Eat fewer oxalate-rich foods.

Eat fewer oxalate-rich foods. If you tend to form calcium oxalate stones, your doctor may recommend restricting foods rich in oxalates. These include rhubarb, beets, okra, spinach, Swiss chard, sweet potatoes, nuts, tea, chocolate and soy products.
Foods High in Oxalate
Drinks: Beer, chocolate milk, soy drinks, tangerine juice, juice of almost all berries and fruit cocktail, and hot cocoa.
Fruits: Rhubarb, currants, lemon, marmalade, purple grapes, tangerine and berries.
Vegetables: Cucumber, kale, green peppers, celery, eggplant, escarole, beets, chives, okra, parsley, spinach.
Grains: Whole wheat bread, popcorn, wheat bran, oatmeal, white corn and soybean crackers.
Legumes, Nuts and Seeds: Beans, baked beans, peanut butter, sesame seeds, sunflower seeds, peanuts, almonds, pecans, cashew and walnuts.
Condiments: Black pepper, cinnamon and ginger.
Starches: Fruit cake, sweet potatoes and grits.