This was a originally written as a guest post for Paleo Britain (you can find the post here). However, as it is such an important topic for me, and for this blog (as essentially FODMAPs is a big part of the reason I started this blog), I thought I’d pop it up here too.
Writing a post about FODMAPs has been at the front of my mind for a while now. In my opinion, it’s a large and important topic, so when Paleo Britain approached me about writing a post, I knew FODMAPs would be a great topic to dive into!
History of the Low-FODMAP diet
While the low-FODMAP diet has gained quite a lot of traction in Australia and New Zealand over the last five years or so, it’s been slow to take off in other parts of the world. As a result, many people haven’t heard of it yet.
For some of you, the name Peter Gibson might ring a bell. He is the man who originally put non-celiac gluten sensitivity (NCGS) on the map. After releasing his studies on NCGS, he began questioning whether gluten was actually the cause of gastrointestinal distress or whether there was something else at play. Using a group of participants who didn’t have celiac disease, but were convinced they had gluten sensitivity, he ran a number of studies where participants were put on one of three diets: gluten-free, low-gluten, and high-gluten. Participants were unaware of which diet they were consuming.
Gibson separated out all potentially problematic food groups such as lactose, specific preservatives, and FODMAPs. His aim was to discover if one of these groups was responsible for intestinal symptoms instead of just gluten. The study revealed that FODMAP, not gluten (although gluten containing grains are included in FODMAP groups), was the cause of symptoms often attributed to gluten sensitivity. While Gibson has only recently come out with his findings, FODMAP has been around since 1999 when Sue Shepherd first developed the diet.
Testing for sugar malabsorption
At the end of 2009, my gastroenterologist sent me to do a bunch of breath tests so they could test for sugar malabsorption. While FODMAPs may trigger symptoms of IBS and other digestive issues, there are specific breath tests you can do that will determine your individual sensitivity to certain sugars — in particular: fructose, lactose and sorbitol.
The breath tests were long and drawn out. They involved adopting a very plain diet for two weeks and going in every day to drink a clear liquid of the sugar they were testing (only one sugar at a time) to monitor my reactions to it. They work on the basis that the bacteria in the large intestine produces hydrogen and methane gas by fermenting carbohydrates. Most of the gas produced is transferred across the lining of the large intestine and into the bloodstream, which is then carried into the lungs where it can be measured through breath. It takes a while, but the results are quite worth it. My tests came back highlighting fructose and lactose intolerance.
It was from that point I loosely adopted the low-FODMAP diet. I started with the elimination process; eliminating all the FODMAP groups and then slowly bringing one back at a time.
So what are FODMAPs?
Essentially they’re a group of naturally occurring sugars that are not absorbed into the small intestine. Instead, they continue travelling down to the large intestine where (normal and healthy) bacteria is present. The bacteria sees the unabsorbed sugar as a food source and when they eat the FODMAPs, they ferment them, producing and releasing hydrogen, carbon dioxide and methane gases that can lead to excessive flatulence, gassiness, bloating, abdominal distension, and pain. All that awful embarrassing stuff, basically! FODMAPs can also change the way your bowels work very quickly, so if your susceptible to changes in your bowel it’s quite likely you could experience constipation, diarrhoea, or a combination of both if you react to FODMAPs.
FODMAPs stands for:
The science is quite complicated for most regular folk, so I’ll try and explain it in a way I wish I’d have been told at the start. (I’m sorry, it still involves a lot of necessary science speak!)
Fermentable is what we have just talked about – poorly absorbed sugars being fermented by bacteria in the large intestine. How quickly the molecules are fermented depends on the chain length – oligosaccharides and simple sugars are fermented very quickly when you compare them to fibre, which contains much longer chain molecules (polysaccharides).
Oligosaccharides are individual sugars that have joined together to make a chain. The two main FODMAP oligosaccharides are fructans (fructose sugars that join together to make a chain with glucose at the end), and galacto-oligosaccharides (also known as GOS) made up of galactose sugars joined together with fructose and glucose at the end. Some fructans you will probably recognise are onions, nectarines, garlic, wheat, rye, barley, chickpeas andcashews to name a few. And GOS? You’ll find GOS in beans (eg. kidney, baked, black, cannellini, pinto, lima, butter, soy, fava) as well as lentils and chickpeas.
Disaccharides means two individual sugars that have joined together to make a double sugar. Only one disaccharide can act as a FODMAP in food and that is lactose. Lactose is made up of an individual glucose sugar joined to an individual galactose sugar. I’m sure many of you know about lactose – it occurs naturally in animal milks including milk from cows, sheep and goats. When lactose reaches the small intestine it is broken down into its component sugars by the enzyme lactase. Those of you with lactose intolerance may have taken lactase pills at one time or another – they’re not bad huh? Those pills are basically this enzyme which goes in there to help break down the lactose so it’s digestible.
Monosaccharides are individual sugars. The most important, problematic monosaccharaide that can act as a FODMAP is fructose which is also called ‘fruit sugar’. If you’re on the low-FODMAP diet you will probably find that you don’t need to avoid all fructose, it’s just those foods that contain more fructose than glucose (excess fructose foods) that need to be avoided. If a food has more glucose than fructose, or if fructose and glucose levels are even, then it is suitable on the low-FODMAP diet – however, only one piece of fruit should be consumed at a time. This area can get a bit confusing, so I’ll give you an example. Honey is a fructose heavy food. It has 40 grams of fructose per 100 grams, while it only has 30 grams of glucose per 100 grams. This means it is not suitable on the low-FODMAP diet. Kiwi fruit has 4 grams of both fructose and glucose per 100 grams, meaning it is suitable to include in a low-FODMAP diet. Other unsuitable foods under fructose are apples, boysenberries, cherries, pears, asparagus, sugar snap peas, agave nectar, high-fructose corn syrup(obviously!) and fruit juice concentrate.
Polyols are often commonly referred to as sugar alcohols such as sorbitol, mannitol, maltitol, xylitol. The two polyols most commonly found in foods are sorbitol and mannitol. Polyols are found in some fruits and vegetables and are often used by food manufacturers as binding agents and artificial sweeteners (think sugar-free gum, mints and candy). High-polyol foods include apples, apricots, blackberries, peaches, nectarines, cauliflower, snow peas, plums, nectarines, prunes, watermelon and mushrooms.
Phew, so that’s the big heavy science stuff out of the way. I promise, the more you read it the more you’ll become familiar with the different strands of FODMAPs. It’s also important to emphasise that you don’t have to avoid all FODMAP foods. You can of course, if you choose to, but it’s not necessary. It’s taken me five years to fully realise that in order for the good of my health and my digestive system I have to adopt a full low-FODMAP diet. But for many years I just chose strands of the diet which seemed to work for me.
The process starts with an elimination diet which you follow for eight weeks. This means you avoid ALL FODMAPS for this time. If you find your symptoms have improved after this time, you can gradually reintroduce one FODMAP group at a time to see how you tolerate it. You may want to experiment with the different foods in each food group as you may not tolerate a food item in one FODMAP group, but you may be fine with low levels of another. See what works for you.
When I was reintroducing FODMAPS I started with fructans. I knew I was sensitive to fructans due to my issues with wheat, rye and barley. I started with apples, both cooked and raw, with disastrous results. I was so sick I didn’t try and reintroduce any other fructans for another week. Through my elimination and reintroduction I discovered apples, wheat and onions are complete no-go territories for me. Nectarines, however, I can have occasionally, and garlic I can tolerate in small doses. It’s the same in the fructose category – apples, pears, asparagus, watermelon, mango and cherries are all bad news for me but I can happily eat a good amount of bananas, pineapples, kiwi fruit, and oranges with no problem. It’s about finding what works for you and what doesn’t. That’s how I’ve operated over the past five years at least. Now I’m just eliminating all high-FODMAP foods to try and keep my gut smiling (to the extent that a gut can happily smile).
Are you vegetarian or vegan?
Don’t worry, you can all eat very well on a low-FODMAP diet, but it does require planning. Many plant-based proteins that vegetarians and vegans base their diet around contain FODMAPs (e.g.: whole wheat, barley, legumes, some nuts, and soy) therefore you may be at risk of not meeting your daily protein needs if you don’t tolerate these foods. You should be able to get most of your protein by consuming suitable nuts, seeds, tofu and tempeh (or other suitable soy products), cereal products based on high-protein, low-FODMAP grains and protein-enriched milk alternatives. If you don’t need to be gluten free (although I personally recommend everyone should live gluten free as I really don’t think gluten is good for anyone) then you can incorporate seitan into your diet as it’s made entirely of protein and has none of the problematic FODMAP carbohydrates.
A self-tailored diet
Remember, the low-FODMAP diet is highly individual. The whole point of FODMAPs is not to restrict your diet to be plain, boring and repetitive (except at the very start). The goal is to allow you to eat a balanced, healthy and interesting diet without having to deal with digestive distress! I should also point out, this diet is primarily used for those with gastrointestinal problems. It’s not necessarily recommended for those who are perfectly healthy and I’d check with your doctor or a nutritionist who is aware of the FODMAPs diet if you’re unsure it’s right for you.
I did ditch the low-FODMAP diet for a while when I went 100% paleo. Paleo, at its essence, didn’t work for me because many high-FODMAP foods are encouraged in paleo recipes. After getting incredibly sick, watching my leaky gut come back to a severe extent, and being miserable for a number of months, I backed off the paleo (and my overconsumption of nut based products that went hand in hand with my paleo diet) and reintroduced an entirely low-FODMAP diet. It’s taking some time, but I’m slowly getting back to good health, and I’m still loosely following the paleo diet. I still avoid most legumes and grains, but I’m not as strict with myself. You can easily incorporate paleo elements while eating a low-FODMAP diet. As with any diet, you just need to find what works for you.
Listen to your body. Your body constantly provides you with feedback so take a moment and observe. Monitor how you feel and take the cues from there. I’m sure we’re going to see a lot more of FODMAP in the near future. It’s making waves, you can be sure of that!
The following foods are high in FODMAPS and should be avoided
- Fruits: Apples, Apricots, Asian pears, Blackberries, Boysenberries, Cherries, Figs, Mangoes, Nectarines, Peaches, Pears, Persimmons, Plums, Prunes, Tamarillos, Watermelon, White Peaches
- Vegetables: Artichokes, Asparagus, Cauliflower, Garlic, Garlic Powder (in large amounts), Leeks, Mushrooms, Onions (red, white, yellow and onion powder), Scallions, Shallots, Snow Peas, Sugar Snap Peas
- Cereals and Grains: Bran (from wheat, rye or barley), Bread (from wheat, rye or barley), Breakfast Cereals, Granolas and Muesli (from wheat, rye or barley), Crackers (from wheat or rye), Pasta, Couscous, Gnocchi (from wheat), Wheat Noodles (chow mein, udon)
- Nuts: Pistachios, Cashews
- Milk and Milk Products: Custard, Ice Cream, Milk (cow’s, goat’s and sheep’s including whole, low-fat, skin, evaporated and condensed), Pudding, Soft Cheeses, Yogurt (cow’s, sheep’s or goat’s)
- Additives: Sweeteners and added fibre, fructo-oligosaccharides, high-fructose corn syrup, honey, inulin, isomalt, mannitol, polydextrose, sorbitol, xylitol
- Drinks: Chamomile and Fennel Tea, Chicory-based Coffee Substitutes, Juices made from unsuitable fruits
- Legumes: Beans (all kinds), Chickpeas, Lentils
The following foods are moderate in FODMAPS and therefore should be eaten in moderation
- Fruits: Cherries, Longans, Lychee, Pomegranate, Rambutan
- Milk and Milk Products: Cottage Cheese, Cream, Cream Cheese, Crème Fraiche, Mascarpone, Ricotta
- Nuts: Almonds, Hazelnuts
- Vegetables: Avocado, Beets, Broccoli, Brussels Sprouts, Butternut Squash, Celery, Corn, Fennel, Green Peas, Savoy Cabbage, Sweet Potato