How to Reduce Bloating: A Root-Cause Approach

Bloating relief often starts with understanding the root cause. For most people, excess gas or fluid in the digestive tract — driven by specific foods, eating habits or hormonal changes — is responsible. Targeted dietary and lifestyle adjustments, where appropriate guided by a qualified professional, may help support more comfortable digestion day to day.

What is bloating, and why does it happen?

Bloating is the sensation of a full, tight or visibly swollen abdomen — and it is far more common than most people realise. Approximately 1 in 7 adults globally experience irritable bowel syndrome (IBS), with bloating consistently reported as one of its most distressing symptoms, according to Monash University researchers who developed the widely studied low FODMAP dietary approach.

The mechanism behind bloating is largely one of gas accumulation. The digestive tract naturally produces gas as a by-product of bacterial fermentation, but when gas builds up faster than it can be expelled — or when the gut wall is sensitised — the resulting pressure creates that uncomfortable feeling of fullness or visible distension.

At the centre of this process are FODMAPs: Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. These are short-chain carbohydrates found across many everyday foods that are not fully absorbed in the small intestine. Instead, they draw water into the bowel and are fermented by bacteria in the large intestine, producing gas that distends the bowel wall. For people whose gut is sensitised — as is often the case in IBS — even modest amounts of gas can feel amplified. For others, fluid retention, hormonal shifts or constipation may be the primary driver. Understanding which mechanism is most relevant to you is the first step toward meaningful, lasting bloating relief.

Which foods are most commonly linked to bloating?

Several food groups are well recognised in NHS guidance as likely contributors to bloating and wind — and most of them are foods many of us eat every day.

The NHS identifies the following as gas-producing foods that may contribute to bloating:

• Cabbage, broccoli, cauliflower and Brussels sprouts
• Beans and lentils
• Onions and garlic
• Fizzy drinks and carbonated water
• Alcohol and caffeinated drinks (particularly more than three cups per day)
• Processed and fatty foods
• Products containing the sweetener sorbitol, including some sugar-free sweets, chewing gum and low-calorie drinks

For people who experience IBS-type bloating, the NICE CG61 guideline — the UK’s primary clinical guideline for IBS in adults — also recommends limiting fresh fruit to approximately three portions per day, and the British Dietetic Association (BDA) echoes this guidance in their January 2025 Food Fact Sheet on IBS and diet.

It is worth noting that these foods are not harmful in themselves, and many are nutritionally valuable. The goal is not to remove them permanently, but to identify whether they are contributing to your symptoms — ideally with professional support rather than unnecessarily restricting your diet long term.

How you eat matters: the role of swallowed air

One of the most overlooked contributors to bloating is not what you eat, but how you eat it. Swallowing excess air — a process known as aerophagia — can cause gas to accumulate in the upper digestive tract, leading to belching and abdominal discomfort that may be mistaken for food-triggered bloating.

Common habits associated with aerophagia include:

• Eating quickly or on the move
• Talking while eating
• Chewing gum or sucking on hard sweets
• Drinking through straws
• Smoking

The NHS recommends eating with the mouth closed, chewing thoroughly and taking time over meals as practical steps that may help support more comfortable digestion. These changes cost nothing and require no dietary restriction — yet for some people, addressing aerophagia alone produces a noticeable difference in day-to-day symptoms.

The gut-brain connection: stress, activity and eating patterns

The relationship between stress and digestive comfort is well established — and it runs in both directions. The gut and brain are in constant communication via what is known as the gut-brain axis: a two-way network of nerves, hormones and immune signals that links psychological state directly to gut function.

When the nervous system is in a heightened stress state, gut motility can be affected — meaning food and gas move through the digestive tract more slowly or erratically. This can contribute to the build-up of gas and the sensation of bloating. NICE CG61 specifically advises that people with IBS be encouraged to identify and protect regular relaxation time, and to have their physical activity levels assessed as part of a holistic approach to symptom support.

Practical steps that may be worth considering alongside dietary changes include:

• Eating smaller, more frequent meals rather than large meals — as the NHS bloating guidance recommends
• Avoiding large meals late in the evening, which may disrupt normal gut motility overnight
• Building regular, gentle physical activity into your week, which may help support normal digestive function
• Creating space for genuine rest and relaxation, particularly during periods of high demand

These are not quick fixes, but they form an important part of a root-cause approach to bloating that goes beyond simply removing foods from your plate.

Does fibre help or worsen bloating? (It depends on the type)

Fibre is often recommended for digestive health in general terms — but when it comes to bloating, the type of fibre matters enormously.

Insoluble fibre, most notably wheat bran, can worsen bloating and wind in people who are sensitive to it. NICE CG61 specifically discourages high-insoluble-fibre intake for people with IBS who experience bloating and wind — a finding that may surprise those who have been advised simply to “eat more fibre.”

Soluble fibre, by contrast, is generally better tolerated. The following sources are suggested in NHS and NICE guidance for people who experience bloating and wind:

• Oats: a versatile, accessible soluble fibre source
• Linseeds (flaxseeds): up to one tablespoon per day, taken with at least 150 ml of fluid — the fluid is important, as linseeds absorb water and can cause discomfort if taken without adequate liquid
• Ispaghula husk: a soluble fibre supplement that may be recommended by a pharmacist or GP in some cases

Crucially, any increase in fibre intake should be introduced gradually. Adding too much too quickly — regardless of the type — may temporarily worsen bloating as the gut microbiome adjusts. A slow, steady increase gives the digestive system time to adapt.

What is the low FODMAP approach, and could it help?

The low FODMAP approach is currently the most extensively studied dietary intervention for bloating associated with IBS. Developed by researchers at Monash University in Australia, it involves temporarily reducing foods high in certain fermentable carbohydrates — the FODMAPs — to identify which specific types are contributing to symptoms.

Monash University’s research indicates that approximately 75% of people with IBS — around 3 in 4 — experience meaningful symptom improvement on the low FODMAP approach, typically within two to six weeks of the elimination phase. For anyone experiencing significant, persistent bloating, those figures make it a genuinely important option to know about.

However, both the BDA (January 2025) and NICE CG61 position the low FODMAP approach as a second-line dietary step — one to consider when first-line changes to eating habits and food choices have not provided sufficient relief. Both also emphasise that it should be undertaken with guidance from a healthcare professional with expertise in dietary management, not as a self-directed DIY elimination diet.

There are good reasons for this recommendation. The elimination phase is nutritionally complex: many high-FODMAP foods are rich in prebiotic fibres that feed beneficial gut bacteria, and removing them indiscriminately — without a structured reintroduction phase — risks both nutritional gaps and an unnecessary long-term restriction of foods that may not actually be problematic for you as an individual. A structured, professionally guided approach allows you to identify your specific trigger foods and build a long-term eating pattern that is both comfortable and nourishing.

If you are exploring this approach, our IBS support page has further information on how we work with clients experiencing gut symptoms.

Hormonal bloating: a specific consideration for women

If you notice that bloating follows a cyclical pattern — worsening in the days before or during your period — hormonal fluctuations may be a significant contributing factor. The NHS bloating guidance explicitly recognises hormonal changes around menstruation as a common and recognised cause of bloating.

This type of bloating is physiologically driven: fluctuations in oestrogen and progesterone across the menstrual cycle can affect gut motility and water retention, producing the familiar pre-menstrual abdominal heaviness. It is distinct from food-triggered bloating in its pattern, and dietary changes alone may have a more limited effect on cyclically driven symptoms.

If you suspect hormonal fluctuations are a primary driver, it may be worth tracking your symptoms across your cycle to identify the pattern — and discussing this with your GP or a qualified nutritional therapist who can consider the wider hormonal picture alongside gut function.

When should bloating prompt a GP visit?

For most people, occasional bloating after a gas-producing meal or during a stressful period is a normal part of life. However, there are circumstances where bloating warrants a prompt conversation with your GP — not to cause alarm, but because persistent or unexplained bloating can occasionally be a signal that something needs further investigation.

The NHS advises speaking with your GP if bloating:

• Has persisted for three weeks or more without a clear cause
• Is accompanied by unexplained weight loss
• Occurs alongside blood in your stools
• Is associated with a change in bowel habits that is new and unexplained
• Comes with persistent pelvic or abdominal pain
• Is accompanied by changes in how often you urinate, or difficulty urinating

Cancer Research UK notes that persistent bloating — particularly abdominal bloating that does not go away, increased abdominal size, or bloating accompanied by pelvic pain or loss of appetite — can be a symptom of ovarian cancer, though it is important to emphasise that this is rare and that the vast majority of people experiencing bloating have a far more straightforward cause. The key message is: if bloating is persistent, frequent, and not explained by diet or lifestyle, please see your GP. Early investigation is always the right step.

Seek urgent medical attention if bloating is sudden and severe, or is accompanied by significant abdominal pain.

This article is for general education and is not medical advice. Nutritional therapy supports general health and wellbeing; it is not a substitute for medical care, and we do not diagnose, treat, cure or prevent any disease.