Nutrition and Dietary Reference Intakes Quiz

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Questions and Answers

What is the primary purpose of Dietary Reference Intakes (DRIs)?

To outline the history of dietary practices

To establish regulations for food industries

To provide a scientific framework for developing food guides (correct)

To support the marketing of specific dietary supplements

Which food group is NOT part of the four major food groups outlined for meeting nutritional needs?

Meats and Alternatives (correct)

Grains

Dairy or Alternatives

Fruits and Vegetables

What does the RDA (Recommended Dietary Allowance) ensure?

It meets the needs of 98% of the population. (correct)

It defines the maximum nutrient intake to avoid toxicity.

It covers the needs of only a small fraction of the population.

It satisfies the nutrient needs of 50% of the population.

How are the Dietary Reference Intakes (DRIs) and Dietary Reference Values (DRVs) different?

DRIs are co-developed in the US and Canada, while DRVs are used in the UK. Signup and view all the answers

What is the main goal of following food guides?

To meet nutrient needs and prevent deficiencies Signup and view all the answers

What is the focus of updated Dietary Reference Intakes (DRIs) in modern times?

Preventing chronic diet-related diseases Signup and view all the answers

What does the Estimated Average Requirement (EAR) ensure?

It covers the nutrient needs of half the population. Signup and view all the answers

What is the primary rationale behind categorizing food into four major groups?

To ensure balanced intake of essential nutrients Signup and view all the answers

What is chyme primarily composed of?

Partially digested food, stomach acids, and enzymes Signup and view all the answers

Which structure in the small intestine increases the surface area for nutrient absorption?

Villi and microvilli Signup and view all the answers

How are fat-soluble nutrients transported in the body after absorption?

Through lymphatic vessels Signup and view all the answers

What role does the hepatic portal vein play in nutrient distribution?

It transports nutrients to the liver for processing. Signup and view all the answers

What benefit can soluble fiber provide to the body?

Lowers cholesterol and aids in disease prevention Signup and view all the answers

Which type of carbohydrate is most linked to an increase in blood sugar levels?

Amylopectin Signup and view all the answers

What common digestive issue results from lactose intolerance?

Abdominal cramps Signup and view all the answers

What mechanism helps regulate blood glucose levels when they drop?

Glucagon release from the pancreas Signup and view all the answers

What are probiotics?

Live bacterial cultures found in certain foods Signup and view all the answers

What percentage of total daily calories from carbohydrates is recommended?

45-65% Signup and view all the answers

Which type of blood vessel is associated with nutrient exchange?

Capillaries Signup and view all the answers

What substance is primarily stored as glycogen in the body?

Glucose Signup and view all the answers

Which type of carbohydrate is associated with a quick energy release?

Glucose Signup and view all the answers

Which vitamin can help in regulating blood sugar levels?

B vitamins Signup and view all the answers

What condition can result from sodium deficiency?

Hyponatremia Signup and view all the answers

Which nutrient is primarily necessary for oxygen transport in the blood?

Iron Signup and view all the answers

What is a consequence of iodine deficiency?

Goiter Signup and view all the answers

Which mineral is important for immune function, wound healing, and protein synthesis?

Zinc Signup and view all the answers

How is water primarily distributed in the human body?

About 2/3 intracellular and 1/3 extracellular Signup and view all the answers

What role do electrolytes play in the body?

They help maintain water balance. Signup and view all the answers

How many lifestages do women have compared to men due to pregnancy and lactation?

16 Signup and view all the answers

What is the primary function of the kidneys in water regulation?

Filtering blood and adjusting fluid volume Signup and view all the answers

What is the main contributor to daily energy expenditure?

Basal Metabolic Rate (BMR) Signup and view all the answers

What is the AI for sodium intake per day?

1500 mg Signup and view all the answers

What is the largest contributor to energy expenditure in the body?

Basal metabolism Signup and view all the answers

Which type of metabolism involves building molecules and requires energy?

Anabolic metabolism Signup and view all the answers

What percentage of energy intake is recommended for carbohydrates according to AMDRs?

45-65% Signup and view all the answers

What is the function of ATP in the cell?

It stores energy for cellular functions. Signup and view all the answers

Which of the following best defines the Thrifty Gene Theory?

Fetal nutrition and early-life circumstances can predispose individuals to obesity. Signup and view all the answers

Which group primarily uses DRIs to plan and assess diets?

Registered Dietitians Signup and view all the answers

Which of the following methods does NOT contribute to food preservation?

Boiling Signup and view all the answers

What organization regulates dietitians in Quebec?

Ordre professionnel des diététistes du Québec Signup and view all the answers

What can excessive intake of iron lead to when associated with genetic disorders?

Hemochromatosis Signup and view all the answers

What is the primary role of water in metabolism?

To transport nutrients and eliminate waste Signup and view all the answers

What is the primary source of selenium in the diet?

Brazil nuts Signup and view all the answers

What core nutrients are included in the Nutrition Facts Table?

Calcium, Iron, Sodium Signup and view all the answers

Which of the following pathogens is known to cause foodborne illnesses?

Salmonella Signup and view all the answers

What outcome is associated with potassium deficiency?

Heart problems Signup and view all the answers

Which food group includes legumes as alternatives?

Meat & Alternatives Signup and view all the answers

What is the pH scale used for?

Assessing acidity or alkalinity Signup and view all the answers

Which agency is primarily responsible for inspecting food safety in Canada?

Canadian Food Inspection Agency (CFIA) Signup and view all the answers

What is a common long-term health effect of certain foodborne illnesses?

Chronic gut problems Signup and view all the answers

Which type of grain retains all parts including the germ, endosperm, and bran?

Whole Grains Signup and view all the answers

How does the body distribute absorbed nutrients throughout?

Blood Vessels Signup and view all the answers

How does the thermic effect of food contribute to energy expenditure?

It accounts for energy spent on digesting and metabolizing food. Signup and view all the answers

Which nutrients are milk products fortified with in Canada?

Vitamins A and D Signup and view all the answers

What is the most significant factor that influences basal metabolic rate (BMR)?

Genetics Signup and view all the answers

Which of the following describes foodborne intoxication?

Caused by toxins produced by pathogens. Signup and view all the answers

What is the primary role of enzymes in nutrition?

Speeding up chemical reactions Signup and view all the answers

Which range indicates the total fat intake according to AMDRs?

20-35% Signup and view all the answers

Which food preservation method is considered safe despite public concerns?

Irradiation Signup and view all the answers

What is the primary focus of the first part of the food safety lesson?

Risk assessment of foodborne illnesses Signup and view all the answers

What component of the digestive system is responsible for nutrient absorption?

Small Intestine Signup and view all the answers

Which of the following is an epigenetic factor that can affect metabolic processes?

Dietary habits Signup and view all the answers

What percentage of Canadians are estimated to contract a foodborne illness annually?

1 in 8 Signup and view all the answers

What is the primary function of vitamin D?

Increases calcium absorption Signup and view all the answers

Which vitamin is primarily responsible for preventing scurvy?

Vitamin C Signup and view all the answers

What deficiency disease is associated with a lack of thiamin (B1)?

Beriberi Signup and view all the answers

Which mineral is crucial for blood clotting?

Calcium Signup and view all the answers

Which of the following is a source of beta-carotene?

Spinach Signup and view all the answers

Which deficiency is related to vitamin B12?

Pernicious anemia Signup and view all the answers

What is the indestructibility of minerals referring to?

Minerals cannot be created or destroyed. Signup and view all the answers

What is the main role of potassium in the body?

Fluid balance maintenance Signup and view all the answers

Which vitamin supports DNA synthesis and red blood cell production?

Folate Signup and view all the answers

What is the consequence of vitamin K deficiency in newborns?

Bleeding risk Signup and view all the answers

Which fat-soluble vitamin can be synthesized from cholesterol?

Vitamin D Signup and view all the answers

What role does magnesium play in the body?

Energy production Signup and view all the answers

Which vitamin is primarily involved in protecting against oxidative stress?

Vitamin E Signup and view all the answers

Which mineral is part of hydroxyapatite crystals in bones?

Phosphorus Signup and view all the answers

What determines an atom's chemical behavior?

The electrons in its valence shell Signup and view all the answers

Which statement accurately describes covalent bonds?

They involve sharing electrons to fill valence shells. Signup and view all the answers

How do polar molecules behave in water?

They form hydrogen bonds with other polar solutes. Signup and view all the answers

What role do enzymes play in the digestive system?

They facilitate chemical reactions by binding to specific substrates. Signup and view all the answers

Which of the following statements about starch is correct?

Heating starch allows for hydrogen bonding with water. Signup and view all the answers

What typically happens to the pH level in the stomach?

It fluctuates but generally stays close to pH 1. Signup and view all the answers

In the context of hydrogen ions, how do they affect protein structures?

They disrupt hydrogen bonds, leading to protein denaturation. Signup and view all the answers

What is the primary function of mucus in the digestive system?

To ease food passage and protect tissues. Signup and view all the answers

What is a characteristic of non-polar molecules like lipids in water?

They do not dissolve in water. Signup and view all the answers

Which organ is not part of the digestive tract?

Pancreas Signup and view all the answers

What happens during mechanical digestion?

Food is physically broken down into smaller pieces. Signup and view all the answers

What does the pH scale measure?

The concentration of hydrogen ions in a solution. Signup and view all the answers

What best describes an aqueous solution?

A mixture where the solvent is primarily water. Signup and view all the answers

What is the impact of poor diet on protein synthesis?

It halts protein synthesis if essential amino acids are missing. Signup and view all the answers

What are the two types of nitrogen balance with regard to health status?

Negative and Positive balance Signup and view all the answers

Which of the following statements about fat-soluble vitamins is correct?

They may accumulate to toxic levels if taken excessively. Signup and view all the answers

What is a key characteristic of proteins regarding their structure?

They fold into specific 3D shapes that determine function. Signup and view all the answers

How are amino acids absorbed in the body after digestion?

Via the hepatic portal vein after passing through the liver. Signup and view all the answers

Which of the following describes the process of protein denaturation?

It can occur due to changes in temperature or pH. Signup and view all the answers

What are the consequences of vitamin deficiencies?

They may cause reversible tissue damage. Signup and view all the answers

How are high-quality proteins characterized?

They provide all 9 essential amino acids. Signup and view all the answers

What is the role of insulin as a protein-based hormone?

It regulates blood sugar levels. Signup and view all the answers

Which food combination is an example of protein complementation?

Rice and beans. Signup and view all the answers

What exacerbates the risk of protein allergies?

Exposure to common allergens like nuts and shellfish. Signup and view all the answers

Which of the following vitamins is categorized as water-soluble?

Vitamin C Signup and view all the answers

What occurs during protein turnover?

Proteins are recycled into amino acids for new use. Signup and view all the answers

What can be a deficiency consequence of Vitamin A?

Night blindness Signup and view all the answers

What is a consequence of excessive intake of simple carbohydrates?

Chronic diseases like type 2 diabetes Signup and view all the answers

What is the primary function of lipids in cooking?

Contribute to flavor and texture Signup and view all the answers

Which type of fatty acid has no double bonds between carbon atoms?

Saturated fatty acids Signup and view all the answers

What is the role of chylomicrons in lipid transport?

Transport dietary triglycerides from the intestines Signup and view all the answers

Which fatty acid type is particularly important for brain health?

Omega-3 fatty acids Signup and view all the answers

How is visceral fat different from subcutaneous fat?

Visceral fat protects internal organs, while subcutaneous fat cushions the body. Signup and view all the answers

What percentage of total caloric intake is recommended for fats according to the AMDR?

20-35% Signup and view all the answers

Which type of lipoprotein is known as 'bad cholesterol'?

LDL Signup and view all the answers

What dietary change can help reduce LDL cholesterol levels?

Increase soluble fiber intake Signup and view all the answers

What is a role of cholesterol in the body?

Synthesizes hormones like estrogen and testosterone Signup and view all the answers

Which type of fatty acids must be obtained from the diet?

Essential fatty acids (Omega-3 and Omega-6) Signup and view all the answers

What process primarily breaks down triglycerides in the small intestine?

Chemical digestion by bile acids Signup and view all the answers

What is the main health risk associated with excessive LDL cholesterol?

Development of cardiovascular disease (CVD) Signup and view all the answers

Which of the following statements about trans fatty acids is correct?

They are man-made through the process of hydrogenation. Signup and view all the answers

Study Notes

Dietary Reference Intakes (DRIs)

DRIs are reference values for planning and assessing nutrient intakes in healthy people.
They are a scientific basis for food guides and nutritional guidelines.
A daily 90mg vitamin C intake requires 7 servings of fruits and vegetables.
DRIs are co-developed by experts in Canada and the U.S., while the UK uses Dietary Reference Values (DRVs).

Rationale Behind Food Groups

Food groups help meet nutritional needs efficiently.
Recommended servings are based on nutrient requirements for health (scientific research).
Examples include fruits/vegetables, proteins, grains, and dairy/alternatives.
The goal is a balanced intake of vitamins, minerals, and macronutrients.

Food Guides

Food guides help individuals make informed food choices.
Recommendations are based on DRIs or DRVs.
Following guides helps meet nutrient needs, prevent deficiencies, and maintain health.

Scientific Evidence Behind Serving Suggestions

DRIs are based on decades of research.
DRIs get updated with new nutrition research.
Guidelines assist healthy food choices when shopping/planning meals.

History of DRIs

Early DRIs focused on preventing deficiency diseases (e.g., scurvy).
Now, the focus is on preventing chronic diseases (e.g., CVD, type 2 diabetes).

Objectives of DRIs

Prevention of deficiency diseases.
Reduced risk of chronic diet-related diseases.
Establishing safe upper limits for nutrients to avoid toxicity.

Nutrient Intake Standards

Group 1: Focuses on deficiency prevention and safe supplement use.
EAR: Meets the nutrient needs of 50% of the population.
RDA: Meets the needs of 98% of the population.
AI: Used when RDA cannot be determined.
UL: The maximum intake unlikely to cause toxicity.
Group 2: DRIs for energy and macronutrients (carbohydrates, lipids, proteins).

Nutrient Standards by Gender & Life Stage

Men have 10 lifestages, women 16 (due to pregnancy/lactation).
Pregnancy significantly increases nutrient needs (e.g., iron from 8mg to 27mg).

DRIs for Most Nutrients

Sodium AI is 1500 mg/day, but North American average intake is ~3400 mg/day (due to processed foods).

Summary of DRIs

Optimal intake of nutrients lies between RDA and UL on a graph (Nutrient intake on x-axis, Health on y-axis).

DRIs for Energy and Macronutrients

EER calculates energy needs based on activity, height, weight, age, and gender.

Acceptable Macronutrient Distribution Ranges (AMDRs)

Carbohydrates: 45-65% of energy intake.
Fat: 20-35%.
Protein: 10-35%.
These ranges reduce chronic disease risk and ensure adequate energy intake.

Who Uses DRIs?

Registered dietitians frequently use DRIs to assess and plan diets.
General practitioners often refer patients to dietitians.

Becoming a Registered Dietitian

Quebec's dietetics are regulated by the Ordre professionnel des diététistes du Québec (OPDQ).
Dietitians of Canada provides information in other provinces.

Food Industry and DRIs

The Nutrition Facts Table is based on DRIs and regulated by the CFIA.
Mandatory since 2007 in Canada.

Nutrition Facts Table

Contains 13 nutrients (e.g., calcium, iron, sodium).
Daily Values are based on a 2000 kcal diet and represent the percentage proportion by serving.

Grains Food Group

Grains are seeds with a germ, endosperm, and bran.
High in carbohydrates, fiber, folate, vitamin E, magnesium, and iron.
Whole grains contain all parts; refined grains (e.g., white bread) only have endosperm.

Meat & Alternatives Food Group

Meat provides protein, B6/B12, iron, and zinc.
Alternatives include legumes, nuts, and seeds.
Legumes/nuts are energy-dense, rich in nutrients (necessary for developing embryos).

Milk & Alternatives Food Group

Includes milk, cheese, yogurt.
Rich in protein, riboflavin, vitamins D/B12, and calcium.
Milk in Canada has fortification with vitamins A and D.

Vegetables and Fruit Food Group

Includes fruits/vegetables (botanically fruits).
Rich in vitamins, minerals, fiber, antioxidants.
Mushrooms are examples of non-plant members.

Canada’s Food Guide

Simplifies recommendations for different age/gender groups into serving suggestions.
Fruits and vegetables have the most recommended servings.

Fruits & Vegetables: Why So Nutritious?

Rich in vitamins, minerals, fiber, antioxidants.
Designed by nature for animal nourishment and seed dispersal.

Food Designed by Nature

Fruits encourage seed dispersal by attracting animals.
Seeds, eggs, milk provide nourishment for developing organisms.

Introduction to Basic Concepts in Chemistry

Matter: Has mass, occupies space.
Elements: Pure substance of only one type of atom.
Atoms: Smallest unit of an element, retains properties.
Molecules: Two or more atoms bonded together.
Ions: Atoms/molecules with a charge (gained/lost electrons).
Compounds: Different types of atoms bonded together.

Key Chemistry Concepts for Nutrition and Molecular Gastronomy

Solutions: Homogenous mixtures of substances.
Solubility: Ability of a substance to dissolve in a solvent.
Enzymes: Catalyze chemical reactions (essential for digestion).
pH Scale: Measures acidity/alkalinity (0-14, 7 is neutral).

Digestive System

Breaks down food for nutrient absorption.
Involves mouth, esophagus, stomach, small intestine, and large intestine.

Circulatory System

Distributes absorbed nutrients.
Involves blood vessels and the heart.

Periodic Table of Elements

25 elements are essential for life.
Humans have a similar chemical composition to plants (because of consuming plants and foods).

Human Body Composition

Composed of 23+ elements and trillions of atoms.
Earth contains 92 elements and many atoms.

Molecules and Compounds

Molecules: Atoms bonded together in a set arrangement.
Compounds: Molecules made up of different elements.
Oxygen gas is a molecule (but not a compound as it contains only one element).

Atoms and Subatomic Particles

Protons: Positively charged, in the nucleus.
Neutrons: No charge, in the nucleus.
Electrons: Negatively charged, orbit the nucleus.
Valence shell: Outermost shell; determines chemical behavior.
Valence electrons: Electrons in the valence shell; full valence shells make an element inert (no bonds).

Chemical Bonds

Covalent Bonds: Sharing electrons to fill valence shells; strongest bonds (e.g., solid table).
Ionic Bonds: Transferring electrons, creating charged ions; weaker than covalent bonds; dissociate in water (e.g., table salt).

What is a Solution?

An evenly distributed mixture of two or more compounds.
Solvent: Primary component (e.g. water).
Solute: Lesser component dissolved in the solvent (e.g. nutrients in plasma).
Blood plasma is an aqueous solution, carrying nutrients to body cells via capillaries.

Electronegativity

Degree of an atom's attraction for electrons in a bond.
Oxygen is highly electronegative, pulling electrons and creating partial charges.
Hydrogen bonds form between partial positive hydrogen and negative oxygen in polar molecules.

Polar Molecules and Hydrogen Bonds

Polar Molecules: Molecules with partial charges (uneven electron sharing).
Hydrogen Bonds: Weak bonds between polar molecules' partial charges.
Water forms hydrogen bonds with polar molecules, aiding in dissolving them.

Solubility of Solutes

Solubility describes how easily a compound dissolves in a solvent.
Non-polar molecules (like lipids) do not dissolve in water (e.g., oil and water).

Starch Solubility

Starch: Long glucose chains in plant-based foods.
Gelation: Starch swells and unfolds when heated, dissolving.
Binding water molecules thickens mixtures (e.g., sauces).

Cooking and Starch

Pasta water starch forms a glue-like substance due to hydrogen bonding, improving sauce adhesion.

Enzymes

Proteins that speed up chemical reactions (e.g., digesting nutrients).
Specific: bind specific substrates. Lactase binds lactose.
Structure: Maintained by hydrogen bonds (changes in pH affect).

The pH of Fluids

pH measures hydrogen ion concentration, impacting acidity and enzyme function.
Digestive system pH varies (mouth 6.4, stomach 1, small intestine 8) affecting enzyme activity.

The pH Scale

Ranges from 0 (acidic) to 14 (alkaline); Each whole number represents a tenfold change in hydrogen ion concentration.
Impacts bonds: Hydrogen ions disrupt hydrogen bonds, affecting protein/enzyme structures.

Influence of pH on Protein Structure

Adding lemon juice to milk causes curdling by increasing hydrogen ions, disrupting casein proteins and causing aggregation.

Digestive System Overview

Digestive system organs work together, like an assembly line, to digest food and deliver nutrients to cells.

Cells, Tissues, and Organs

Cells are the body's basic building blocks.
Tissues are groups of similar cells working together (epithelial, connective, muscle, neural).
Organs are tissues functioning together.
Organ systems are organs working in a coordinated manner.

Types of Tissues in the Digestive System

Epithelial tissue lines the digestive tract, absorbs nutrients, and secretes enzymes.
Connective, muscle, and nervous tissue assist in moving food, provide structure, and transmit signals.

Digestive Organ System Components

Main organs: Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus.
Accessory organs: Salivary glands, gallbladder, pancreas, liver.
Lumen: The hollow area in the digestive tract.
Transit time: Food’s time in the digestive tract (24-72 hours).

Functions of the Digestive System

Secretion of enzymes, hormones, and mucus to aid digestion and protect tissues.

The Mouth and Stomach

Mechanical digestion (physical breakdown) and chemical digestion (enzyme breakdown) begin in the mouth.
Stomach churns food, mixing it with acids and enzymes, into chyme.

Small Intestine Architecture

Villi and microvilli increase surface area for nutrient absorption.
Nutrients absorbed by epithelial cells enter blood or lymph vessels.
High cell turnover (malnutrition leads to impaired absorption e.g., diarrhea).

The Digestive System Meets the Circulatory System

Absorption: Nutrients move from the GI tract into blood/lymph vessels.
Water-soluble nutrients move via blood to the liver.
Fats enter lymphatic system to travel to the bloodstream.

Accessory Organs

Liver, gallbladder, pancreas aid digestion by releasing substances into the small intestine.

Nutrient Delivery

Hepatic portal vein delivers absorbed nutrients to the liver before the rest of the body.

Elimination and Gut Flora

Elimination: Solid waste removed.
Gut flora contains 400+ bacterial species that help break down fiber and produce beneficial compounds.
Probiotics provide live bacterial cultures; prebiotics contain fiber to nourish gut bacteria.

The Network of Blood Vessels

Heart pumps blood through the circulatory system.
Blood vessels include arteries, arterioles, capillaries, venules, and veins.

Nutrient Exchange Between Blood and Cells

Capillaries facilitate nutrient/oxygen delivery to cells and waste removal.

Overview of Carbohydrates

Carbohydrates are a significant energy source, impacting health based on type and amount.
Simple/complex carbohydrates differ in their roles.

The Making of Food Calories

Plants store energy as glucose, which we consume for energy.
Carbohydrates/proteins = 4 kcal/g; Lipids = 9 kcal/g.
Calories on labels are kilocalories(kcal), but commonly labeled as "big Calories".

Simple Carbohydrates and Sweeteners

Monosaccharides (glucose, fructose, galactose) are simple sugars, with glucose being most important for the body.
Disaccharides (lactose, maltose, sucrose) are common sugars; sucrose is widely consumed, contributing to excessive sugar intake.
Excessive simple sugars are linked to obesity/type 2 diabetes.
Alternative sweeteners (Stevia, Splenda, sugar alcohols) offer sweetness with fewer calories but can cause digestive issues.

Complex Carbohydrates

Starch: Plants store glucose as starch, broken down to glucose in digestion.
Amylose: Digests slowly, slow rise in blood glucose.
Amylopectin: Digests quickly, fast rise in blood glucose.
Sources: Grains, legumes, and vegetables.
Glycogen: Body’s storage form of glucose in liver/muscles, rapid energy release.
Fiber:
Soluble: Dissolves in water, slows digestion, traps glucose/cholesterol, feeds gut bacteria (prevents diseases).
Insoluble: Adds bulk to stool (promotes healthy bowel movements).

Digestion of Carbohydrates

Enzymes (salivary amylase, pancreatic amylase, maltase, sucrase, lactase) break down carbohydrates.
End products (mainly glucose, some fructose/galactose) are absorbed into the bloodstream and converted to glucose in the liver.
Lactose intolerance: Insufficient lactase results in digestive issues.

Carbohydrates and Disease

Blood glucose regulation: Insulin/glucagon maintain blood glucose levels.
Types of Diabetes:
Type 1: Autoimmune; pancreas doesn't produce insulin.
Type 2: Insulin resistance due to diet/inactivity.
Gestational: Occurs during pregnancy.

Recommendations for Carbohydrate Intake

RDA for glucose: 130g/day for adults (minimum needed).
AMDR for carbohydrates: 45-65% of total calories (approximately 225-325g for a 2000kcal diet).
Fiber recommendations: 14g fiber per 1000 kcal.

Key Issues with Modern Carbohydrate Intake

Overconsumption of simple sugars from processed foods/sugary drinks is linked to diseases.
Low fiber intake from pulses/vegetables is common.

Lipids

Lipids are important for flavor, texture, nutrient absorption, and satiety.
Fat cells provide organ protection, insulation, and cushioning.

Types of Lipids

Fatty acids are the building blocks; Chain length and saturation affect their properties. Types include:
Saturated fatty acids: Straight chains, solid at room temperature.
Unsaturated fatty acids: Bent chains, liquid at room temperature; Monounsaturated vs. Polyunsaturated.
Omega fatty acids (omega-3/6): Essential for brain health/reducing inflammation; found in fish, walnuts, flaxseeds.
Trans fatty acids: Man-made (hydrogenation); harmful for heart health.

Triglycerides and Phospholipids

Triglycerides: Common form of fat in food/body.
Phospholipids: Similar to triglycerides, have a phosphate group; form cell membranes, act as emulsifiers.

Cholesterol

Cholesterol lacks fatty acids and is not broken down.
Plays a role in cell membranes, vitamin D/hormone synthesis.
Dietary source found in animal products; liver also makes cholesterol.

Digestion and Absorption of Lipids

Digestion starts in mouth/stomach, small intestine is major site.
Bile breaks lipids into micelles.
Pancreatic lipase breaks triglycerides into free fatty acids and monoglycerides.
Short/medium-chain fatty acids are absorbed directly into the bloodstream.
Long-chain fatty acids are packaged into chylomicrons for transport to the bloodstream.

Lipoproteins

Lipoproteins transport lipids through the bloodstream. Types include:
Chylomicrons: Transport triglycerides from intestines.
VLDLs: Transport triglycerides made by the liver to fat cells.
LDLs: Deliver cholesterol to cells ("bad cholesterol").
HDLs: Remove cholesterol from cells ("good cholesterol").

Cardiovascular Disease (CVD)

CVD includes heart and blood vessel diseases, often caused by plaque buildup in arteries.
Factors include high LDL cholesterol, high glucose, tobacco use.
Plaque narrows arteries, increasing risk of heart attacks, strokes, or organ damage.
Reducing CVD risk involves increasing soluble fiber, moderating fat intake, and increasing omega-3s.

Recommendations for Lipid Intake

AMDR for fat: 20-35% of total calories.
Limit saturated fat to less than 10% of calories.
Avoid trans fats.

Proteins

Proteins are complex molecules composed of amino acids.
20 amino acids; 9 essential (must be in diet), 11 nonessential.
Amino acids form polypeptide chains, linked by peptide bonds.
Protein shape is essential for its function.
Protein structures are denatured by environmental changes (e.g., temperature, pH).

Protein Synthesis

Based on DNA instructions, linking amino acids in specific sequences.
DNA is transcribed into mRNA; mRNA directs ribosomes to assemble amino acids into polypeptides.
Protein folding creates functional proteins.

Protein Digestion and Absorption

Protein digestion begins in the stomach by:
Hydrochloric acid (HCl) denaturing proteins.
Pepsin breaking proteins into smaller polypeptides.
Continues in the small intestine with pancreatic enzymes.
Amino acids are absorbed into the bloodstream through the hepatic portal vein.

Protein Turnover and Nitrogen Balance

Protein turnover: Recycling of proteins into amino acids.
Nitrogen balance: Intake equals loss (growth, pregnancy, recovery, positive).
Negative nitrogen balance happens during starvation/trauma.
Proteins can be broken down for energy by removing the amino group.

Protein in Food and DRIs

Protein requirements (EAR, RDA) depend on body weight.
High-quality proteins contain all essential amino acids (e.g., animal proteins).
Low-quality proteins lack some essential amino acids (e.g., plant proteins).
Protein complementation is achieving a full amino acid profile by combining different plant proteins.

Diseases Involving Proteins

Allergies: Immune system reacting to proteins. Common allergens: nuts, shellfish, milk, eggs, wheat.
Celiac disease: Autoimmune response to gluten; damages intestinal lining.
NCGS (Non-Celiac Gluten Sensitivity): Symptoms like celiac but without intestinal damage.

Vitamins

Vitamins are non-energy-yielding micronutrients, essential for chemical reactions.
- Fat-soluble: A, D, E, K (stored in the body).
- Water-soluble: B complex, C (not stored).

Fat-Soluble Vitamins

Vitamin A: Maintains cell and corneal health, vision. Sources: animal/plant.
Vitamin D: Essential for bone health, supports cell growth. Sources: Sun/fortified foods.
Vitamin E: Protects cells from damage (antioxidant). Sources: Vegetable oils, nuts, seeds.
Vitamin K: Needed for blood clotting, bone health. Sources: Leafy greens, bacteria.

Water-Soluble Vitamins

B Vitamins: Act as coenzymes in energy metabolism/DNA synthesis. Types include Thiamin (B1), Riboflavin (B2), Niacin (B3), Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin.
- Folate: Crucial for cell function, preventing neural tube defects.
- Vitamin B12: Essential for nerve cell maintenance.
- Can be deficient due to lack of intrinsic factor.
Vitamin C: Crucial for collagen formation, an antioxidant.
- Scurvy causes weakened tissues, loose teeth, poor wound healing.

Minerals

Essential elements, major (large amounts) and smaller amounts required (trace minerals).
- Calcium: Needed for bones, teeth, muscle function, clotting.
- Phosphorus: Essential in bone and tooth formation, energy production.
- Magnesium: Important for bone health, muscle function, nerve transmission, energy production.
- Sodium/Potassium: Fluid balance, nerve transmission, muscle function.
- Iron: Essential for oxygen transport (hemoglobin).
- Iodine: For thyroid hormone production (metabolism).
- Zinc: Crucial for immune function, wound healing, protein synthesis.
- Selenium: Antioxidant, immune support.
- Copper: Involved in iron metabolism, collagen, energy production.

Water, Metabolism, and Energy

Water is vital for life, functioning in transport, temperature regulation, and waste elimination.
Osmosis: Water movement across membranes, balancing solute concentrations.
Kidneys: Filter blood, regulate water output.
Metabolism: Sum of body's chemical reactions to produce energy.
- Anabolic: Building molecules.
- Catabolic: Breaking down molecules.
Basal Metabolic Rate (BMR): Measure of resting energy expenditure (breathing, circulation).
ATP (adenosine triphosphate): Energy currency in cells.
Cellular respiration generates ATP from nutrients.
Energy balance maintains a stable weight (calories in = calories out).

Food Safety and Sustainability

Food safety focuses on reducing foodborne illness.
Pathogens (e.g., bacteria, viruses) cause foodborne illnesses from food or via toxins.
Food preservation helps reduce food contamination risks (pasteurization, canning, refrigeration, freezing, irradiation).
Key agencies (Health Canada, CFIA, PHAC) ensure food safety.

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Description

Test your knowledge on Dietary Reference Intakes (DRIs) and their role in nutrition. This quiz covers the major food groups, Recommended Dietary Allowances (RDAs), Estimated Average Requirements (EARs), and the goals of food guides. Challenge yourself to understand the importance and classification of nutritional needs.