Constipation: good and bad food

Plant-based foods are a good place to start. A diet rich in fresh fruit and vegetables provides lots of roughage, and numerous other vitamins and minerals essential for a healthy body. Where possible, try them raw or steam rather than boil them, to keep them rich in other nutrients, although tinned and frozen are also fine for fibre intake. If they’ve got edible skin, leave it on, as often the skin is packed with fibre, vitamins and minerals.

Green vegetables are a good choice in particular, like:

• broccoli
• spinach
• potatoes with the skin on
• carrots with the skin on

Fresh fruits high in fibre content include:

• apples with skin on
• raspberries and blackberries
• figs

Dried fruits are effective, such as:

• prunes
• dried apricots
• dates

Legumes (plant food that grows in pods) or pulses (dried-out legumes) such as:

• broad beans, garden peas and runner beans
• lentils
• chickpeas
• kidney beans, black-eyed peas and even Baked Beans

Nuts and seeds can also be a good source of fibre, such as:

• almonds
• peanuts
• sesame seeds
• sunflower seeds

It’s also a good idea to swap white foods for brown foods, as their whiteness indicates the bran and roughage have been stripped out in processing to make them more palatable and visually appealing. Examples include:

• wholemeal or brown bread
• brown rice
• whole oats
• wholewheat pasta
• wholegrain cereals, instead of cornflakes or rice-based cereals
• wholegrains like buckwheat

Finally, you may see some processed foods with a label that says “fortified with fibre” - choose these over other options:

• certain breakfast cereals like Weetabix, Shredded Wheat or Muesli
• certain juices and smoothies - unsweetened and unprocessed are the healthiest options

As a general rule, you need about 30g of fibre a day, but many of us fall short of that. Aim for a varied healthy diet, adding some of the fibre-rich foods to your normal meals and snacks, like a handful of berries on healthy breakfast cereal, and substituting certain foods for an option with more roughage.

The British Dietetic Association suggests any food labels proclaiming 6g of fibre per 100g are "high in fibre”, and those with 3g or more are “a source of fibre”.

As a general guide 30g of fibre may be made up of the following options, with fibre per 100g:

• shredded wholewheat or bran cereals contain 13-25g
• two slices of wholemeal bread contain 7g
• boiled broccoli contains nearly 3g
• boiled parsnips contain 4.7g
• figs contain nearly 7g
• baked beans in tomato sauce contain nearly 7g
• boiled green beans contain 4g

You may see reference to soluble and insoluble fibre. We need a mixture, but soluble fibre is found in oats, fruit, vegetables, beans and pulses, and insoluble fibre is found in wholemeal bread and wholewheat cereals.

You may wish to reduce or leave out certain foods that can exacerbate constipation, particularly while you’re experiencing a bad episode. These include red meat, alcohol, and lots of caffeinated drinks like tea, coffee and cola. Highly processed “white” foods, processed microwaveable or frozen meals and fatty fast foods like chips and burgers are all ones to side-step.

It’s a myth that eggs and dairy products can cause constipation. They have lots of wholesome protein and nutrients in, so are good options for other aspects of your health, but they contain no fibre, so they won’t necessarily help constipation.

Bananas seem to have a constipation-promoting myth around them, but ripe bananas can be very helpful at shifting a blockage.

One exception to these rules is if you have IBS that tends towards constipation. You should keep a diary of foods and symptoms, and you may need specific dietary advice, especially to start a particular treatment diet called the FODMAP diet.

Those with gluten sensitivity may find cereals and wholegrains give them bloating and gas, so they may prefer sticking with fruit and vegetables to get their fibre. It's a personal choice.

Certain oils are known for promoting food through the gut, such as olive oil and flax seed oil.

Some studies have shown that probiotics may help constipation, but the evidence is mixed so far. If you want to try this, go for live yoghurt or other foods or supplements that contain Bifidobacterium lactis – give it at least 4 weeks to see if it’s helping. At the very least, it will help you on the way to a healthy gut by cultivating good bacteria in the microbiome, and it isn’t known to be harmful.