I have a question. When you are reading food labels and it says sugar under the carbohydrates, do you subtract that from the actual carbohydrates like fiber or not?

No, sugar is the big kahuna of carbs!

Sugar is actually the worst carb. So, never ever ever subtract anything but fiber and SA's (if they don't stall you) from total carb count.

how do I know if they re sugar alcohols or not

Usually the package will state "Sugar Alcohols" and the amount of them on the Nutrition Information thingy. If it doesn't, check the labels for things like mannitol, sorbitol, xylitol, lactitol, isomalt, maltitol and hydrogenated starch hydrolysates (HSH). Sugar alcohols are not commonly used in home food preparation, but are found in many processed foods. Food products labeled “sugar-free,” including hard candies, Low carb cookies, chewing gums, soft drinks, Low or no carb chocolates, and throat lozenges often consist of sugar alcohols. They are frequently used in toothpaste and mouthwash too. These are okay, but in some people they cause stalls in weight loss, and in alot of folks, too much of them can cause rather unpleasant side-effects, such as cramps, gas, bloating, and diarrhea. It did in me, and while those lovely nearly no carb chocolates were quite yummy, In my opinion, the pain they caused me just was not worth it!

Hope this helps!!