What is the logic in Carbohydrates section ?

Marus

Hi,
I am very confused about what is shown in the Carbohydrates section. If I sum up the amount in grams of Fiber, Net Carbs, Starch, Sugars, I don't get the number from Carbs. After a while I thought that the logic is this: Starch + Sugars = Net Carbs, and Net Carbs + Fiber = Carbs. That seems quite close to the results I get, but not always. For example, I tried with 100 g of "walnuts". Starch is 0.1g / Sugars is 2.6g. Summed together they are 2.7g, but Net Carbs shows 6.8g ! Again, 6.8g Net Carbs + 6.7 Fiber does not give 13.7g like Carbs shows. So, what is the logic ?
Thanks !

Susan_RD_101

Hi @Marus

Net carbs = total carbs minus fibre. The rationale for this calculation is that fibre doesn't have much of an impact on blood glucose levels since it's not as absorbable in the human digestive tract.

Total carbs includes: starch + sugar + fibre. I personally wouldn't worry about adding these numbers up each day, trying to get them to equal total carbs, since a lot of rounding is used when determining the nutrition facts.

Hope this helps!

Marus

Indeed, from 13.5g to 13.7g it can be a rounding error.
But the difference is significant when I sum up the Net Carbs (Starch + Sugars). 2.7g is very far from 6.8g. I think maybe those walnuts have another kind of carbohidrate that is not listed in Cronometer (which is not so important).

Karen_Cronometer

Hi @Marus ,

You are right, there are likely other carbohydrates in the walnuts that are not measured directly. USDA and NCC analyzes many carbohydrates - but this does not capture every carbohydrate component out there. Instead of adding up the carbohydrate components listed to get the total carbohydrate value, USDA calculates this value by subtracting the values for water, ash, alcohol, protein and fat. The idea is that once you remove all of these components the rest must come from carbohydrates.

Best,

Marus

I am glad to hear that. I was afraid that it was an error in the database.
Thank you for clarifying !