Not All Carbs are Equal: Understanding the Glycemic Index Anna Chetrick, MS, RD, CDE

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1 Not All Carbs are Equal: Understanding the Glycemic Index Anna Chetrick, MS, RD, CDE March 10, 2018

2 Let s start with the basics 62 grams carb Carb ratio = 8 Insulin dose = ~8 units BG should be under 180 two hours after dosing/eating. Right? 2

3 Are all carbs really equal? VS GI=36 GI=74 3

4 What is the Glycemic Index? The Glycemic Index (GI) is a relative ranking of carbohydrate in foods according to how they affect blood glucose levels within the first 2 hours after ingestion. Scale from 0 to 100 Carbohydrates with a low GI value (55 or less) are more slowly digested, absorbed and metabolized and cause a lower and slower rise in blood glucose and, therefore insulin levels. It s a measurement of speed. 4

5 Are all carbs really equal? VS GI=36 GI=74 Only 36% of pizza s carbs turn into blood glucose within the first 2 hours 5

6 Should I dose my insulin differently based on GI? MDI Splitting the carb dose Start with 50% at the beginning of the meal and 50% minutes later Always give the full dose needed for correction at the beginning of the meal Pump Dual Wave or Extended Bolus Start with 50% at the beginning of the meal and 50% over the next 2 hours Use CGM graphs to help guide timing of doses Give injection or bolus minutes before eating high GI foods 6

8 How is the GI different from complex carbs or simple carbs? Media-based Terms such as complex carbohydrates and simple sugars are now recognized as having little nutritional or physiological significance. The WHO/FAO recommend that these terms be removed and replaced with the total carbohydrate content of the food and its GI value. Evidence-based! GI value of a food is determined by feeding 10 or more healthy people a portion of the food containing 50 grams of digestible (available) carbohydrate and then measuring the effect on their blood glucose levels over the next two hours. 8

Foods that carry the symbol are guaranteed to have been

9 GI Symbol Program The GI Symbol Program was launched in Australia in 2002 to help consumers identify the GI of foods. Foods that carry the symbol are guaranteed to have been properly tested by an accredited laboratory using the international standard. 9

10 How should I use the Glycemic Index? Low GI Medium GI High GI Instead of This Try This! White Potato (82) Sweet Potato (44) White Rice (72) Brown Rice (50) Cornflakes (81) All Bran (38) Instant Oatmeal (83) Old Fashioned Oats (42) Regular Pasta (58) Whole Wheat Pasta (32) Bagel (72) Whole Wheat English Muffin (45) Corn, boiled (60) Broccoli (0) or Carrots, cooked (39) Baked Beans (53) Black Beans (20) Instant Mashed Potatoes (87) Green Beans (0) Powerbar (83) Almonds (0) Fiber Plus Bar (78) Apple (38) Clif Bar (101) Banana (52) Raisins (64) Grapes (46) Cheese Pizza (60) Thin Crust Cheese Pizza with Veggies(30) Potato Chips (57) Dried Apple Chips (29) Macaroni and Cheese (64) Whole Wheat Cheese Tortellini (50) White bread (80) 100% Whole Grain Bread (51) Shortbread cookies (64) Nutella (25) on Whole Grain Bread (51) Cranberry Juice Cocktail (68) Water (0) 10

11 High, low, or medium GI? GI = 45 11

12 High, low, or medium GI? GI = 83 12

13 High, low, or medium GI? GI = 62 13

14 What about treating hypo? High GI foods can help offset hypoglycemia Glucose tablets = 102 Skittles = 70 Coca Cola = 63 Orange juice = Rule Take 15 grams of carbs Re-check your blood sugar in 15 minutes Do not use chocolate, high fat foods, whole foods, or low GI foods 14

15 What is the difference between glycemic index (GI) and glycemic load (GL)? How high BG rises and how long it remains high after eating depends on the quality of the carbohydrates (the GI) and the quantity (the serving size). Glycemic load or GL combines both the quality and quantity of carbohydrate in one 'number'. GL = (GI x the amount of carbohydrate) divided by

Calculating Glycemic Load Let's take a single apple as an

Its GI is 80 and it contains 15 g of carbohydrate.

16 Calculating Glycemic Load Let's take a single apple as an example. It has a GI of 40 and it contains 15 grams of carbohydrate. GL = 40 x 15/100 = 6 g What about a small baked potato? Its GI is 80 and it contains 15 g of carbohydrate. GL = 80 x 15/100 = 12 g We can predict from this that our potato will have twice the metabolic effect of an apple. 16

17 What about fiber? Soluble fiber Thick and jelly-like (viscous) in solution (water) Foods with more soluble fiber have low GI values Fruits, vegetables, legumes (beans, peas and lentils) and some cereal grains (oats and barley). Insoluble fiber Often described as roughage Doesn t slow digestion of a food Wholegrain cereals and products that retain the outer layer bran of the grain (corn, oats, quinoa, rice, spelt, wheat), and in vegetables, nuts and seeds. 17

18 Why not just adopt a low carbohydrate diet to keep my blood glucose levels and weight down? Low carb diets are unnecessarily restrictive (bread, potato, rice, grains and most fruits are restricted) and may spell trouble in the long term if saturated fat takes the place of carbohydrate. Low GI diets strike a happy medium between low fat and low carb diets - you can have your carbs, but must choose them carefully. 18

19 Why bother with all this? After meal BG spikes can cause: Tiredness Difficulty concentrating Impaired athletic performance Increased hunger Increased urination Thirst, dry mouth Blurry vision Mood shifts Food works much faster than even the fastest acting insulin! Making food work slower = lower post meal spike Reducing your exposure to high BG will reduce A1c and therefore prevent long-term complications due to hyperglycemia 19

20 Putting it all together Glycemic Index has been proven most helpful to people with diabetes Foods with a lower GL tend to have a lower GI anyway Foods higher in fiber tend to be lower in GI anyway When given the option, choose the lower GI food Experiment with bolusing earlier, minutes before high GI foods Use high GI foods to treat hypo Choosing high fiber, less processed, whole foods will always be the most beneficial 20

21 Questions??? 21

Glycemic Load & Glycemic Index

Glycemic Load & Glycemic Index Load & Index When food is consumed it is converted to fuel for our bodies. One type of fuel is glucose and different foods impact blood glucose levels differently. A driver of this is the amount and type