New York, A mother's consumption of ultra-processed foods appears to be linked to an increased risk of overweight or obesity in her offspring, irrespective of other lifestyle risk factors, says a new study.

According to the study, published in The BMJ, a 26 per cent higher risk was seen in the group with the highest maternal ultra-processed food consumption (12.1 servings/day) versus the lowest consumption group (3.4 servings/day).

"Mothers might benefit from limiting their intake of ultra-processed foods, and that dietary guidelines should be refined and financial and social barriers removed to improve nutrition for women of child bearing age and reduce childhood obesity," said researchers, including Yiqing Wang from Massachusetts General Hospital in the US.

Ultra-processed foods, such as packaged baked goods and snacks, fizzy drinks and sugary cereals, are commonly associated with weight gain in adults.

For the study, the team drew on data for 19,958 children born to 14,553 mothers (45 per cent boys, aged 7-17 years at study enrollment) from the Nurses' Health Study II (NHS II) and the Growing Up Today Study (GUTS I and II) in the US.

The NHS II is an ongoing study tracking the health and lifestyles of 116,429 US females registered as nurses aged 25-42 in 1989. From 1991, participants reported what they ate and drank, using validated food frequency questionnaires every four years.

The GUTS I study began in 1996 when 16,882 children (aged 8-15 years) of NHS II participants completed an initial health and lifestyle questionnaire and were monitored every year between 1997 and 2001, and every two years thereafter.

In 2004, 10,918 children (aged 7-17 years) of NHS II participants joined the extended GUTS II study and were followed up in 2006, 2008, and 2011, and every two years thereafter.

Overall, 2471 (12 per cent) children developed overweight or obesity during an average follow-up period of 4 years.

In a separate analysis of 2,790 mothers and 2,925 children with information on diet from 3 months pre-conception to delivery (peripregnancy), the team found that peripregnancy ultra-processed food intake was not significantly associated with an increased risk of offspring overweight or obesity.