The natural sugar that is in milk is lactose and that is not really a problem (as long as you are not lactose intolerant of course).

The problematic sugar is refined fructose. That is the stuff cannot be properly processed by the body and causes all kinds of chaos for your metabolism.

Even naturally occurring fructose, such as in fruit, is ok. But once you concentrate it into crystallized sugar or HFCS, it becomes a slow acting poison.

In the US, plain yogurt would show any added sugar in the ingredients list (it would not reflect the amount).

But it starts from milk, so there is lots of sugar it in.

There has been new legislation passed that starting..next year?..labels will have to show total sugar and added sugar, so you can realistically get a sense of how much is original vs. additive.

Yeah I get that, it's just that you can already tell if something like plain yogurt has added sugar or not. In my experience, most brands list milk and the bacteria cultures.

I guess varying the preparation of the yogurt can still result in a wide range of sugar content.

That's a great point. I just checked and it doesn't list it. I don't know why I never thought of that.