Dairy, which is almost zero - carb, is substituted with other foods with a higher carb count. (ketodietapp.com)
During school, I would have almonds, peanut butter sandwiches and an array of other foods in my locker so I could eat stuff in between classes. (davedreas.com)
Fortunately, calcium is abundant in other foods as well, especially tofu and green, leafy vegetables. (cathe.com)