If you follow an acid alkaline diet, you choose your foods based on the acid-forming or alkaline-forming nature with a ratio of usually 20% acidic foods and 80% alkaline foods. Acidic foods include meat, bread, dairy products, coffee and alcohol. Alkaline foods include most vegetables and many fruits. Citrus fruits which would appear to be acidic are actually alkaline-forming when they enter the body. Proponents say the diet eases conditions caused by high acid intake such as sinus problems, anxiety, depression, fatigue and even cancer.

Physicians who criticize this diet believe that the body constantly works to create the acid alkaline balance no matter what you eat. Increasing or decreasing respiration is one way the body balances itself. Another method is by eliminating excess (either acid or alkaline) through the kidneys in urine.