Whenever I give a talk and make the statement that a normal blood sugar represents less than one teaspoon of sugar dissolved in the blood, I’m often met with scepticism. It really is true, however.
Let’s go through the calculations so we can see exactly how this plays out.
First, we need some basic measures.
one liter (l)= 10 deciliters (dl)
one gram (gm) = 1000 milligrams (mg)
one teaspoon = 5 grams
According to the American Diabetes Association the line between a healthy fasting blood sugar and a pre-diabetic fasting blood sugar is set at 100 mg/dl (pronounced 100 milligrams per deci-liter). A fasting blood sugar of between 100 mg/dl and 125 mg/dl earns a diagnosis of pre-diabetes, and a fasting blood sugar of over 125 mg/dl is diabetic.
So how much sugar is 99 mg/dl, the highest fasting blood sugar you can have and not be diagnosed as pre-diabetic? Let’s figure it out.
We know that a typical human has about 5 liters of blood, so we need to figure out how much sugar dissolved into this 5 liters of blood will give us a reading of 99 mg/dl.
Since one liter contains 10 deciliters we multiply 99 mg/dl by 10, which gives us 990 mg, the amount of sugar in one liter. Multiply the 990 mg in one liter times 5, the number of liters of blood in the human body, and we have 4950 mg of sugar. If we divide the 4950 by 1000, the number of mg in a gram, we get 4.95 grams of sugar.
Since one teaspoon contains 5 grams, the 4.95 grams of sugar in the blood of a person just short of being pre-diabetic equals a little less than one teaspoon.
If you run all these calculations for a blood sugar of 80 mg/dl, which is a much healthier blood sugar than the 99 mg/dl one that is knocking on the door of pre-diabetes, it turns out to be about 4/5 of a teaspoon.
If you run the calculations for 126 mg/dl, the amount of sugar in the blood of someone just over the line into the diagnosis of diabetes, you find out that it is 6.25 grams, or 1 1/4 teaspoon. So, the difference between having a normal blood sugar and a diabetic blood sugar is about a quarter of a teaspoon of sugar.
What really gets kind of scary is when you look at the amount of carbohydrate in, say, a medium order of McDonald’s fries compared to the sugar in your blood. Remember, it is the job of your digestive tract to breakdown the starch and other complex carbohydrates, which are nothing more than chains of sugar molecules, into their component sugars so that they can be absorbed into the blood. An order of medium fries at McDonald’s contains 47 grams of carbohydrate. 47 grams of carbohydrate converts to about 47 grams of sugar, which is almost 10 teaspoons. So, when you eat these fries you put 10 times more sugar into your blood than that required to maintain a normal blood sugar level. If you figure, as we did above, that one quarter of a teaspoon is all the difference between a normal blood sugar and a diabetic blood sugar, the 10 full teaspoons would be 40 times that amount.
Since your metabolic system has to work very hard indeed to deal with the sugar load from an order of fries, imagine what it has to do when you add a large soft drink, a hamburger bun, and maybe an apple turnover for dessert.
When you see the long lines of cars in the at the drive-through window and the long lines of customers at the counter inside, you can see why the incidence of type II diabetes is skyrocketing?