Scientific research article for Diabetes UK’s healthcare professional magazine
Fat’s what it’s all about
For decades we’ve regarded body fat as something to be purged by practically any means possible. But recent years have transformed our understanding of this much-maligned substance. Brian Burns surveys the implications this changed understanding has for diabetes care
Though it is spread throughout the body in a number of specialised depots – under the skin (subcutaneous fat), packed around internal organs and encasing the lymph nodes – it is now clear that body fat is not simply a warehouse for excess energy. It is, instead, a complex organ – comparable in its functions to the liver – that actively regulates appetite and energy balance by means of hormonal and neuronal signals routed via the central nervous system, with the hypothalamus playing a central role.
A greater appreciation of the complex processes of chemical signalling within our bodies is the keynote of fat’s recent rehabilitation. Those signals that prompt us to eat more also tend, generally, to make us conserve energy, while those that make us eat less also spur us to burn off more energy. Some signals govern short-term actions, eg the end of a meal; others govern longterm actions, eg conserving energy stores.
This new understanding has triggered a boom in research into the hormones, proteins and genetic factors involved in the body’s sophisticated communications network, with a view to developing new and more effective therapies to treat obesity and diabetes, as well as methods of identifying those most at risk of developing these conditions. (While it is beyond the scope of this article to convey fully the complexities or range of this research, a few of the most promising contenders are briefly summarised in ‘The fat controllers ’, see across).
However, knowing that fat – ‘the complex organ’ – is a good thing per se doesn’t mean that being fat is also a good thing. Stretching a comparison, a healthy liver is a good thing; one enlarged through abuse definitely isn’t. Ditto body fat. Our growing appreciation of what body fat is does not make unprecedented levels of obesity worldwide any less problematic. In part, obesity is on the increase precisely because the very systems we depend on to regulate the delicate balance between energy intake and expenditure are at odds with our current environment.