Data and Methods

When I first started my low FODMAP journey, I had a very difficult time finding data on the FODMAP content of foods. Many websites promised to tell me which foods are high and low FODMAP. But all they did was tell me what a popular app says. That wasn’t what I wanted.

What I wanted was data on the FODMAP content of common foods. I wanted to know which FODMAPs are in which foods and in what proportions. I wanted data that could help me make my own decisions about foods to try and foods to eliminate. But no one would tell me that. They just told me to buy the app. So I started doing my own research.

You can read the about page to learn more about me and why I don’t use FODMAP apps.

I found out that there’s actually a lot of data out there on FODMAPs. But much of it is hidden away in specialized databases or academic journals. Some of the best data isn’t really available to the people it could help most.

I decided to use my research training to summarize that data and make it available to people like me. People who want to educate themselves and make informed decisions about their digestive health, without blindly following an app.

Below I describe some of the data sources I use most often in my research for FODMAP Essentials, so you can better understand where this information comes from.

Data Sources

My research for this website relies on two types of sources: nutritional composition databases and academic journals.

Many governments maintain nutritional composition databases. These databases report data from government-sponsored studies. In the United States, this research is conducted mostly by the US Department of Agriculture (USDA). Since I live in the US and write from a US perspective, I rely heavily on the USDA’s nutritional composition database, FoodData Central.

FoodData Central is a great resource, but it doesn’t always have the data I need. Fortunately, many other governments have similar databases. I often draw from these, too. The French government’s database, Ciqual, is especially helpful.

If you don’t live in the US and are wondering if your country has a comprehensive nutritional database, you can check out this list of national nutritional databases maintained by Langual.

Another database I often consult is that at This organization supports people born with congenital sucrase-isomaltase deficiency, which renders them unable to digest certain sugars. The CSID database is a great resource for finding the breakdown of sugar content in food.

The non-database source I use most is academic journal articles. Research on FODMAP content in foods is done by all sorts of scientists, not just dietitians. As such, I consult a pretty wide variety of academic sources. I try to link to journal articles that are publicly available on Google Scholar. But even if an article can only be found in an academic database, I always include a full citation.


Since I’m not working in a research lab, I don’t have methods in the traditional sense. What I do is summarize data from different sources to help readers better understand the FODMAP content of foods.

Sometimes data sources agree; most of the time they don’t. When that happens, I often use the data to provide high and low FODMAP estimates for foods. You can see here I did that when estimating the sorbitol content of peaches.

Sometimes I come across data that doesn’t make sense. I point that out, too, as I did here when I found a really low estimate for the mannitol content in button mushrooms.

So, I assess the quality of my data sources and strive to only provide high-quality information. And I always link to the original source, so you can check it out for yourself, if you want.

Update Procecedures

New food composition studies are published nearly every single day. Despite what some other websites may lead you to believe, no one app or set of researchers is the absolute authority on the topic of FODMAPs. That said, it’s impossible to keep up with all the new research. Here is how I try to stay on top of things for FODMAP Essentials.

As mentioned, my primary source for nutritional composition data is the USDA’s FoodData Central. FoodData Central gets two major updates each year, in April and October. I keep track of these updates and, if they relate to any data on this site, I update that blog post with the new information.

I also regularly review new academic research. I do this with alerts from GoogleScholar and also from large academic databases like Springer and Ebscohost. If there’s research I feel sheds new light on a topic covered on this website, then I update the blog post to incorporate it.

Whenever a post receives a major update, I add a note to the beginning of the post. This note includes the day of the update and what new information was added. So, readers can always see when the most recent update to any post has occurred.