The research led by Dr Tracy Burrows of the University of Newcastle suggests that the obese and overweight kids are required to eat more fruit and vegetables to boost their antioxidant levels and lower the risk of diseases.
Previous studies have shown that high levels of carotenoids in the blood are associated with lower levels of disease.
Burrows believe that overweight and obese children could be chewing through their antioxidant carotenoids faster to counteract a higher rate of inflammation in their tissues.
If inflammation is increased in the obese and overweight children, it will be important to find ways of treating this, as inflammation is linked to increased risk of heart disease and cardiovascular disease, said Burrows.
"Fruit and vegetables are the only major source of carotenoids in the human diet, so if we measure that in the bloodstream then we're basically measuring their fruit and vegetable intake," ABC Online quoted Burrows as saying.
"They wouldn't be getting carotenoids from any other sources," she added.
In the study involving nearly 100 children, the researchers found that on average, overweight children had lower levels of carotenoids than children with a healthy weight and consumed the same amount of vegetables.
Obese kids also showed lower levels of carotenoids, the research revealed.
"There was a significant decrease in carotenoids the more overweight [the children] became," she said.
"We've come to the conclusion that overweight and obese children have higher requirements for carotenoids because they're using them up more," she added.