Parents who are overweight are being warned that their unhealthy lifestyles are encouraging the same behaviour in their children, and putting them at a higher risk of obesity and ill health later in life.
In a recent study, researchers from Arizona State University found that children who copied their parents' sedentary lifestyles which were dominated by watching television and playing computer games were 33.3 per cent more likely to become overweight or obese as young adults.
The researchers examined approximately 6,400 children in 1995, and then again in 2001-2002.
Their results revealed that even those children who did not engage in high levels of physical activity, but rather kept themselves busy with other activities such as part-time jobs or school clubs, were less likely to become obese.
Around 15 per cent of youngsters aged 12 to 19 in the US are currently overweight or obese - an increase of a third since the 1970s.
However, obesity levels in British children aged two to ten have also risen sharply, to 13.7 per cent in 2003.
Lead author Ashley Fenzl Crossman said overweight parents not only passed on their genes to their children, but also their bad habits.
"Our research suggests that prevention must begin at home," she said.
Ms Crossman concluded: "Parents and other caretakers should be urged to exert control over childrens diets, including making a healthy breakfast a priority, and to limit the amount of free time that children have to spend on sedentary activities."