Imagine you are a car and your blood stream is your petrol tank. Blood sugar is your fuel.
Forget foods from animal origin like meat, chicken, egg, cheese and fish, they don’t affect your fuel system – think of them as air for the tyres. Neither does fat – its oil for your engine.
That leaves the plant foods. Forget about most vegetables and fruits as we tend not to over eat them, especially with a sleeve or band. Just don’t eat a kilo of grapes at once, spread it over the day, avoid juice and limit dried fruit to a couple of tablespoons
That leaves grains – bread, rice, pasta, crispbreads, breakfast cereal and a few starchy vegetables. These foods raise your BGL because they contain carbs.
Carbohydrate is just glucose bound together, so when you digest it, it breaks down to sugar and enters your blood stream to become ‘blood sugar’.
One slice of bread will contribute around 3 tsp sugar to your tank and that’s a good thing, because we all need petrol.
The point of the Gi is that some carbohydrate foods are digested quickly and dump a heap of petrol in your tank all at once. This leads to a spike in BGL levels that tapers off slowly over the day. The car runs better on drip feeding – slowly digested carbs that enter the blood stream over time.
The difference between a high and low Gi slice of bread is not the amount of blood sugar it delivers as they both deliver the same, rather at what pace they deliver it.
A high Gi white slice of bread with a Gi of 80 could dump 3 tsp sugar in 20 minutes compared to a slice of Burgen Soy Linseed bread at Gi 45, that could release it over the next hour or so. Look for foods with a Gi of 60 and under. You need to average 45. Occasional high Gi meals do not matter.
See the SydneyUniversitywebsite www.glycemicindex.com for a searchable data base of foods and more information. Consider signing up for their newsletter as it is very good.
Purchase the Low Gi Diet Shoppers Guide as it is essential for following a low Gi diet, it is under $20.
Once you master the Gi, read about the Gl (glycemic load) which gives a high Gi food a second chance.
By the way sweet potato is white not orange, the orange sweet potato is kumera and is a common misunderstanding in Diabetes.