Glycemic Index

Moderate GI

56-69

High GI

70 or more

Low GL

<80

High GL

>100

Glycemic Index

A scale that ranks carbohydrates by how much they raise blood glucose levels compared to a reference food

Amylose

Absorbs less water Molecules form tight clumps Slower rate of digestion (lower GI: Kidney beans, Uncle Ben's converted LG rice)

Amylopectin

Absorbs more water Molecules are more open Faster rate of digestion (higher GI: russet potato, glutinous rice)

Acid Content

Acid slows down gastric emptying, and thus, slows down the digestion of starch.

Physical Entrapment

Bran acts as a physical barrier that slows down enzymatic activity on the internal starch layer. (lower GI: pumpernickel bread, all bran higher GI: bagel, corn flakes)

What should I eat?

Consume 2 cups fruit, 2½ cups vegetables per day. (2,000 calories intake) Choose whole grains for at least half of daily grain consumption Consume 3 cups FF/LF milk or equivalent

Cooking

Cooking swells starch molecules and softens foods, which speeds up the rate of digestion.

Fat and protein content

Fat and protein slow down gastric emptying, and thus, slows down digestion of starch.

Glycemic Load calculation

GL = GI/100 x CHO (grams) per serving

Glycemic load

Glycemic load measures the degree of glycemic response and insulin demand produced by a specific amount of a specific food. Glycemic load reflects both the quality and the quantity of dietary carbohydrates

Food Processing

Highly processed foods require less digestive processing.

Factors influencing GI ranking

Starch, Physical Entrapment, Viscosity of Fiber, Sugar Content, Fat and protein content, Acid Content, Food Processing, Cooking

Viscosity of Fiber

Viscous, soluble fibers transform intestinal contents into gel-like matter that slows down enzymatic activity on starch. (lower GI: apple, rolled oats, higher GI: whole wheat bread, cheerios)

Sugar Content

sugar -> sucrose glucose + fructose (GI 60) (GI 100) (GI 19) starch -> maltose glucose + glucose (GI 105) (GI 100) (GI 100)

Benefits of low GI diet

lowers blood glucose levels, cholesterol levels, weight, heart disease risk, type 2 diabetes risk, improves lipid levels

Moderate GL

100

Low GI

0-55