Someone please tell me why we need to drink alkaline water when our stomach has to be acidic to digest food?

Since lemon water is acidic, drinking it makes you feel hungry faster

That is what most people believe. Once digested and metabolized, lemon juice produces alkaline byproducts, which make the urine more alkaline. This is why it is thought of as alkalizing, despite its acidic pH before it is digested.

The Alkaline Diet categorizes foods into one of three groups:
1) Acidifying foods: Meat, poultry, fish, dairy, eggs and alcohol
2) Neutral foods: Natural fats, starches and sugars
3) Alkalizing foods: Fruits, nuts, legumes and vegetables