In my personal opinion, one to two cups of skimmed milk, or curd is fine on a daily basis. but we also live in times where cases of lactose intolerance are on a high.
Avoid these-
people with several lactose intolerance must check the nutritional label for the following:
1. whey
2. Lactose
3. curds
4. Milk byproducts
5. dry milk solid
6. Non-fat dry milk powder

A must have in Indian household and an eternal favorite.