Children whose parents separate have a significant risk of increased weight gain, according to a recent U.K. study—a risk that only gets worse with time.

The study, which was published last week, studied the BMI (body mass index) and rates of obesity of more than 7,500 U.K children at different points in their life from 9 months old to 11 years old.

It looked at children in both households that went through a separation and households where the parents stayed together.

“To conduct a study like ours, we need to follow a large group of children,” said Berkay Ozcan, one of the study’s authors, in an interview Wednesday on CTV News Channel. “(Who are) going through at the same ages and same stages over time. When you compare … a group of children who experience a parental divorce versus not, it’s kind of compounding what the affects of divorce (are).”

Although the study found that there were no notable increases in children’s weight leading up to a divorce, or in the immediate aftermath of one, if children experience a parental separation they have a much higher chance of becoming overweight or obese in the long run, compared to their peers in households with parents who were still together.

Ozcan, who is a social policy professor at the London School of Economics and Political Science, said there were a variety of factors that contributed to this.

Some of it was down to how much time a parent could have to dedicate to their child’s eating habits when there are no longer two parents in the household to divide the work.

“(A) single father or single mother might have less time to buy fresh fruits or cook healthy foods at home,” Ozcan said. There may be less money flowing into the household, and extracurricular activities for children, such as sports, could be no longer affordable as well.

And with such a dramatic change in a child’s life—a change that could include moving to a new home, school or town—emotional struggles could manifest in eating disorders, Ozcan said.

Obesity is not the only way weight can negatively impact a person’s health, but the study found that on the whole, children in the U.K. were more likely to suffer weight gain rather than weight loss as a result of the instability produced in their lives by a parental separation.

Weight gain is especially likely to occur if a parent’s divorce occurred before the child reaches 6 years old, “because these are (the) most crucial ages for the growth,” Ozcan said.

Although not the first study to look at the impact of parental separation on children’s weight, the study says it the first one with a focus outside of the United States.

In closing, the study highlighted the need for parents to keep a close eye on their children’s health after a separation, pointing out that the issues were found to increase with time.

“Intervening early could help to prevent—or at least attenuate—the process that leads some children to develop unhealthy (eating patterns),” the study said.