One of the most frustrating things about counting carbs is finding foods which the listed carb content doesn't match the effect on my blood sugar. For instance I find that with Nairns Gluten Free Oatcakes I have to totally disregard what the listed carb amount is and through trial and error have worked out the correct amount for me.
On the packaging it states:
Carbs Per 100g = 53.3g
Carbs Per Oatcake = 4.8g
The oatcakes come packaged in three pouches of six - so using the amount per oatcake then one pouch would contain 28.8g. However I have found that by using this amount I will always end up going low - and the actual amount which works for me is 12g per pouch. That is a huge difference. Its not down to the slow release of the carbs in the oatcakes as I don't get a rebound high a few hours later when I use 12g.
It would seem that it is either a) a problem with my absorption of this particular food or b) incorrect labelling.
I also have problems with soups and usually have to adjust the carb count downwards - is this due to the bio-availability of carbs from certain vegetables or perhaps again it is just my absorption? I don't have problems with foods like potatoes, pasta, rice, fruit etc so my ratio's definitely are not the issue.
I find this sort of thing very annoying as it adds an extra layer of complexity to an already tedious task. Does anyone else have any particular problems with certain foods?