Does whey protein contain sugar

It depends. In it's natural state, liquid whey does contain sugar. As for powdered supplements, there are two catagories of whey protein powders.

1) whey concentrate

2) whey isolate

Whey concentrate contains lactose which is milk sugar. People who have trouble digesting this type of sugar are described as "lactose intolerant".

Whey isolate is much purer and contains very little lactose. Therefore, most people who are lactose intolerant can use a whey isolate product and not have any problems.

Beware - there are a lot of companies that blend a little whey isolate into their whey concentrate and then try to deceive you into thinking that it's 100% isolate. They use tricky Wording on the label. Read the label very carefully. Is it really pure isolate or do the just use a little bit of 100% isolate? You should not see the Word "concentrate" anywhere on the list of ingredients.