Analyzing Your Food Diary To Find Trigger Foods

In my previous post I described how to keep a food diary that would provide a good foundation for doing an analysis to find trigger foods. I suggest taking a look before trying to apply the sort of analysis that I describe below.

So what's the simplest method for analyzing a food diary? The first thing that comes to mind is to just look at the times where your symptoms are bad, and look to see what foods you ate prior to that. At first glance this approach seems reasonable, but consider what happens with foods that you tend to eat more often than others. Let's say that someone's favorite snack is chocolate, and they have some almost every day. Well, odds are that if you look at every time their symptoms flare up and check what they ate prior to these flare-ups, you'll find chocolate pretty often. Does that make it a trigger food? It's possible, but this analysis isn't providing good evidence of that. What's needed is some way of dealing with the fact that different foods/ingredients vary greatly in how often they're eaten.

How do you deal with this variability in how often things are eaten? Well, rather than starting by looking at symptom flare-ups, you could start by looking at the foods. Take each food that was eaten, find every time it shows up in the diary, and look at whether it was following by a flare-up. A simple way to rate each food would be to take the percentage of the time it's followed by a flare-up. You could then rank the foods by their percentages, and the top foods would be your possible trigger foods.

This method of analysis forms the basis for how TriggerFood works, with some extras added in like taking symptom ratings into account and looking at entire food categories like dairy foods or fried foods.