According to the World Health Organization, 39 million children were overweight or obese in 2020, leading to increased risks of heart disease, diabetes and an early death.
Ultra-processed foods, including packaged baked goods and snacks, fizzy drinks and sugary cereals, are commonly found in modern Western style diets and are associated with weight gain in adults.
The researchers drew on data for 19,958 children born to 14,553 mothers (45% boys, aged 7-17 years at study enrolment) from the Nurses’ Health Study II (NHS II) and the Growing Up Today Study (GUTS I and II) in the United States.
The NHS II is an ongoing study tracking the health and lifestyles of 116,429 US female registered 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.
A range of other potentially influential factors, known to be strongly correlated with childhood obesity, were also taken into account, such as a mother's weight (BMI), physical activity, smoking, living status (with partner or not), as well as children’s ultra-processed food consumption, physical activity and sedentary time.
Overall, 2,471 (12%) children developed overweight or obesity during an average follow-up period of four years. A 26% 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).
The researchers concluded the data “supports the importance of refining dietary recommendations and the development of programmes to improve nutrition for women of reproductive age to promote offspring health.”