@ickihun , the added sugar thing can be a bit confusing, especially when comparing full fat, semi-skimmed and skimmed milk labels.
Unless we're talking about milk products, like milk shake, or flavoured milks, no sugar is added, but the semi and skimmed variants appear to have more sugar, per 100ml due to the processing they have been through.
If you start with 100ml full milk, then take some, or all of the fat out of it, then you are left with fat in one vessel and reduced fat milk in another. Naturally, having taken the fat off, there will be less than 100ml left. So, to make 100ml semi or skimmed milk, it takes more than 100ml full fat product and because all the natural sugars are left behind in the processing, the semi and skimmed variants will have more in, per 100ml.
Does that make sense?