But they may nearly all be wrong – and staying away from bread could do more harm than good, a panel of experts has warned.
They argue that research has shown bread produces less bloating than pasta, and what makes us fat is not the sandwich, but the filling.
Moreover, while bread is often singled out as a bloating culprit, the evidence continues to show that this is more perception than reality.
The list of celebrities who refuse to touch gluten is long. Gwyneth won’t let it pass her lips and Madonna swears avoiding gluten is what keeps her young.
Although 98 per cent of Britons say they eat bread, many blame it for bloating and weight gain, and think they would be better off going gluten-free.
And while 20 per cent think it’s important to eat gluten and wheat-free, just 0.5 per cent of the population has gluten intolerance.
This means many could be losing out on vital nutrition such as fibre, iron and calcium by avoiding bread.
In fact, gluten free products can actually be higher in additives, saturated fat and sugar, Ayela Spiro from the British Nutrition Foundation, told a London conference of dieticians and nutritionists discussing bloating this month at King’s College London.
She also cited a new (as yet unpublished) study from the University of Bristol, which showed bread produced less physically measurable abdominal bloating than a pasta meal, despite diners saying they expected the bread would bloat them more.
Sue Baic, of the British Dietetic Association, added it is a common misconception that bread is fattening – ‘it’s what goes on the bread that is most harmful to our waistlines,’ she argued.
Two average slices of bread provide around 190 calories and 2g of fat, but spreading margarine or butter on them almost doubles the calories (334 calories) and adds 16g fat.
Furthermore, the nation’s favourite sandwich filling – egg mayonnaise – provides just under 600 calories and a huge 34g of fat, which is almost half the recommended daily intake for a woman.
Ms Baic added that many people assume white bread is bad for us, but this is not the case, saying: ‘The half and half types such as Hovis Best of Both, that look and taste like white but combine white and wholemeal flours can contain 75 per cent of the fibre content of wholemeal.’
‘As well as being a good source of calcium, iron and fibre, two slices of bread contain 20-30 per cent of our recommended nutrient intake of vitamin B1 [and other vital nutrients].
‘At just 5-10p per two slice serving it’s a very inexpensive way to get some good nutrition in your diet.’
So if it’s not bread that causes bloating, what does?
Gastroenterologist, psychotherapist and medical adviser to the IBS Network, Dr Nick Read said that ‘bloaters’ may just be more sensitive to the feeling of abdominal gas, but not actually produce more of it.
‘Possible risk factors for bloating include obesity, anxiety or depression, being inactive, constipated or premenstrual, and, in those with irritable bowel syndrome, eating too many fermentable carbohydrate sources in general, not just wheat,’ he added.
For example, some people with IBS may react with bloating on consumption of wheat but this is possibly more likely due to the presence of fructans found in many foods including onions, artichokes, asparagus and leeks rather than gluten, the panel concluded.