[4] Alternative medicine practitioners who have promoted the alkaline diet have advocated its use in the treatment of various medical conditions, including cancer.

According to the Academy of Nutrition and Dietetics, portions of his diet such as the emphasis on eating green leafy vegetables and exercise would likely be healthy.

"[7] It has also been proposed that acid causes rheumatoid arthritis and osteoarthritis, and that an alkaline diet can be used to treat these conditions.

These advocates propose that diets high in acid-producing elements will generally lead the body to become acidic and thereby foster disease.

[2][12] While a selectively alkaline diet may change the pH level in the urine, it has not been shown to elicit a sustained change in blood pH levels, nor to provide the clinical benefits claimed by its proponents, because it is "virtually impossible" to create a less acidic environment in the body.

[13] This proposed mechanism, in which the diet can significantly change the acidity of the blood, goes against "everything we know about the chemistry of the human body" and has been called a "myth" in a statement by the American Institute for Cancer Research.

[10][needs update] While it has been proposed that this diet can help increase energy, lose weight, and treat cancer and heart disease, there is no evidence to support any of these claims.

Spurred by these observations, subsequent investigations focused on the chemical properties and acidity of constituents of the remains of foods combusted in a bomb calorimeter, described as ash.

Other investigations showed specific foods, such as cranberries, prunes and plums had unusual effects on urine pH.

[14] Historically, the medical application of alkaline diets largely focused on preventing recurrence of kidney stones as well as the prevention of recurrent urinary tract infections, by relying on the recognized ability of such diets to affect urinary pH.

[15] While there have been recent improvements in recognizing different variables that can affect acid excretion in the urine, the level of detail needed to predict the urinary pH based on diet is still daunting.