What is a low-purine diet? A low-purine diet is a meal plan based on foods that are low in purine content. Purine is a substance that is found in foods and is produced naturally by the body. Purines are broken down by the body and changed to uric acid. The kidneys normally filter the uric acid, and it leaves the body through the urine. However, people with gout sometimes have a buildup of uric acid in the blood.