Citric acid is a rare food intolerance suffered through by a minority of people, necessitating its removal from the diet to ensure an absence of digestive difficulty. Removing citric acid from your diet might seem as simple as removing the consumption of all citrus fruits from the menu, but it's not quite that easy. Many foods that you would not expect contain some quantity of citric acid either naturally or as an additive, making wholesale elimination of this substance potentially complicated.
Begin with the obvious and remove all citrus fruits from your diet--limes, oranges, lemons, grapefruits and similar fruits. This will excise a fair portion of your daily citric acid consumption from your diet, but more work must be done to clean up foods that contain trace amounts.
Eliminate consumption of other fruits that contain citric acid from your diet to further remove foods which contain smaller--but still potentially harmful--traces of citric acid. These include all berries except blueberries--you'll need to stop eating strawberries, cranberries, raspberries, blackberries, and the like. Additionally, cherries also contain a tiny amount of citric acid, so it is best to avoid them if you are dedicated to completely removing this substance from your diet. Finally, pineapple is another potential source of citric acid, so avoid it where possible.
Eliminate foods which are produced through fermentation, as the process of fermentation can cause citric acid to develop in a handful of food types, including wines and sourdough bread. Avoid these foods to dodge an unexpected but present dose of citric acid.
Watch out for other foods which may have citric acid added as an ingredient. While this is by no means an exhaustive list, some of these foods include jellies and jams, colas and other soft drinks, ice cream, canned fruit, and mayonnaise (as it is often made by using lemon juice). Additionally, you will want to remove all cheeses from your diet as well, as they are often made with added citric acid, which forces milk to clot faster than it otherwise would. In general, you will have to remain vigilant, checking the ingredients of the foods that you consume to ensure that some amount of citric acid does not fly by under your radar.