Local schoolchildren are choosing thin friends over plumper ones, according to a Baptist University study - and an expert says it is because they are choosing more western ideals. A total of 194 normal-weight and overweight children aged 10 to 12 from two primary schools were quizzed over their own body perceptions and how they saw and rated others. This study follows the release of data in February by Baptist University which estimated that 18.4 per cent of primary and secondary students in Hong Kong in 2005-06 were overweight - 3.4 per cent more than a decade earlier. Patrick Lau Wing-chung, associate professor in the department of physical education at Baptist University, said the survey had concluded that overweight children were already suffering in their social relationships. 'Results indicate that a westernised pattern of a thin body ideal has pervaded into Chinese children's minds,' he said. 'When choosing friends, they naturally reject fat children. They want to make friends with average or underweight people.' Professor Lau believed the body image here was still not as serious as in the United States or Britain, and that re-educating children to accept various body sizes might help change attitudes. Studies have shown that being fat is the No1 reason for peer rejection in children in the US. Mike Cheung, of the department of psychology of the National University of Singapore, helped Professor Lau analyse the test results. As thin children choose the physically fit as their friends, fatter children feel less attractive, and so tend to have difficulty in making friends and isolate themselves, Professor Lau said. But he said he was surprised the study showed not only thin people discriminated against fat children, but overweight youngsters discriminated against others who were fat. The study also showed that thinner people believed they were fitter than those who were heavier, he said. 'Students who are currently satisfied with their own body weight have the highest body attractiveness perception. They do not want to lose or gain weight,' he said. Professor Lau added that Hong Kong children accurately perceived their body weight much better than British children, who tend to overestimate their body weight. He suggested that children should be re-educated to accept different body sizes so they will learn that 'variety is OK. We have a range of body types, not only thin is good'. 'We [should] teach children to value friends for their personality, not appearance and to avoid fat-labelling,' he said. Fat children are often teased and perceived to be 'lazy, dirty, lying, stupid, mean, ugly', he said. The proportion of obese children here is higher than in South Korea (11.4 per cent), Taiwan (15 per cent), Japan and Singapore (10 per cent). The mainland estimated 25 per cent of its children were obese, with body mass indexes over 30 in 2002. The World Health Organisation has said childhood obesity can lead to premature deaths, chronic diseases and poorer quality of life.