Will we increase in weight if we eat ice creams. or the fat will increase by eating icecream ?

A bit of both: Ice cream tastes so good because it has plenty of sugar, creamy milkfat, great flavors, and even eggs in it. It does cause weight gain if one eats too much of it. A small amount of ice cream in an otherwise normal, healthy diet is usually no problem. When a person gains weight, the weight is "fat" weight, unless he is working out and building more "muscle" weight.