As a specialist gastrointestinal dietitian, one of the most common complaints we see in clients is abdominal bloating. This symptom usually refers to physical distension, but can also include a full and uncomfortable sensation after meals, even when not overindulging. Commonly, we hear comments from such clients along the lines of ‘I look six months pregnant by the end of the day!’

Bloating is often associated with abdominal pain, altered bowel habits and lethargy. It can also make people feel extremely self-conscious, which can even result in restricting their participation in desired activities.

What are the causes of bloating?

There are a range of potential causes of abdominal bloating. Such triggers can include:

• hormonal fluctuations (affecting the smooth muscles which line the gut)
• stress (through its effect on the brain-gut axis)
• altered muscle function (of pelvic floor and diaphragm)
• foods and food intolerance reactions (discussed in more detail below).

If you suffer from bloating, it’s vital that you don’t self-diagnose, but instead discuss this symptom with your doctor. Bloating can also be the outer manifestation of undiagnosed coeliac disease, inflammatory bowel disease (for example, Crohns and colitis), or more sinister issues such as bowel and ovarian cancer. Bloating can also be a common symptom of Irritable Bowel Syndrome (IBS), a functional gut disorder affecting up to one in seven people. Your GP can assist you, and arrange any screening tests and referrals needed, to rule out these conditions.

Common food triggers for bloating

Processed, sugary and fatty foods are often blamed for bloating, and there are a number of reasons why they may be problematic, for example:

Fatty foods take a lot of work to digest and can slow our gut transit time, exacerbating distension and discomfort. Some people are more sensitive to the fat content of meals than others. 

Similarly, sugary foods such as soft drinks, baked goods, chocolate and lollies can be problematic in large doses. This may be in part due to an overload of fructose, which, if not well absorbed, will then be rapidly fermented in the large bowel, resulting in gas and distension. Sugary foods often also come with a host of additives (natural or added flavours, colours and preservatives). In some food sensitive individuals, these dietary compounds can seem to affect the tone of smooth muscle and behaviour of the gut nervous system. 

FODMAPs in foods

Surprising to many, is that ‘healthy foods’, such as certain fruits, vegetables, nuts and grain products, can exacerbate bloating. This is because they contain a range of wind-producing, or ‘fermentable’ carbohydrates, referred to as FODMAPs. Common culprits are the onion and garlic family, wheat breads, pasta and cereals, legumes and certain fruits and vegetables.

In some individuals, lactose (the natural sugar in milk, yoghurt and ice cream) will lead to bloating and other gut symptoms. Fructose (found in all fruits, but in higher concentrations in foods such as mango, apple, pear, dried fruits and honey) is another naturally occurring sugar that can lead to fermentation and bloating.

The table below is a brief list of foods with higher FODMAP levels, which can be problematic.

FODMAP table

As you can see, most of the foods in the high FODMAP table are really good for us. There is a great deal of variation between individuals in their tolerance to these sugars, and dosage is usually key. For example, combining many high FODMAP foods in one meal may be a problem, but small to moderate amounts of higher FODMAP foods in a sitting may be tolerated well.

Managing food intolerance and identifying your triggers can be a tricky business. It is highly recommended to consult an experienced dietitian who can help you control symptoms while still eating a balanced diet, enjoying food, and not being overly restricted.

What else can you do about bloating?

If you are experiencing bloating, make sure you have your symptoms checked by a doctor. You may also benefit from seeing:

• a specialist physiotherapist, who can assess your pelvic floor and abdominal muscle strength and functioning, and prescribe exercises to help
• a psychologist or counsellor, to assist with managing stress and anxiety.

Quick dietary tips to reduce the bloat

• Reduce meal sizes and spread intake over the day
• Reduce excessively fatty foods such as deep fried items and creamy sauces
• Moderate your intake of sugary, highly processed foods such as soft drink, cakes, biscuits, chocolate and lollies
• Trial a lower FODMAP diet (reducing foods such as onion, wheat products, legumes and certain fruits and vegetables)
• See an experienced dietitian, who can offer support, guidance and practical suggestions for your diet

By Guest Author Marnie Nitchke, APD

Marnie is a dietitian and offers the expertise to help with bloating, gastrointestinal symptoms, as well as individualised dietary advice.