Children whose mothers work long hours are more likely to become obese as they miss out on healthy meals, a new study suggests.
Researchers said that for every 10 hours a week a mother works, the weight of their children increases by on average one and a half per cent.
Childhood obesity has grown enormously since the 1960s with an estimated 14pc of boys and 17pc of girls aged two to 15 now obese.
The new research in America, where the problem is even more advanced, found that it was statistically connected to women going to work.
Researchers at American University, Cornell University, and the University of Chicago used data from the Study of Early Child Care and Youth Development, looking at 900 children who lived in 10 cities across the USA.
The researchers found that the total number of years mothers were employed had a small but cumulative influence on their children's weight lead to an increase in the likelihood of being overweight or obesity.
Every six months of work undertaken by a mother added approximately 1lb in weight to their child.
Surprisingly, changes in children's physical activity, time spent unsupervised, and time spent watching telly did not explain the link between maternal employment and children's weight.
And the time of day mothers worked was not significantly associated with children's weight.
The reasons for the findings are not entirely clear.
One possibility, according to the authors, is that working parents have limited time for grocery shopping and food preparation which may contribute to a greater reliance on eating out or eating prepared foods, which tend to be high in fat and calories.
The study was published in the journal Child Development.