Article: Glycemic Index (GI)

Glycemic Index GIThe New Zealand ministry of health recommends that the average New Zealander eats 6 servings of carbohydrates per day however, not all carbohydrates are created equal…

What is the Glycemic Index

The glycemic index ranks carbohydrate foods according to how quickly they release their sugars into our blood stream. High GI foods are ranked as 70 or above on the Glycemic index, where as medium GI food are ranked 56-69 and Low GI 55 and under. Most food labelling will not give a GI rating so I have included a general list for you to follow. Generally speaking refined carbohydrates such as waffles will have a high GI rating and wholemeal products will have a low GI rating. We can also use the GI index to rank fruit and vegetables.

Why is knowing the GI ranking of food important

A high GI food will release its energy quickly (think chocolate fix). If that energy is not used (through exercise) it will become stored in your body. The easiest was for your body to store energy is in the form of fat. Because high GI foods release their energy quickly you will feel hungry not long after eating. Low GI food release their energy slowly which give you a longer time period to ‘use’ the energy and will therefore keep you feeling fuller for longer.

The benefits of a low GI diet

  • Low GI diets help people to lose and control their weight
  • Low GI foods reduce the risk of heart disease
  • Low GI foods reduce blood cholesterol levels
  • Low GI foods reduce hunger and keep you feeling fuller for longer
  • Low GI foods prolong physical endurance
  • High GI foods help re-fuel carbohydrate stores after exercise
Food GI Serving Size
Peanuts 14 4 oz (113g)
Bean sprouts 25 1 cup (104g)
Grapefruit 25 1/2 large (166g)
Pizza 30 2 slices (260g)
Lowfat yogurt 33 1 cup (245g)
Apples 38 1 medium (138g)
Spaghetti 42 1 cup (140g)
Carrots 47 1 large (72g)
Oranges 48 1 medium (131g)
Bananas 52 1 large (136g)
Potato chips 54 4 oz (114g)
Snickers Bar 55 1 bar (113g)
Brown rice 55 1 cup (195g)
Honey 55 1 tbsp (21g)
Oatmeal 58 1 cup (234g)
Ice cream 61 1 cup (72g)
Macaroni and cheese 64 1 serving (166g)
Raisins 64 1 small box (43g)
White rice 64 1 cup (186g)
Sugar (sucrose) 68 1 tbsp (12g)
White bread 70 1 slice (30g)
Watermelon 72 1 cup (154g)
Popcorn 72 2 cups (16g)
Baked potato 85 1 medium (173g)
Glucose 100 (50g)

Learning More: Additional information and values for Glycemic Index and Glycemic Load can be found at

Article by Rebecca Logan – NZIS Christchurch Tutor

New Zealand Institute of Sport