There are many different definitions and approaches of an elimination diet, but I'm going to share mine as an online gut health coach that uses the tool as one approach to help individuals manage their gut health.
And I'll be staying to the point...
An elimination diet involves removing a selection of foods, usually common allergens and sensitivities or foods that you suspect you cannot tolerate, before gradually reintroducing some of these foods to get back to a regular eating schedule.
I find them useful for two reasons:
1. During the re-introduction process you can pinpoint how you react to given foods when they are introduced - meaning you can identify how your body reacts and tolerates these foods.
2. During the period whilst these foods are removed, you limit the food sources that the bad bacteria in your gut feed on - and in turn limit symptoms like bloating - whilst you get to the root cause of any digestive issues you may have (like an imbalance of bacteria or leaky gut). As you re-introduce foods, with the correct overall approach and proper supplementation, your body is able to tolerate foods that it couldn't prior because you've now addressed the issue.
This is a key element of the 3-phase nutrition plan on my coaching plan The Gut Reset, which eliminates and moderates common allergens, food sensitivities, refined foods, sugars, FODMAPs, and more - before re-introducing them in a specific order (alongside the other elements of the plan) to get you back to a place of normal eating.