British researchers found that excessive weight gain in children is the result of genetic peculiarities, rather than lifestyles.

More than 5,000 pairs of identical and non-identical twins were followed in the study conducted at University College London. The study revealed that body mass index was 77 percent determined by genes.

Parents alone are not to be blamed for a child's overweight. The child's genetic susceptibility plays an important role in excessive weight gain, according to Jane Wardle, University College London, who led the study. It does not mean that all children with a high complement of susceptibility genes will gain excessive weight, Wardle said. The genetic attribute gives them a stronger predisposition to gain overweight.

Overweight children are more prone to become overweight or obese in adulthood. They have an increased risk of cancers, heart disease and diabetes later in life, according to the researchers. Researchers said twin studies are effective in testing how far genes or environment influence the growth of a child. Identical twins carry the same genes, while non-identical twins have different genetic features. As identical twins are usually brought up in the same environment, they have similar upbringing in terms of food. So scientists can determine how far genes influence obesity and how much the environment is to be blamed. The study showed that influence of the genes was more marked in gaining overweight than the effect of a bad environment.