Late last year, I was having some gastrointestinal issues, and someone suggested I should go gluten-free, as an experiment. I tried it for a few weeks, and it seemed to help.

So I started speaking to a dietician, and we did a bunch of tests to see what was going on. I kept a food diary. I eliminated a lot of different foods, and reintroduced them one by one. I determined that I have a sensitivity to a class of carbohydrates called FODMAPs.

I had heard of FODMAP sensitivity before my dietician told me about it. In a rare case where blogging has materially benefited me, I had blogged about the very same subject almost a decade ago. I had heard of (then recent) research that many people who believe they have gluten sensitivity are actually sensitive to FODMAPs. FODMAPs and gluten both occur in the same food, and so going gluten-free tends to help even if it wasn’t gluten that was the source of the problem.

FODMAP background

Gluten is a protein that occurs in wheat, and it’s what gives dough its elasticity. There’s a disease called Celiac’s, which causes an allergic reaction to gluten, even in small quantities. Other people appear to have non-Celiac gluten sensitivity (NCGS), which is far less severe. It’s contested how much of NCGS is actually explained by FODMAP sensitivity.

FODMAPs are short-chain carbohydrates that ferment in the colon. There are many types, although the FODMAP diet usually talks about just six: fructans, galactooligosaccharides, fructose, lactose, sorbital, and mannitol. Different people may be sensitive to different types.

Fructans in particular, is the one that occurs in wheat, alongside gluten. However, fructans also appears in other foods, most notably garlic and onion.

“Sensitive” usually means that people have gastrointestinal symptoms, irritable bowel syndrome mostly. I was motivated to try gluten-free because I was having GI symptoms. However, I found from testing that my more severe symptoms were headaches. I’ve had chronic headaches all my life, and it wasn’t really on my radar that it could be caused by diet, but it clearly showed up in my food diary. Headaches are not a typical symptom, but the dietician has a “these things are known to happen” sort of response.

Unwarranted skepticism

If you follow the link to what I wrote about FODMAPs on my blog you’ll see that I was complaining about how skeptics had discussed the FODMAP diet when the research was new. I understand that these discussions occurred more than a decade ago, but please allow me my rant. Now that it’s a subject that is directly relevant to my experience, I know more and have even more to complain about!

Skeptics had a thing about NCGS. They didn’t think it existed. To them, it was a health fad. It was part of an industry of overrated food certifications, alongside the “organic” label. So when research came out arguing that most people claiming NCGS actually have something different (FODMAP sensitivity), skeptics took this as confirmation of their views.

From an epistemological standpoint, the problem with health foods is that somebody is trying to sell you something, whose value is mostly invisible and subjective. Pay more for our inferior snack product, and you’ll have a clearer mind or live longer or something–you know, healthy stuff. If the vague promises are not fulfilled, nobody is held accountable. So it’s fair to be critical of the health food industry.

But this criticism feels very misplaced when talking about gluten-free diets. Irritable bowel syndrome is not some subjective symptom that occurs far off in the undefinable future. It’s pretty immediate and not subtle. For me I was having symptoms within a day at most. There are still epistemological challenges, since the typical diet has so many different things in it that it’s hard to identify exact sources. But if someone experiences fewer symptoms after going gluten-free, there’s a certain amount of direct empirical observation that would be difficult to deny.

Skeptics presumed an adversarial relationship between people claiming NCGS, and FODMAP research. That’s absurd. When I found that a gluten-free diet helped, that did not always and forever commit me to the belief that gluten must be the problem. I am happy that there is research showing that fructans is the more likely culprit, because this new knowledge helps me improve my diet.

Skeptics were basically mocking people who claimed to have NCGS for not having figured out the FODMAP thing on their own. Excuse me, how are they supposed to figure it out? When the researchers figured it out, it took a lot of time, money, and expertise. So how should dieters automatically know about it?

I was involved in skepticism for most of the 2010s, but over time I had become increasingly disillusioned—not necessarily with the core values, but with the resultant community that those values had wrought. This is a common backstory for many FTB readers. Looking at this one issue of FODMAPs, it’s difficult not to be cynical about it. Skeptics got this one wrong. What does that say about their epistemological standards and practices? Nothing good.

What diet is like

What’s it like being on a low FODMAP diet? During testing, it was pretty tough. Without knowing which things I was sensitive to, I needed to cut out all FODMAP sources. I have an app with a database of foods, and it feels like practically everything has FODMAPs. Luckily, it’s dosage dependent. So if I got a little here and there, not an issue. In several cases I was eating something that was a source of FODMAPs, but I didn’t realize it until later, and it wasn’t causing issues, so it’s fine actually.

I tested foods as directed by my dietician. First try a low dose, then the next day a medium dose, then a high dose, where dosage is listed in my app. If it was fine, then I didn’t need to eliminate it anymore. So my diet slowly opened up as I narrowed down what I was sensitive to.

Eventually it seemed pretty clear that only fructans and lactose were the issues for me. So that lets me generalize to a lot of foods that I haven’t directly tested yet.

In home cooking, I’ve been sorry to see onion and garlic go. We practically treated them as staple foods before, putting them in everything. Now I put green onions and ginger in everything. Green onions don’t have much fructans, go figure.

Restaurants are a bigger problem, since, just like we used to do in our own cooking, they put garlic and onions in everything. Now imagine that I’m going on a business trip, having obligatory meals at restaurants that I did not choose. Sometimes none of the options are compliant with the diet.

The dosage dependence makes the diet more forgiving. I’ve found that a bit of garlic powder isn’t necessarily a problem. I haven’t had any issues with chickpeas although they’re supposed to have fructans too. A single slice of bread is fine. But that also makes it all the harder when I have to explain the diet. On one of these business trips I told a restaurant about it, and they treated it like I had a garlic allergy—which was excessive but honestly nice.

Later, my dietician suggested I try a supplement. I am not going to name the supplement, since I would feel like a shill. But it’s basically an enzyme for fructans, in the same way people with lactose intolerance will take lactase pills. The supplement is somewhat less convenient than lactase, since it comes in powder form rather than pills, and it’s expensive. I’m not putting it on everything, but it seems to open up options quite a lot.

I don’t like having to restrict my diet, but overall I’m happy with the outcome. I didn’t imagine when I started that I would more or less cure my chronic headaches. That’s a huge win.