Eating a bowl of porridge or slice of rye bread every day reduces a person's risk of developing type 2 diabetes, new research suggests.
Those who consume 50g of whole grains daily, whether it be wheat, oats, rye, rice or millet, are up to 34 per cent less likely to suffer from the condition, a study found.
Study author Professor Rikard Landberg, from the Chalmers University of Technology, Gothenburg, said: "Our results are in line with dietary advice, which recommends switching out foods containing white flour for whole grains.'
He adds those who follow a low-carb diet, such as the Atkins, miss out on whole grains' benefits, saying: "When it comes to whole grains, the research results are clear.
"Among the many studies which have been made, in varied groups of people around the world, there hasn't been a single study which has shown negative health effects."
The researchers analysed 55,465 people aged between 50 and 65 over 15 years.
At the beginning of the study, the participants completed a questionnaire about their diets.
From these questionnaires, they were divided into four groups according to the amount of whole grains they ate a day.
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Those with the highest intake consumed at least 50g daily, which is the equivalent of a portion of oatmeal or a slice of rye bread.
The results were linked to data from Denmark's national diabetes register to determine which of the participants developed type 2 diabetes.
Professor Landberg said: 'It is unusual to be able to investigate such a large range when it comes to how much wholegrain people eat.
"If you divided American participants into for groups, the group that ate the most wholegrain would be the same level as the group that ate the least wholegrain in Denmark. In Europe, Scandinavia eats the most, Spain and Italy the least."
Results suggest that the male participants who ate the highest amounts of whole grains a day were 34 per cent less likely to develop type 2 diabetes, compared to those with the lowest whole grain consumption.
Among women, the biggest whole grain consumers had a 22 per cent reduced risk.
For every whole grain serving, which is around 16g, the male participants' risk of type 2 diabetes declined by 11 per cent and the women's by seven per cent. It is unclear why whole grains benefit men more than females.
Professor Landberg said: 'When it comes to whole grains, the research results are clear: among the many studies which have been made, in varied groups of people around the world, there hasn't been a single study which has shown negative health effects.'
The findings were published in The Journal of Nutrition.