Nutrition - Lecture 2

What are carbohydrates primarily composed of?

Carbon, hydrogen, and oxygen.

How are carbohydrates classified from a nutritional perspective?

Based on the number of sugar units.

What are simple carbohydrates?

Carbohydrates with fewer than 3 sugar molecules.

What is a monosaccharide?

A carbohydrate that consists of one sugar molecule.

Name the three types of monosaccharides.

Glucose, galactose, and fructose.

What is glucose known as in the body?

Blood sugar; it circulates providing fuel to cells.

What is lactose?

A disaccharide composed of glucose and galactose; known as milk sugar.

What is the primary function of carbohydrates?

To provide energy to the body (4 kcals/g of carbohydrates).

What happens to excess glucose in the body?

It is stored as glycogen in the liver and muscles or converted to fat (lipogenesis).

What is gluconeogenesis?

The metabolic process that generates glucose from non-carbohydrate precursors.

What is the glycemic index (GI)?

A scale that ranks carbohydrate-containing foods by how fast they raise blood sugar levels.

What are complex carbohydrates?

Polysaccharides that include starch, glycogen, and fiber.

What is the recommended daily allowance (RDA) for carbohydrates?

A daily minimum of 130 grams to prevent ketosis.

What are whole grains?

Grains that are not overly processed and retain all three parts: bran, germ, and endosperm.

What is the difference between whole grain and whole wheat?

Whole grain retains all parts of the grain, while whole wheat is processed and loses most of the germ and bran.

What are sugar alcohols?

Lower-calorie sweeteners like sorbitol and xylitol, commonly used in chewing gum.

What is the daily intake recommendation for simple sugars?

Less than or equal to 25% of total daily calories.

What is the role of insulin in glucose regulation?

Insulin moves glucose into cells when blood glucose levels rise.

What is lipolysis?

The breakdown and oxidation of fat stores for energy when glucose is insufficient.

What are the two categories of dietary fiber?

Soluble and insoluble fiber.

What is the function of soluble fiber?

It slows digestion and binds fatty acids and cholesterol.

What is the function of insoluble fiber?

It adds bulk to stool and helps with regularity.

What is the significance of dietary guidelines from Health Canada regarding added sugars?

To promote dental health and avoid excessive calorie intake.

What are non-nutritive sweeteners?

Sugar substitutes that contain few or no calories.

What is aspartame?

A non-nutritive sweetener made from aspartic acid and phenylalanine, 150 times sweeter than sucrose.

What is the recommended intake level for aspartame in Canada?

40 mg/kg body weight per day.

What is stevia?

A plant-derived non-calorie sweetener that is not considered a food additive.

What is the primary source of carbohydrates in our diet?

Plant-based foods, dairy products, and processed foods with added sugars.