A student who weighs just four stone has told how she must eat up to 60 meals a day to stay alive.Lizzie Velasquez has a rare and undiagnosed syndrome that prevents her from putting on weight.She has to eat every 15 minutes and consumes up to 8,000 calories every day.Despite her huge intake, the communications student from Austin, Texas, has never tipped the scales over 4st 3lbs.Source: Sky News