Factors governing the effect of carbs in our bodies

Of course, not all carbohydrates are created equally.

The speed at which carbohydrates go from being food to increasing our blood sugar levels varies depending on a number of factors. Such as:

physical state of the carbohydrate
In simple terms, liquids get digested far more rapidly than solids. So the carbohydrates in beer or fruit juice enter our blood stream much more quickly than if we ate the same as a piece of bread or fruit.

A good reason to avoid ‘drinking your calories’.

the type of carbohydrate
There are two types of carbohydrate. Simple sugars such as glucose, sucrose (table sugar), fructose and lactose. And so called ‘complex carbohydrates’ which are the starches found in bread and pasta.

For carbs to enter out blood stream to be used for fuel (or stored as fat) they must be converted to the simple sugar ‘glucose’.

You’d think that the complex carbohydrates, which are large molecules, would take longer to be converted to glucose and be absorbed into our blood streams. But they are actually just made up of lots of little ‘glucoses’ so it actually happens quite quickly.

Table sugar, on the other hand is made up of one glucose + a fructose. So when we digest it, half goes into the blood stream quickly but the other half, the fructose gets processed by our livers.

For example, if we compare regular corn flakes breakfast cereal (made up of corn = complex carbohydrate) to frosted flakes (the same corn coated with as much sugar as possible). The regular flakes actually increase our blood sugar more quickly than the frosted flakes.

This is because the sugar contains half fructose, which is digested differently to the glucose in the corn.

the presence of fructose
The problem with fructose or ‘fruit sugar’ is that our bodies can only process it in our liver.

So while fructose doesn’t cause an increase in blood sugar and the release of insulin, it actually gets stored directly as fat. When we eats lots of fructose our liver converts it to fat and either stores it as fat in our liver or sends it off to be stored in our fat tissue.

This is why it’s important to avoid processed foods and drinks containing ‘hi fructose corn syrup’.

It’s also why if your healthy eating goals include weight loss you should limit your intake of fruit and focus on getting all your vitamins, minerals and antioxidants through vegetables.

Of course, if weight maintenance is your goal, fruit can not only be a great source of fibre and important nutrients. It’s also fun.

presence of fibre
Fibre is the stuff in food we can’t digest so when it is present in food, it tends to slow down the time it takes for the things we can digest to be processed.

This means a more gradual increase in blood sugar levels, decreasing the chance of insulin spikes. Definitely a good thing.

presence of protein & fat
Both of these macronutrients slow down the rate at which we digest carbs. A good thing from a slow and steady approach.

the speed we eat
Quickly wolfing food down, will increase blood sugar levels more quickly than a more leisurely approach to eating. It also makes it more difficult to stop eating when we are full.

our personal insulin sensitivity
Everyone is different in how sensitive their bodies are to insulin.

People who are very sensitive tend to be thinner because when they do eat lots of carbs and their blood sugar increases, insulin gets released, their bodies are sensitive to the insulin and quickly brings their blood sugar back to normal. So insulin goes away quickly and they start burning fat for fuel. Happy days.

Other people aren’t so lucky. The less sensitive to insulin we are, the more insulin needs to be released to do the same job. This means insulin is in our blood streams for longer periods so we spend more time storing fat and less time burning fat. You can guess the effect of that on our waistlines.

The other thing to note is as we age, we become less sensitive to insulin. It’s a cruel world 😉

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