carbs and duration

This varies per person.
But you get an idea by looking at the glycaemic index.

In people who produce enough of their own insulin, the insulin begins to be produced as soon as any food hits the tongue, sometimes even before that if they are drooling over gorgeous cooking smells. This is any food. The problem with T2 people is the insulin doesn't work properly due to insulin resistance in the cells, which is why it takes longer for them to return to normal levels after eating. After eating certain foods the glucose released from the carbs can be instant - such as with sugary sweets like jelly babies, or even bananas, whilst other carbs take a bit longer to convert to glucose, and some foods take a lot longer..

winglets said:

[QUOTE="After eating certain foods the glucose released from the carbs can be instant - such as with sugary sweets like jelly babies, or even bananas, whilst other carbs take a bit longer to convert to glucose, and some foods take a lot longer..

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And generally what kind of foods would those be? Foods that have a high carb content but less sugar e.g oats, cereal?[/QUOTE]

I suggest, as @helensaramay suggested, that you search and look up the glycaemic index.

It also makes a bit difference on what else is eaten with the carbs. Plenty of fat and protein for example. Pizza is well known to be a very late peaking food.

You must also remember that though sugar is not a nutrient (it is a refined chemical roughly consisting of half fructose and half glucose) but must be counted as a carbohydrate because of the way that the human body metabolises it. So, if you look on the nutrient table on the back of a pack of food you will see the amount of carbs and below that you may see the phrase 'of which sugars' because sugar and carbs are basically metabolised in the same way along the same pathway. We normally ignore the 'of which sugars' as the number is added already to the carb value.

In my experience sugary foods spike me faster than other carbs, but the result is largely the same re: the actual numbers.

My understanding is that for a normal person, their first-stage insulin response (i.e. the insulin that the pancreas has in the tank already) will take care of all the carbs in the blood - but for most T2Ds our first-stage response is compromised, so it takes longer for the body to clear the sugar as it produces the insulin required.