What is the G.I. ?

The G.I. stands for glycaemic index, which is the number given to a carbohydrate food as a ranking of how quickly that food raises blood glucose (sugar) levels. Low G.I. foods raise blood glucose levels slowly and gradually whereas high G.I. foods raise blood glucose levels quickly.
Low G.I. <=55 Medium G.I. = 56-69 High G.I => 70

Why is a low G.I. diet so beneficial ?

Low G.I. diets result in a slower release of insulin from the pancreas (the hormone that helps glucose get into our cells for energy). This is beneficial because high amounts of insulin (stimulated by high G.I. foods), prevent our fat stores from being used for energy, and promote the storage of fat in our bodies. Ongoing stimulation of insulin release by high G.I. foods can 'exhaust' the pancreas and may lead to the development of type 2 diabetes. Also, with the rapid rise and fall of blood glucose levels after eating high G.I foods, you may crave carbohydrates or sugary foods and feel hungry sooner. Low G.I. foods keep you full for longer and stimulate less insulin, allowing your body to burn more fat.
Low G.I. eating is beneficial for everyone and can help with: prevention & management of type 2 diabetes, reducing risk of heart disease, lowering blood fats, weight loss, reducing sugar cravings, reducing insulin resistance, managing polycystic ovary syndrome, and increasing physical endurance.

Is it the same as eating 'complex carbohydrates' instead of 'simple carbohydrates' ?

No. These terms relate to the structure of carbohydrates. Some 'simple' carbohydrates (which are assumed to raise blood glucose quickly), such as fructose (fruit sugar), actually have a low G.I. and therefore raise blood glucose slowly. Likewise, some 'complex' carbohydrates like potatoes have a high G.I. Forget about the terms 'simple' and 'complex' and remember the terms 'low GI' and 'high GI'.

What about low carbohydrate diets ?

These diets are not the same as low G.I. diets. They reduce the total amount of carbohydrates eaten, forcing the body to make glucose out of protein and use fat for energy. Low carb diets should only be used for a short period of time and must be done under the guidance of a health professional. They are not a long term solution to weight loss, and because the body needs carbohydrates, a low G.I diet is a healthier way to promote long term weight loss.

Does this mean I can't eat high G.I. foods again ?

No. Use the 80 / 20 rule; Your health will benefit if the majority of your diet focuses on foods with a low to medium G.I. If you are going to eat a high G.I food, eat it at the same time as a low G.I. food, this will lower the overall G.I of the meal (making it a medium G.I.). High G.I. foods can also be beneficial after strenuous exercise to replenish energy stores more quickly, but be sure to follow it with a low G.I. snack.

What are some examples of low G.I. foods ?

• Multi-grain bread
• Vita-wheat crispbreads
• All-bran cereal, Special K, porridge, Crunchola cereal
• basmati rice (low to medium GI)
• nuts
• milk, soy milk, yoghurt
• apples, oranges, strawberries
• lentils
• baked beans
• pasta
• sweet potato
• yellow box honey
• carrots, green peas, corn cob.
• sushi

Also; milk chocolate, corn chips (doritos), & pizza are low G.I. but high in fat and should be eaten in moderation.

References and Recommended reading :

• 'The new glucose revolution' series of books (especially 'Shopper's guide to GI values', and 'The glucose revolution'') by Prof Jennie Brand-Miller, Kaye Foster-Powell, & others. Other books in the series include; 'losing weight', 'people with diabetes', 'healthy kids', 'top 100'.
• Visit the GI website



Blue Mountains Wellness Centre

Acknowledgements:
This article also published online at www.intrahealthclinic.com
Images courtesy of Barron, Karin mtb, Fotomele under creative commons licence