Our Dietitian explains how to enjoy beans without the discomfort

Beans are brilliantly nutritious. They are rich in plant protein and fibre, and are a good source of iron, folate, B vitamins, magnesium and zinc. There are plenty of reasons to eat more beans. Despite these benefits, on average, we only eat one portion of beans a week, and more than 40% of UK adults don’t eat beans at all.

Do beans cause gas and bloating?

One barrier to eating more beans is experiencing gut symptoms like bloating and gas. So why does this happen, and what (if anything) can you do about it?

First, some gas production is a normal part of digestion. It happens when your gut microbes ferment fibres in food that you don’t digest.

As they do this, they produce gas as a by-product, alongside short-chain fatty acids that help keep the gut environment healthy.

Beans in particular are rich in fermentable fibres called galactooligosaccharides (GOS). When gut microbes break down this fibre for energy, it supports the growth of beneficial bacteria. But the gas produced during this process can lead to feelings of bloating.

Research shows that the sensations of gas and bloating people feel after eating beans vary a lot. People with irritable bowel syndrome (IBS) are more sensitive to gas in the gut, making them more likely to notice gas, bloating and pain.

What can you do if beans make you bloat?

If gas and bloating are bothering you when you eat beans, there are a few tried and tested techniques that can help:

1. Try canned beans, and rinse before eating

This can make a difference because oligosaccharides leach into the canning liquid. So, draining and rinsing them before eating can help remove some of the 'gassy' component.

If you’re using dried beans, soaking and rinsing them before cooking can also help reduce their fermentable content.

2. Include beans in smaller portions

When it comes to tolerating beans, portion size matters. Smaller servings usually cause fewer issues because they contain lower levels of those fermentable fibres.

I usually suggest starting with two tablespoons of beans in a meal as a guide. But if you haven’t eaten beans in a long time, begin with one tablespoon and increase gradually after a week or two.

If you have IBS and follow a low FODMAP diet, here are the typical low FODMAP serving sizes - all are canned and drained:

Butter beans – 3 tbsp (53g)
Black beans – 2 tbsp (45g)
Cannellini beans – ⅓ cup (76g)
Chickpeas – 5 tbsp (80g)

3. Include beans often

If beans make you bloat, you’ll likely give them a wide berth. But there’s some evidence that eating them regularly may help improve tolerance over time.

One study found that people who added half a cup of beans to their daily diet noticed an initial increase in gas and wind, but this returned to normal after a few weeks.

One possible reason for this is an increased diversity of gut microbes. When you eat beans regularly, you are repeatedly feeding the microbes that specialise in fermenting bean fibre. Over time, you gradually grow more of the bacteria that are good at breaking these fibres down. As those microbes increase in number, the uncomfortable side effects may settle.

The key is starting small – for example, with a tablespoon of beans a few times a week – and sticking with it, gradually increasing over time.

If you are interested in learning more about why you should eat more beans, read our blog.