Low FODMAPS Diet for IBS

What's a FODMAP? It's an acronym that stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. FODMAPS include fructans, galactans, polyols, fructose, and lactose.

In plain English? A FODMAP is just a type of short chain carbohydrate that - for some people - is poorly digested. FODMAPS are naturally found in certain fruits, vegetables, milk and wheat.

In addition, some common manufacturing by-products are pure FODMAPS. Inulin, FOS, GOS, MOS, XOS, oligosaccharides, artichoke extract, and chicory extract are examples of FODMAPS that are commonly added to foods, drinks, and supplements.

Note that gluten is not a FODMAP.

Gluten is a protein. FODMAPS are carbohydrates. Fats, proteins, and carbohydrates are separate macronutrients.

A gluten free diet is required for celiac disease, but not for IBS. IBS does not carry gluten intolerance and gluten free foods are not automatically safe for IBS.

A low FODMAPS diet is NOT a blanket exclusion diet.

You are not supposed to remove all high FODMAP foods from your diet forever. That is going to lead to malnutrition.

You are only supposed to do the low FODMAP diet working with a registered dietitian who knows both IBS and FODMAPS specifically.

It takes about 12 weeks of exclusions/reintroductions to run down your personal FODMAP intolerances - if any - and to find your specific degree of tolerance levels.

About 30% of people with IBS have NO FODMAP intolerances at all, so it’s a useless diet for them.

I think of FODMAPS as the cherry on the IBS diet sundae. You need to get your foundation built first. Establish your baselines with the universal IBS trigger foods (GI stimulants, irritants), soluble fiber safe foods, and insoluble fiber caution foods. These will physically affect your IBS gut in very predictable ways. Making these foundational diet changes may be all you need.

If you do get your foundation established, and still have trouble, especially bloating and gas, then try adding in FODMAPs exclusions with a registered dietitian.

The low FODMAP diet, and IBS dietary advice in general, can also seem overwhelming and contradictory. Hang in there, there are a lot of clear, easy steps to take that should get you feeling better quickly.

First of all, before you can even accept a diagnosis of IBS, let alone start a low FODMAP diet, you need to be tested for gluten intolerance (celiac), fructose intolerance, and lactose intolerance. All of these can mimic IBS but they are different problems, and require different dietary strategies.

If you have these food intolerances ruled out and you do have IBS, then the FODMAP approach isn't always the easiest, fastest, or best way to start. Again, about one third of people with IBS don't have any FODMAP intolerances.

The low FODMAP diet can also mistakenly lump together gluten, fructose, and lactose intolerances with IBS, and they are not remotely the same thing.

Remember, gluten isn't even a FODMAP - it's a protein. FODMAPS are carbohydrates. Fats, carbohydrates, and proteins are all discrete and unrelated elements.

The original author of the low FODMAP diet, Dr. Sue Shepherd at Monash University in Australia, touched on these crucial issues in her actual scientific research papers. Somehow those details are often dropped as her research is disseminated down the line to America, from medical papers to more patient-oriented publications. If you follow a low FODMAP diet, make sure you are accounting for this oversight so you can get the best results possible.

First things first, make sure that you've had the tests for those food intolerances so you know what you're truly dealing with. Then, focus on your soluble fiber safe foods, eliminate the universal IBS trigger foods, and be cautious with insoluble fiber foods.

There is an IBS diet cheat sheet for quick and easy reference and a fridge post.

Remember that with IBS, it is also a matter of HOW you eat, not just WHAT you eat.

Get your foundation diet of eating for IBS established and see how you do with that. You might not need to take things any further.

If you do, it's crucial that the low FODMAPS diet is trialed only under the direct supervision of a registered dietitian. This is because it is NOT a blanket exclusion diet.

The FODMAP dietitian should help you figure out which specific - if any - FODMAPS groups bother you. And then they need to find the highest amount you can tolerate. This is to make the FODMAP diet as unrestrictive as possible, and this can only be done on an individual basis.

What you don't want is to eliminate, forever, all high FODMAPS foods across the board.

You may well have a problem with none of them, or just some of them, and to varying degrees. It is a very individualized diet.

It can also be complicated, which is why it's supposed to be done with a registered dietitian. It is a serious problem to just eliminate all high FODMAPS foods, probably unnecessarily, as you'll end up with a very nutrient-poor diet as a result.

In addition, there is worrisome research showing that a low FODMAP diet negatively impacts the gut biome, and the healthy bacteria of the gut. As a result, the low FODMAP diet is not suggested on a permanent basis, and research into the consequences of a low FODMAP diet is continuing.

Interestingly, a 2018 study found that prebiotic supplementation could replace the low FODMAPs diet as a treatment for IBS. The study compared the results of a prebiotic soluble fiber supplement plus a Mediterranean-type diet, versus a placebo supplement plus the low FODMAP diet.

Fecal microbiota composition, intestinal gas production, and digestive sensations were all measured outcomes. While both groups showed improved GI symptoms, only the prebiotic group showed significant improvements in microbial composition. Alarmingly, the low FODMAP group actually showed an increase in pathogenic-associated bacteria. In addition, following the dietary intervention, improvements persisted only in the prebiotic group - not the FODMAP group. If you want to learn more about prebiotics for IBS see here.

If you do work with a registered dietitian on the low FODMAPS diet, make sure they also address the standard high fat trigger foods and GI irritants, and the importance of soluble fiber safe foods. Excluding high FODMAPS foods without adjusting your diet for the other IBS concerns is much less likely to give good overall results.


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