Another image of Ben was digitally created to show how he might look aged 21.

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The case, which was never closed, is now being reinvestigated by the Royal Military Police, with images supplied by the charity Missing People, which shows how Katrice could look now, aged 33.

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Biologically, the middle-aged human body does not look like something being left to slowly decay.

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Look, for instance, at the aged skyscrapers of Lower Manhattan.

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He never gives interviews, and the only photograph of him to appear regularly in the press shows an unremarkable middle-aged man with a quizzical look on his face and his arms folded protectively in front of him.

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Resisting the temptation to simply request "real", I opted instead for - and here's a look into my mind - a brunette, aged 25, who was well-educated and with a passing interest in stand-up comedy, film and, since we're dreaming, football.

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The authors of the study look at changes in the weight and height of a large group of Americans aged over 50 between 1992 and 2004.

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