Catch the Fat!

A UK newspaper has headlined the story that obesity may be contagious (http://express.lineone.net/posts/view/53983/Getting-fat-is-catching), based largely on an American claim that has been bubbling around for some time that adenovirus infections cause adipose cells to multiply. It has also (naturally) been observed that obesity 'runs in families' but that is, of course, more likely to be a consequence of people adopting a common life-style and diet rather than sharing the same gene(s). There may well be modest genetic and virus-associated aspects of obesity but I personally feel that it is unhelpful to try to 'sell' fat people the idea that they have (no fault of their own) a medical condition (although we know obesity per se is associated with a wide range of medical risks). For the vast majority of people, calorie intake minus calorie utilisation is the major equation involved in gaining weight (in spite of steroids changing muscle mass, maturation generally increasing body size, degree of body hydration producing transient changes etc). Diet and exercise seem to be is answers for most folk. A detailed BBC Horizon programme (http://news.bbc.co.uk/1/hi/magazine/7838668.stm) explores many of these issues concluding that some obese and skinny people have body mechanisms (e.g. sensations of constant hunger or increased metabolism) that tend to return them to their 'natural' weight when they respectively lose or gain mass as a consequence of taking in restricted or excess calories.