Why am I bloated? Dietitians explain the reasons for your uncomfortable stomach
Do you regularly experience a swollen abdomen? We ask the experts what causes our waist size to go up and down (and how to prevent it)
It’s a common problem that can cause discomfort, pain and embarrassment. But while some people only experience bloating now and then, others are all too familiar with having to loosen their waistbands as their stomach starts to swell.
According to the NHS, symptoms of bloating include your tummy feeling full or bigger than usual, having stomach pain or discomfort, rumbling or noises in your stomach and farting more than usual.
So what causes it and what can you do about it? We asked two experts, Kirsten Jackson, a consultant gastroenterology dietitian aka the “IBS dietitian”, and Dr Linia Patel, a dietitian and performance nutritionist, to explain all.
Do any particular foods cause bloating?
Linia: Being a little bloated after a meal is normal. Some people experience more bloating after eating certain foods that contain higher amounts of non-digestible or poorly digestible compounds called FODMAPs. FODMAPs stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols.
The undigested fibre and sugars in FODMAP foods end up in your large intestine where bacteria ferment them, leading to increased gas.
Conditions like IBS (irritable bowel syndrome) or small intestinal bacterial overgrowth (SIBO) are particularly sensitive to vegetables including broccoli, cauliflower, cabbage or brussels sprouts; fruits such as apples, pears, peaches and prunes; legumes and pulses; sugar alcohols and artificial sweeteners found in diet products; carbonated drinks and dairy products high in lactose, such as milk.
Can alcohol cause bloating?
Kirsten: Many alcoholic drinks, including cocktails, beer and some sugar-free mixers, contain high levels of FODMAPs which can result in bloating.
Alcohol can also have an indirect impact on bloating by impacting sleep quality, and poor quality sleep worsens digestive symptoms.
Linia: Excessive alcohol can cause damage to the protective mucus that lines the intestine, making your intestine “leakier” and promoting inflammation. The key is to keep within the recommended 14 units per week.
What role does gut bacteria play in bloating?
Kirsten: Gut bacteria plays an important role in the body, including digesting carbohydrates so that we can absorb them.
This process is known as fermentation, but the byproduct is gas, so if this process is overactive or you eat a large portion it could result in bloating.
Women seem to report regular bloating – why is that?
Kirsten: Women’s fluctuating hormones is one reason why they experience bloating. Body temperature increases slightly during ovulation, which can reduce your quality of sleep. Progesterone, which rises before your period starts, is associated with constipation and during perimenopause, oestrogen levels can become more erratic and higher oestrogen levels can lead to more water retention, leaving you feeling bloated.
Linia: The female colon is 10cm longer than a man’s so it can take women an extra 14 hours to move food through the large intestine. Women also have a relaxed abdominal wall to allow for pregnancy, while men have a strong abdominal wall which better holds their bowel in place.
How does eating salt contribute to bloating?
Linia: Research suggests there is a link between sodium intake and bloating due to the water retention that reduces gut motility. Sodium is found in salty foods such as cured and smoked meats, canned foods and sauces.
When should you consult your GP about bloating?
Kirsten: See a GP if you are bloating regularly, even if it isn’t “that bad”, as it can be a symptom of other conditions including ovarian cancer. If it is persistent, get it checked out.
Linia: If you experience anything out of the ordinary: excessive farting (more than 20 times a day) and chronic bloating with pain and discomfort – and it doesn’t respond to lifestyle changes – seek support from a health professional.
IBS is a common cause of bloating. How do you know if you have IBS and how can you treat it?
Kirsten: Symptoms of IBS can cross over with other conditions like coeliac disease and even certain cancers, so do see your GP. To 'qualify' as having IBS, your symptoms must have been going on for three months, and occur at least one day per week. Once diagnosed, you may need specialist help from a registered dietitian to help navigate more complicated topics like pin-pointing your food intolerances safely and navigating fibre. You may also need mental health support from a therapist or medication from your doctor.
Linia: IBS is a functional gastrointestinal disorder characterised by irregular bowel habits (diarrhoea and/or constipation), bloating and flatulence and cramps. It’s exact cause is unknown but stress, impaired gut-brain communication, mental health and “bad” gut bacteria may be factors.
Doctors can’t test to confirm IBS; they diagnose IBS by ruling out other conditions. A low-FODMAP diet has been shown to improve symptoms but it can be very restrictive and it’s best to work with a nutrition expert to ensure you are able to maintain a balanced diet.
What lifestyle changes can you make to prevent or beat bloating?
Kirsten: Avoid large portions. We often just eat too much, which can lead to feeling uncomfortable with a distended stomach. Drink regularly, sipping rather than gulping. Avoid chewing gum, get eight hours of good quality sleep and move daily (gardening and walking count).
Linia: Keep a food and symptom diary to help identify the trigger for your bloating and excessive flatulence. It’s also a useful tool to take to a dietitian appointment. Go to the loo regularly – passing stools can relieve some of the gas from your gut; wear loose clothes which don’t add pressure to the abdomen; and aim to eat the recommended 30g of fibre a day, increasing gradually and upping water intake at the same time.
Some studies suggest that probiotics may aid digestive symptoms by boosting the number and types of bacteria in your gut, but you need to take them for four weeks and they don’t work for everyone.