One in three girls aged between 9 and 13 is overweight or obese, according to a new Australian study.
The new study found that girls as young as nine are 5-20kg overweight.
The findings revealed that at least 30 per cent of girls are overweight before they enter high school.
The study added that the 'muffin-top' tweens are wearing their food choices on their waistlines, setting themselves up to be overweight as adults and suffer major health problems such as infertility.
Health experts have warned that the sensitive issue could no longer be ignored.
"It is a particular age group that has been overlooked and there needs to be more focus because they are much more in control of their food choices," the Daily Telegraph quoted Associate Dean of Clinical and Molecular Medicine at Flinders University Professor Lynne Cobiac as saying.
"If they are overweight now, most, but not all, will often go on to be overweight when they are adults and they could develop diabetes, heart disease and even cancer.
"It's really important that we understand what is influencing their choices so we can help them to be healthy, and set them on the right path," Cobiac added.
The study showed that girls, by age 12, are doing almost no exercise and piling on pounds.
However, as they grow older, girls become more body conscious, restricting meals or overeating and developing disorders.