A discussion about best performance weight somehow became a public debate about whether or not Jessica Ennis was 'fat', raising serious issues about body image. Sports reporter Keme Nzerem reports.

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When I first the read the reports it didn't seem quite right.

"Bigwig at UK Athletics calls Jessica Ennis fat" - was the gist of the debate.

Surely no one who's involved in elite sport would be so insensitive? In any case it doesn't take a nutritionist to know that it's clearly not true.

It turns out there is a smidgin of truth behind this rather absurd discussion. But it's not what you might think.

There was a conversation last year - nothing out of the ordinary - about her ideal performance weight. And, I'm told, it involved a senior official at UK Athletics who's not known for his tact - especially when it involves a topic as thorny as a woman's body image.

Body shape and performance

Now Ennis is a tough character. You have to be, to compete at the highest level of any Olympic sport. But the heptathlon is different: seven events, testing running, jumping, and throwing.

And she has another challenge: Ennis is only 5 ft 5. She's competing against women who are often nearly half a foot taller. Thus they have longer arms. To throw as far as they can, she has to bulk up. But how much is too much? When would changes in her body shape start to undermine performance in her other events?

All this detail became lost in the world of tabloid headlines - and our obsession with what women look like - rather than what they do.

Effect on young girls

Which brings us to what made the whole farrago slightly uncomfortable.

Ennis brushed the whole episode off this morning. She told me the whole thing had been blown out of proportion and, and the last thing she wanted was for other girls to think that she worried about he weight. Because if she - a potential Olympic medallist, the face of the 2012 games, and a role model - thought she was fat, what on earth would they think about their own bodies?

And that is the point. Britain has a tremendous challenge encouraging girls to get healthy. The women's sport and fitness foundation conducted research recently that had startling conclusions - only one in 10 girls aged 14 are active enough to stay healthy, and at school-leaving age, girls are half as likely to be involved with sport as boys.

One of the biggest factors that puts them off? They are worried about body image. In practical terms ‘being sporty' at some point means parading around in a swimming costume, or getting hot and sweaty in public - activities you are unlikely to endure if you are a teenage girl, and already worried about what you look like.