10 Foods to Avoid if You're on a Low FODMAP Diet
Onions are another concentrated source of fructans.
Similar to garlic, onion is commonly used to flavor a wide range of dishes, making it difficult to restrict.
Shallots are one of the highest sources of fructans, while a Spanish onion is one of the lowest sources (6).
While different varieties of onions contain different amounts of FODMAPs, all onions are considered high-FODMAP.
Summary: Different onion varieties contain different amounts of FODMAPs, but all onions are considered to contain high amounts.
But interestingly, not all fruits are considered high in FODMAPs. This is because some fruits contain less fructose than others.
Also, some fruits contain high amounts of glucose, which is a non-FODMAP sugar. This is important because glucose helps your body absorb fructose.
This is why fruits that are high in both fructose and glucose do not typically cause gut symptoms. It's also why only fruits with more fructose than glucose are considered high-FODMAP.
Nevertheless, even low-FODMAP fruits can cause gut symptoms if they're consumed in large quantities. This has to do with the total fructose load in your gut.
Therefore, sensitive people are encouraged to only eat one portion of fruit per sitting or approximately 3 ounces (80 grams).
High-FODMAP fruits include: Apples, apricots, cherries, figs, mangoes, nectarines, peaches, pears, plums and watermelon (7).
Low-FODMAP fruits include: Bananas, blueberries, kiwi, limes, mandarins, oranges, papaya, pineapple, rhubarb and strawberries (7).
Please note that this is not an exhaustive list. Other lists can be found here.
Summary: All fruits contain the FODMAP fructose. However, some fruits have less fructose and can be enjoyed in single portions throughout the day.
Some vegetables are high in FODMAPs.
In fact, vegetables contain the most diverse range of FODMAPs. This includes fructans, galacto-oligosaccharides (GOS), fructose, mannitol and sorbitol.
Furthermore, several vegetables contain more than one type of FODMAP. For example, asparagus contains fructans, fructose and mannitol (7).
It's important to remember that vegetables are part of a healthy diet and there is no need to stop eating them. Instead, simply switch out high-FODMAP vegetables for low-FODMAP ones.
Summary: Vegetables contain a diverse range of FODMAPs. However, many vegetables are naturally low in FODMAPs.
6. Legumes and Pulses
Legumes and pulses are notorious for causing excess gas and bloating, which is partly attributed to their high FODMAP content.
The key FODMAP in legumes and pulses is called galacato-oligosaccharides (GOS) (4).
The GOS content of legumes and pulses is affected by how they are prepared. For instance, canned lentils contain half the GOS that boiled lentils do.
This is because GOS is water-soluble, meaning some of it leaches out of the lentils and into the liquid.
Nonetheless, even canned legumes are a significant source of FODMAPs, though small portions (typically 1/4 cup per serving) can be included in a low-FODMAP diet.
Legumes and pulses are good sources of protein for vegetarians, but they are not the only choice. There are many other low-FODMAP, protein-rich options.
High-FODMAP legumes and pulses include: Baked beans, black-eyed peas, broad beans, butter beans, chickpeas, kidney beans, lentils, soybeans and split peas (4).
Low-FODMAP, vegetarian sources of protein include: Tofu, eggs and most nuts and seeds.
Summary: Legumes and pulses are notorious for causing excess gas and bloating. This is related to their high FODMAP content, which can be altered by how they are prepared.