Eating chips during pregnancy can lead to significant health problems for new born babies, research suggests.
Consuming a vast quantity of chips, crisps and biscuits during pregnancy can lead to babies having a lower than average birth weight, the study found.
Mothers-to-be who have a high intake of acrylamide - which is found in commonly consumed foods and coffee - are also more likely to have a baby which has a smaller head circumference.
The size of a child's head has been associated with delayed neurodevelopment while lower birth weights have been associated with adverse health effects in early life and as children grow up.
Babies born to mothers with a high dietary intake of acrylamide were found to be up to 132 grams lighter than babies born to mothers who had a low intake, researchers said. The mean birth weight among children who were exposed to the highest levels of acrylamide compared with children in the lowest was around 100 grams, the authors said.
The effect caused by acrylamide is comparable to lower birth weights caused by maternal smoking, they said. The infant's heads were also up to 0.33 centimetres smaller, they found.
Acrylamide is a chemical which is produced naturally in food as a result of cooking starch-rich food at high temperatures, such as when baking or frying. It has been found in a wide range of home-cooked and processed foods including crisps, chips, bread and coffee.
"The potential public-health implications of our findings are substantial," the authors said. "Increases in head circumference are an important indication of continued brain growth, and reduced birth head circumference has been associated with delayed neurodevelopment.
"Reduced birth weight is a risk factor for numerous adverse health effects early in life, and has been associated with multiple adverse outcomes later in life such as reduced stature, increased incidence of cardiovascular disease, type 2 diabetes mellitus, and osteoporosis."
They added: "These findings provide evidence supporting the need for changes in food production and for providing clear public health advice to pregnant women to reduce their dietary intake of foods that may contain high concentrations of acrylamide."
Researchers examined the diets of 1,100 pregnant women between 2006 and 2010 in Denmark, England, Greece, Norway and Spain. They used food-frequency questionnaires on mothers and also examined each baby's cord blood - which provides information about levels of acrylamide exposure during the last months of pregnancy.
The programme is one of the country's biggest research projects, studying the health of around 14,000 children born in the city.
Dr Laura Hardie, reader in molecular epidemiology at the University of Leeds, said: "186 women from the Born in Bradford study took part in this major European research programme. We found that their babies had the highest levels of acrylamide out of all of the five centres, almost twice the level of the Danish babies.
"When we investigated their diet it was clear that the largest source of dietary acrylamide is from chips."
CREAL researcher and lead author Dr Marie Pedersen, added: "The public-health implications of the findings in this study are substantial.
"Reduced birth weight, in particular low birth weight, has been shown to be related to numerous adverse health effects early or later in life such as cardiovascular disease and diabetes. Furthermore, reduced birth head circumference has been associated with delayed neurodevelopment."
Professor John Wright from the Bradford Institute for Health Research, who is leading the Born in Bradford study, added: "This is important new research which demonstrates a clear link between acrylamide and the health of newborn babies.
"The effect of acrylamide is comparable with the well-known adverse effect of smoking on birth weight. Our advice for pregnant mothers is to follow a balanced diet and go easy on the crisps and chips.
"The results provide further evidence about the potential toxicity of acrylamide and should also encourage food manufacturers to start exploring methods to reduce acrylamide in their products."