NUTR-120-02 (20363.202501) on 2/6/2025 (Thu)

Midterm Exam Update

• Test option sheets are currently being marked at the computer marking system, operating from 1 PM to 4 PM.

• Some student IDs are still required; without submission, grades cannot be issued.

• Typical corrections (e.g., incomplete erasures, incorrectly marked NZ) may take an afternoon to resolve, delaying grade returns.

• Grades are expected to be available by early next week.

Online Class Exam

• Online students will write their exam on Saturday at 1:00 PM.

• Different exam format from the in-person class.

• A review session will be held on Wednesday, February 12th, from 12:30 to 1:20 in Arts 200. This session will cover the exam questions and is not recorded for privacy reasons.

Discussion Group Week Three

• Discussion topics focus on nutritional supplements, a frequently asked topic in teaching.

• Discussion group leaders are preparing materials on key messages about vitamins and nutrient claims.

• Helpful evidence-based references will be available through the Student Activity Sheet.

• Links to reputable sources, such as the Dietitians of Canada, will help students interpret the need for vitamin or mineral supplements.

Introduction to Carbohydrates and Fiber

• New unit: Module Four begins with carbohydrates and fiber.

• Basic structure of carbohydrates: made of carbon, hydrogen, and oxygen; typically in the ratio of 2:1 for H to O, mirroring the structure of water.

• Two main types of carbohydrates:

  • Simple Carbohydrates: include monosaccharides (single sugar units) like glucose, galactose, and fructose.

    • Monosaccharides: basic building blocks that are absorbable.

  • Complex Carbohydrates: consist of multiple monosaccharides linked together, including oligosaccharides and polysaccharides.

Types of Monosaccharides

• Glucose: primary energy source for cells; found in blood.

• Galactose: component of lactose (milk sugar); a breakdown product of milk.

• Fructose: found in fruits and honey; structurally distinct from glucose and galactose.

Disaccharides and Their Enzymes

• Disaccharides are formed by linking two monosaccharides:

  • Maltose: glucose + glucose; broken down by the enzyme maltase (requires water for hydrolysis).

  • Sucrose: glucose + fructose; broken down by the enzyme sucrase.

  • Lactose: glucose + galactose; broken down by the enzyme lactase.

• Enzymes are located in the small intestine.

Oligosaccharides and Prebiotics

• Oligosaccharides: 3-10 monosaccharides linked together, often referred to as prebiotics, as they serve as food for probiotics (healthy gut bacteria).

• Importance of including foods rich in oligosaccharides in the diet for gut health.

Polysaccharides and Complex Carbohydrates

• Polysaccharides: large molecules made of many monosaccharides; examples include starch and dietary fiber.

  • Starch: digestible form of plant storage carbohydrate.

  • Dietary Fiber: includes cellulose, which humans cannot digest; provides structural support to plants.

Carbohydrates in the Diet

• Recommended intake: 45-65% of daily calories from carbohydrates, focusing on fiber-rich sources.

• Common dietary sources include grains, vegetables, fruits, legumes, and nuts.

• The importance of whole versus refined carbohydrates for optimal health.

Glycogen and Energy Metabolism

• Glycogen: stored form of glucose; found in liver and muscles.

• Liver glycogen serves as a critical reserve of energy for maintaining blood glucose levels between meals.

• Muscle glycogen is utilized locally by the muscle itself during physical activity.

Insulin and Blood Glucose Regulation

• Insulin: hormone produced by the pancreas in response to elevated blood glucose; promotes glucose uptake by cells, glycogen formation, and fat storage.

• Glucagon: hormone that mobilizes glycogen stores to raise blood glucose levels when they drop.

Diabetes Overview

• Type 2 diabetes: characterized by insulin resistance; closely correlated with obesity and sedentarism.

• Trends show that diabetes rates have soared in North America alongside rising obesity rates.

Key Takeaways

• Emphasize the importance of balanced macronutrient intake, focusing on whole foods to meet energy and nutritional needs.

• Be cautious of dietary claims regarding carbohydrates and focus on evidence-based recommendations.