The Carb Challenge

Apples aren't always apples

Guess the Carbs in each Apple:

Take a look at both apples and guess how many
units of Humalog (lyspro) would you take for each. Answers below…

Carbohydrate in the food we eat has the greatest impact on our blood sugars. Diets high in complex carbs (like vegetables, root crops, whole grains, and fruit) provide healthy nutrition for a long healthy life without heart disease and cancer. This health benefit contrasts with high-fat foods that are associated with obesity, heart disease, insulin resistance and higher blood sugars in the long run.

But with diabetes, carbs must be balanced with insulin (either injected or internally produced) or exercise to keep blood sugars normal (another important part of long, healthy life). Balancing carbs with insulin lets you keep your blood sugars controlled, and carb counting is an important tool for doing this.

So, How Many Carbs In The Apples?

On a gram scale, the Rome apple on the left weighs 238 grams, while the Gala on the right weighs 139 grams. Since apples are 13% carbohydrate by weight, the carbohydrate content of each apple is:

Rome:    238   X   0.13   =   30.9 grams of carb
Gala:      139   X   0.13   =   18.1 grams of carb

How Much Insulin For Each Apple?

The table below gives estimates, based on your total daily insulin dose (TDD = all long-acting and short-acting, or all basals and boluses typically used per day), estimates how much Humalog insulin will likely be needed to cover each apple. Add up your typical TDD, then look in column one for your TDD and across to see your estimated coverage for each apple. (These numbers are given as estimates only! They should never be used to cover an apple or other food without a full discussion with your physician!)

Estimated Insulin Need Based on the 500 Rule
If your Total Daily
Insulin Dose is:
It is likely 1 unit of
Humalog will cover:
So the Rome apple
will need:
But the Gala
will only need:
20 units 25 grams 1.2 u 0.7 u
25 units 20 grams 1.5 u 0.9 u
30 units 17 grams 1.8 u 1.1 u
35 units 14 grams 2.2 u 1.3 u
40 units 13 grams 2.4 u 1.4 u
50 units 10 grams 3.1 u 1.8 u
60 units 8 grams 3.9 u 2.3 u
75 units 7 grams 4.4 u 2.6 u
100 units 5 grams 6.2 u 3.6 u

See also Carb Counting, the Glycemic Index and the Satiety Index