Live fast, die young, is a philosophy of life that applies not only to tragic film stars such as James Dean and Marilyn Monroe; it is also true of some groups of people. Pygmies have a notoriously short lifespan - among the six groups that have been studied, average life expectancy ranges from 16 to 24.

And that, scientists speculate, means that they have to live fast. Until their teenage years, pygmy children grow as quickly as Americans. Then, at about 12, they suddenly stop getting taller and their bodies' efforts are redirected to reaching sexual maturity.

This, according to research in the Proceedings of the National Academy of Sciences, explains why pygmies are short and reproduce early (fertility peaks at about 15). They have to adopt this strategy in order to produce and raise the next generation before they die. In contrast, American teens stop growing at around 20, which coincides with their fertility peak, and die, on average, in their seventies.

The paper, by Dr Andrea Migliano and colleagues at Cambridge University, weakens other theories seeking to explain the diminished stature of the pygmies: food shortages (small body, smaller meals); ease of navigation (easier to get around in a dense habitat); or body temperature regulation (a smaller body cools more efficiently).

A worrying development on the MRSA front: researchers in San Francisco and Boston have reported a virulent, multidrug-resistant strain circulating among gay men. Sexually active gays are 13 times more likely than the standard population to contract the USA300 strain, suggesting it might be sexually transmitted, a paper in the Annals of Internal Medicine reveals.

Dr Binh Diep, of San Francisco General Hospital Medical Centre, says: “These multi-drug resistant infections often affect gay men at body sites in which skin-to-skin contact occurs during sexual activities. But because the bacteria can be spread by more casual contact, we are also very concerned about a potential spread into the general population.”

I'm not really a low-fat kinda girl. It's either double cream or quits. The reason I shun low-fat foods is that they never taste as nice as full-fat versions.

Now food researchers at Birmingham University think that a fungal protein might make low-fat foods taste more convincing. The protein, called hydrophobin, can be used to make air-filled bubbles which, in terms of texture, are similar to the oil-filled bubbles in fatty foods. And since it's the texture that seduces us, a food stuffed with bubbles blown from hydrophobin should taste similar to the high-fat version. Professor Ian Norton says that about half the fat content of mayonnaise could be substituted with hydrophobin and we would probably not be able to tell the difference. How about working that magic with tiramisu?

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