ADOLESCENT boys eat junk foods rather than salads to impress their friends how macho they are, according to a survey of children's eating habits from the Institute of Food Research in Reading. Richard Shepherd, co-ordinator of the survey, says that for boys eating unhealthy foods was rather like riding motorbikes; rebelliousness did not include eating salads. 'Ringleaders', who are key opinion formers, might be the best targets for dietary advice he suggests in New Scientist.