Scientists are developing healthier bread to try to improve the nation’s health.
White loaves usually contain a type of starch that is digested too quickly, leading to dangerous spikes in blood sugar.
The more you eat, the more insulin the pancreas produces, potentially causing insulin resistance and type 2 diabetes. By being digested so quickly, white bread also fails to make the body feel full, which stops overeating.
A team at the Quadram Institute in Norwich is looking at creating starches that are digested more slowly and hope within ten years to have developed more nutritious white bread.
In the longer term they are examining the prospects of ‘personalised food’ to meet individual nutritional needs.
Lead scientist Richard Mithen said wheat, a major source of starch, provides a fifth of all the calories consumed in the world.
He said: ‘We have a very extensive programme to look at how we can make subtle changes to the starches in wheat.
‘We really need to do something about the burger bun.’
Both white and wholemeal bread contain starch, but white bread has a higher glycaemic index meaning it is digested more quickly.
Despite changes to dietary habits, demand for white bread still outstrips that for wholemeal bread. Professor Mithen said starch molecules in white bread and potatoes were shaped in branches, which made them easier to digest.
He added: ‘We’re looking at ways where we can have starch in a diet but it can be more slowly digested. One way you can do that is instead of having starch very branched, you have it much more linear. That means when you eat it it’s digested much more slowly.
‘Hopefully it would be just as delicious as you want bread to be. When you eat it, it may make you feel full a little bit quicker.
‘You wouldn’t get that big glucose rush after eating it.’
He said he thought that healthier wheat starch could be created through plant breeding rather than genetic engineering because certain wheat strains contained more linear starch.
Finding ways to alter the speed at which food is digested could lead to personalised nutrition, he added. The elderly need to digest food more quickly than the young, while athletes might benefit from rapid energy bursts and muscle-building nutrients.
Professor Mithen also expects foods to be designed around helping people with chronic diseases such as cancer and diabetes.
He said: ‘It’s not going to happen overnight, but in 20 years I expect there will be many more food products.
‘The science is very difficult and long term. It will work for some people and not for others.’