what I learned from FODMAP elimination and reintroduction

As I mentioned recently, I’ve had IBS (Irritable Bowel Syndrome) for three years now and have struggled to get the symptoms under control. My number one issue is bloating, and although it doesn’t interfere with my life the way, say, unpredictable diarrhea would, it’s still a significant annoyance. (Diarrhea and constipation are very common IBS symptoms but not ones that trouble me.) My belly puffs up easily so my clothes need to have a bit of stretch or they don’t fit. It’s a bit of a blow to body image and it makes me not want to take photos. I’m sure part of that is vanity and subscribing to society’s notion of what is or isn’t attractive, but I also I don’t feel like I look like myself.

I did some research online and found a book that looked promising (Patsy Catsos, IBS — Free at Last!, 2nd ed. (Portland, ME: Pond Cove Press, 2012). It looks at the role that FODMAPs (fermentable oligo-, di- and monosaccharides, and polyols) may play in IBS symptoms. FODMAPs are basically fermentable simple carbs. (FYI Monash University in Melbourne is the leader in FODMAP research, so their resources are the most reliable. The Catsos book is based exclusively on Monash research but it’s getting a little out of date now.)

There are five categories of FODMAP carbs:

  • lactose, found in milk and some milk/dairy products (a simple carb [disaccharide/two sugar molecules, in this case galactose + glucose])
  • fructose, found mostly in fruit (a simple sugar [monosaccharide/one molecule])
  • fructans, wheat and onions are top sources (a simple carb [oligosaccharide/three or more fructose molecules, up to a maximum of 10)
  • galactans, legumes/pulses are a top source (a simple carb [aka galacto-oligosaccharide/three or more galactose molecules, up to a maximum of 10)
  • polyols, none of which I’d heard of other than sorbitol, but they’re naturally occurring in some fruits and vegetables like prunes, mushrooms, dates and avocados (aka “sugar alcohols” though they’re neither a sugar nor an alcohol)

In the first phase, you eliminate (the majority of) FODMAPs for two weeks with the goal of getting things settled down. It only took about a week before the bloating pretty much stopped, hooray! I don’t ordinarily weigh myself often but I’ve now gotten into a routine of weighing daily, which revealed I’d also been retaining water. I had almost resigned myself to having to buy new clothes to fit my different circumference, but it looks like that won’t be necessary now.

I’ve now done all five challenges. I found it difficult to get enough food containing the target carb in one day to give a good test and so I may retest a couple categories. That said, I observed that lactose and polyols didn’t cause a reaction, fructose and galactose caused a mild to medium reaction, and fructans caused a strong reaction. For me the usual reactions are bloating and gas, but it’s possible that the problem FODMAPs also affect my energy and mood.

(To be clear, none of these carbs are inherently “bad”. What the FODMAP testing shows is that each person’s metabolism is unique, and what results in optimum function for one person may be much less than optimum for someone else.)

My big takeaway so far is that I need to tread very cautiously with fructans. The North American diet gets about 70% of its fructans from wheat and about 25% from onions. My strategy is to start with cutting out wheat; onions will get scrapped only if necessary. And since my issue with wheat is not a gluten allergy (celiac disease), it’s not going to do me any harm if I get trace amounts of wheat in my diet from prepared foods. All the IBS does is cause inconvenience, and it’s up to me which inconvenience (bloating versus the hassle of avoiding certain common foods) I avoid and which I accept.

I’m getting a checkup next week and when I speak to the doctor I’ll ask him what testing, if any, is available here for these different categories of carbs. I’ve certainly learned something from trial and error, but I’d like more rigorous testing so I get clearer results.

This isn’t the only issue I have with carbs. I’ve also had difficulties with hypoglycemia over the years.

Food Matters