Teenage girls' obsession with slim celebrities such as Britney Spears and Victoria Beckham is leading them into yo-yo dieting that could endanger their health, according to Ulster University research.
Elaine Mooney, a doctoral student, who interviewed more than 120 14 to 16-year-olds in the Republic of Ireland, said girls' typical comments included: "If Britney Spears was fat, no one would buy her CDs."
She found that the girls felt under pressure to model themselves on celebrities even when they disliked the way they looked. One teenager remarked paradoxically: "Victoria Beckham is disgustingly thin - her head is too big for her body - although I wouldn't mind looking like her."
Ms Mooney presented her findings this week at the International Consumer Science Congress in Kyoto, Japan. She called for nutritional health promotion to be targeted specifically at teenage girls to encourage them to eat healthily and to develop a positive body image.
Girls in her study equated thinness with success and glamour and often indulged in "binge dieting", starving themselves for two or three days before the weekend.
Ms Mooney's supervisor, Chris Strugnell, senior lecturer in consumer sciences at Ulster, said the teenagers were falling into bad habits that would be hard to shift. A number of girls said they had been dieting since they were 12, although one admitted: "Diets don't seem to work."
Adolescent girls, who get plumper as they go through puberty, need a good intake of calcium and iron, which they could miss if they followed restrictive diets, Dr Strugnell said.
Home economics teachers interviewed by Ms Mooney said they believed that many parents were unaware of their daughters' dieting. The girls would throw away packed lunches and buy something else.
An article based on the study is due to appear next month in a special issue of the International Journal of Consumer Studies .