Monosaccharides – The simplest form of carbohydrates, consisting of single sugar molecules (e.g., glucose, fructose, galactose).
Disaccharides – Carbohydrates composed of two monosaccharides bonded together (e.g., sucrose, lactose, maltose).
Polysaccharides – Complex carbohydrates made of long chains of monosaccharides (e.g., starch, glycogen, fiber).
Sucrose – A disaccharide made of glucose and fructose; commonly known as table sugar.
Lactose – A disaccharide made of glucose and galactose; the primary sugar in milk.
Fibers – Indigestible carbohydrates found in plant-based foods that aid digestion and provide health benefits.
Gluconeogenesis – The process of producing glucose from non-carbohydrate sources, such as proteins.
Insulin – A hormone produced by the pancreas that helps lower blood sugar levels by facilitating glucose uptake into cells.
Glucagon – A hormone that raises blood sugar levels by promoting glycogen breakdown in the liver.
Glycogen – A polysaccharide that serves as stored glucose in the liver and muscles.
Soluble fiber – A type of fiber that dissolves in water and helps lower cholesterol and regulate blood sugar (e.g., oats, beans).
Insoluble fiber – A type of fiber that does not dissolve in water and promotes digestive regularity (e.g., whole grains, vegetables).
Nutritive sweeteners – Sweeteners that provide calories, such as sugar and high-fructose corn syrup.
Nonnutritive sweeteners – Artificial or natural sweeteners that provide little or no calories, such as aspartame and stevia.
Glycemic index (GI) – A measure of how quickly a carbohydrate-containing food raises blood glucose levels.
Glycemic load (GL) – A measure that accounts for both the glycemic index and the carbohydrate content of a food serving.
Main function of carbohydrates – Provide energy for the body, particularly for the brain and muscles.
Basic unit of all carbohydrates – Monosaccharides.
Differences between carbohydrate types:
Monosaccharides: Single sugar units (glucose, fructose, galactose).
Disaccharides: Two sugar units (sucrose, lactose, maltose).
Polysaccharides: Long chains of sugar units (starch, glycogen, fiber).
Purpose of insulin – To regulate blood glucose by promoting glucose uptake in cells.
Low carbohydrate intake consequences – Can lead to gluconeogenesis and ketosis.
Blood glucose regulation – Managed by insulin (lowers blood sugar) and glucagon (raises blood sugar).
White sugar – Sucrose.
Principal carbohydrate in milk – Lactose.
Fiber digestion – Beneficial gut bacteria help ferment and break down fiber.
Glycogen storage – Stored in the liver and muscles as an energy reserve.
Soluble vs. Insoluble fiber:
Soluble fiber examples – Oats, beans, apples, carrots.
Insoluble fiber examples – Whole wheat, brown rice, leafy greens.
WHO recommendation for added sugars – Less than 10% of total daily energy intake.
Carbohydrate digestion enzymes:
Amylase – Breaks down starch into maltose.
Maltase – Breaks maltose into glucose.
Lactase – Breaks lactose into glucose and galactose.
Sucrase – Breaks sucrose into glucose and fructose.
Fiber and cholesterol:
High-fiber diet – Can lower cholesterol by binding bile acids.
Low-fiber diet – May lead to higher cholesterol and heart disease risk.
Adequate fiber intake:
Women: ~25g/day
Men: ~38g/day
Fiber-rich foods – Whole grains, fruits, vegetables, legumes.
AMDR for carbohydrates – 45-65% of total daily calories.
Example calculation: If consuming 2000 kcal/day, carbs should be 900–1300 kcal (225–325g of carbs).
Who should monitor glycemic index? – People with diabetes or those managing blood sugar levels.