Presentation on theme: "Carbohydrate Digestion Good Carbs, Bad Carbs, Insulin and You!"— Presentation transcript:
Carbohydrate Digestion Good Carbs, Bad Carbs, Insulin and You!
What Happens When You Eat? Carbohydrates are broken down to glucose, raising blood glucose levels Brain stimulates pancreas to release insulin, to transport glucose from blood through cell membrane
Car Analogy… 1. Gas (fuel) must get to the engine in order to burn and be converted to energy. 2. Many gas tanks have “keys” to open the gas tank. The key is needed to get fuel into the car. 3. Gas goes to the engine, where it is “burned” releasing stored energy to move the car. Fuel E
Comparing Your Body to Car Analogy Food & O 2 Digestive System Respiratory System E C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + E Cellular Respiration occurs in the mitochondria (engine) Key Cell (car)
What is Insulin? A hormone (chemical messenger) made and secreted by the pancreas. 3 Functions of Insulin: 1. transports glucose from bloodstream, across cell membrane (the key) 2. removes excess glucose from blood and stores as “body fat” (key also opens car’s trunk for storage) 3. “locks up” glucose in body fat storage, making it hard to use.
Good Carbs vs Bad Carbs Some diets refer to Carbs as “good” or “bad” Its not that Carbs are “good or bad”, it is how you blood sugar and insulin respond. Good carbs describe foods higher in fiber and complex carbohydrate Bad carbs describe “refined” foods by removing nutrients, fiber, and adding sugar.
Good Carbs They provide more nutrients, and digest slower. Results in a slower rise in blood glucose. Less likely to be rapidly converted and stored as “Body Fat”.
Bad Carbs Since Bran (seed cover) has been removed, they digest rapidly. Results in a rapid rise in blood glucose Body senses high levels, rapidly removes glucose from blood and rushes it into “storage” as body fat.
Blood Glucose and Insulin Response to Types of Carbohydrate
Glycemic Index (GI) Measure of the quality of carbohydrate in a food Measured by how rapidly the body breaks down the carb and converts it into glucose. Measured on scale of 1-100. (Glucose is 100) Foods with Low GI breakdown slower, resulting in a slower rise in blood glucose. Foods with High GI breakdown faster, resulting in a rapid rise in blood glucose
Glycemic Index Scale Pure Glucose measures 100. High >=70 Medium 55-69 Low <55
Blood Glucose Response to Good Carbs and Bad Carbs Good Carbs (low GI) digest slower Results in slower rise in blood glucose Results in slower, and less insulin released Avoids the “bonk”, rapid drop in blood sugar, leaving a person lethargic feeling Bad Carbs (high GI) digest rapidly Results in fast rise in blood sugar Results in faster and more insulin released. Causing glucose to rapidly drop, bottoming out. Creates “craving” for for more Carbs
Effects of Too Many High GI Foods Over Time Constantly elevated insulin levels lose their effectiveness to remove glucose from blood (insulin resistance) Since insulin levels stay high and can’t move glucose into cells, they store excess blood glucose as body fat. Insulin “locks up” excess glucose in fat cells, making it difficult to be used. Obese people fat cells block the receptor sites for entry into muscle. RESULT: TYPE II DIABETES