Whether you’re dieting trying to lose weight or someone like myself who lives with food allergies, it's important to keep a food diary. Some food allergies are more cut-and-dry than others, and for me my dairy allergy falls under the more "cut-and-dry" of the two, but my soy allergy isn't so simple. Even with a diet consisting of mainly unprocessed whole grains, fresh fruit and vegetables, and most of the meals home made as is the case with me, we still depend on some prepackaged products; the oat milk I use, bread (if I'm not up to making it), a few choice canned products, and even supplements.
It never fails that every that every once in a while just when I think I'm in the clear I may experience a reaction (usually the itchy swollen knuckles), and have to figure out what caused it. This is where the food diary comes in handy. If you record the food and the date of when you incorporated this new product into your diet, you can always refer back to that if a reaction occurs; it's also good to record how long the reaction lasted and the severity of the reaction. These entries should include dining out as well as eating at home. If you note what you ate a particular restaurant and you experience a reaction, then you would know not to order that dish again; and the same goes for safe meals. It's always good to know a couple of dishes at a restaurant you like to frequent that you can enjoy.
Lets face it even if you are a very health conscious person like me and enjoy cooking healthy meals, it's always fun to go out with friends or family once in a while and enjoy a meal without that you didn't have to slave over.