Ananova:

Girls as young five have ideas about dieting and are conscious of their weight, a conference on child nutrition has been told.

New research presented to delegates also indicates parents should not pressure their children into eating certain foods and that environmental factors are more important than genetics in causing childhood obesity.

Professor Leann Birch, of Pennsylvania State University, told the Update on Childhood Nutrition Conference in Glasgow that 50% of a sample of five-year-old girls interviewed in central Pennsylvania had a wide range of ideas about dieting.

Prof Birch also found boys and girls have different attitudes to their weight and what they eat, which could lead to eating disorders. She said: "Girls have more concerns than boys about being thin and they are also more vulnerable to chronic dieting and binge eating in later life."

"Of all the girls who said they were knowledgable about dieting, virtually all of them were aware of it as their mothers were on some form of diet."

In a paper entitled Factors Influencing Food Choice Among Children, Prof Birch said parents should persist in feeding their children healthy foods which they might initially appear to dislike and stressed that youngsters should not be discouraged from eating junk food.

She said: "What children want to eat is at variance with what their parents want them to eat. However, parents should be patient and not just assume that because a child rejects something one day that they will never like it.

"Children can only learn to prefer certain foods if they are made available to them. Similarly, parents should not restrict children's access to foods they believe to be unhealthy as this has the opposite effect. We have shown that it actually increases the child's intake of restricted food."

Prof Birch, who has been researching child nutrition for 25 years, will continue to follow the progress of the 200 children in central Pennsylvania to assess how their attitudes evolve into adolescence.

She warned the problem of childhood obesity in the US could be mirrored in Britain. She said: "Childhood obesity is a huge problem in America with around 25% overweight. In Britain the comparative figure is around 15% and it appears to be catching up with US."