Basically, the alkaline diet is opposite the high protein, high fat, low carb diets that are currently in vogue. Most people have never heard of alkaline-acid balance, but many holistic doctors and nutritionists consider a properly balanced diet to be important to optimal health and preventing diseases such as cancer. The theory behind an alkaline diet is that because our body’s pH level is slightly alkaline, with a normal range of 7.36 to 7.44, our diet should reflect this and also be slightly alkaline.