Calculating carb content of recipes

You can work out the carbohydrate content of meals and recipes by using the steps we’ve covered in the last few topics.

For working out the carbohydrate content in a recipe, follow the steps below:

• Identify each item from the ingredients list that contains carbohydrate

• Work out how much carbohydrate is in the portion of each ingredient that is to be counted

• Add together the carbohydrate value for each ingredient

• Divide the total carbohydrate by the number of each serving

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Worked example for calculating carbohydrate in recipes

Using the steps above, let’s calculate the carbohydrate content for the following recipe:

Step 1: Identifying foods containing carbohydrate

In this meal, the items that we need to find out the carbohydrate content for are:

• Black beans (drained weight)
• White rice (cooked)
• Taco shells

Step 2: Work out carbohydrate content of each item

Black beans – Net weight = 400g, Drained weight = 235g

Typical values	Per 100g	1/2 of a can (117g)
Energy	462kj / 110kcal	541kj / 128kcal
Fat	0.6g	0.7g
Saturates	0.1g	0.2g
Carbohydrate	15.1g	17.7g
of which sugars	0.5g	0.5g
Fibre	7.1g	8.3g
Protein	7.5g	8.7g
Salt	<0.01g	<0.01g
As sold, drained

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The total carbohydrate content for ½ a can is 17.7g. As we are using a full can, we need to double this figure, which equals 35.4g. We’ll round this down to 35g.

Taco shells

Typical values	Per 100g	Each taco shell (13g) as sold
Energy	2126kj / 509kcal	276kj / 66kcal
Fat	27g	3.5g
Saturates	2.3g	0.3g
Carbohydrate	59.2g	7.7g
of which sugars	1.0g	0.1g
Fibre	3.6g	0.5g
Protein	5.4g	0.7g
Salt	0.05g	0.01g
Contains 12 portions

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Each taco shell contains 7.7g of carbohydrate. As we need 8 in the recipe, we will multiply this by 8, which equals 61.6g. We’ll round this up to 62g.

White rice

Food item	Portion	Weight (g)	Average g carb per portion
Rice (cooked)	1 heaped tablespoon	40g	13g
	small serve	100g	32g
	medium serve	180g	57g
	large serve	290g	91g
Rice (raw)		100g	78g

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From the Diabetes UK reference guide, we can get the values for cooked rice. 100g of cooked rice is 32g of carbohydrate.

For the recipe, we need to work out the value for 150 grams of cooked rice. We have the value of 100 grams and can then work out the value for 50 grams. We then need to add these values together to get that value of 150grams:

The value for 50g is 32 divided by 2 which equals 16. We then add 32 and 16 together to get the carbohydrate content for 150g of cooked rice = 48g.

So the carbohydrate content for all 3 items are:

The total carbohydrate content for the meal is 145g.

As the recipe serves 4 people, (and assuming that you are creating 4 equal sized portions), we would divide the total carbohydrate content by 4 which equals 36.25g. We’ll round this down to 36 grams per serving.

Now we know how to work out the carbohydrate content of foods and recipes, we’ll explain how you match this with your bolus insulin in the next few topics.