Overview

  • Defined as any printed/semi-printed information present on food packaging, promoting its sale.

Nutritional Information

  • Nutrition Facts Table (NFT):

    • Presents absolute quantities and percentage of daily value (%DV).

    • %DV indicates levels of nutrients (5% DV or less = low, 15% or more = high).

Front-of-Package Labelling System

  • High-in symbols on foods with elevated sugars, sodium, or fat levels to inform consumers about health risks.

Canada’s Food Guide

  • A practical guide translating DRIs and AMDR into actionable dietary advice for improving health, emphasizing variety and moderation.

  • Highlights key messages such as:

    • Eat a variety of healthy foods each day.

    • Include plenty of vegetables and fruits, protein foods, and whole grains.

    • Make water the drink of choice.