One view is for the sake of acid-base balance, and the other view is that a healthy body is weakly alkaline and an unhealthy body is acidic, so we should eat more alkaline food.
If you ask me, it's all nonsense, putting the cart before the horse, just like diabetes. Some people think they eat too much sugar and try their best to control it. In fact, this is caused by endocrine disorders and has little to do with eating sugar. A healthy human body will naturally adjust after eating all kinds of food. Unhealth is caused by other reasons and has little to do with the acidity and alkalinity of food.
I heard this from Japan, but I haven't read the relevant papers in detail, believe it or not.