The research comes from Pennington Biomedical Research Centre in Louisiana, where a team lead by Professor Nikhil Dhurandhar found that chickens and mice infected with an adenovirus gained more weight than their uninfected brethern, even when given the same amount of food.
Adenoviruses are commonly known as a cause of respiratory infections. The particular virus in question is known as human adenovirus 36 or AD-36. In a previous study published in 2005, Dhurandhar found that whilst 11% of non-obese adults carry the virus, the figure shoots up to 30% in the obese population.
Does this mean that the easily-spread virus is responsibly for obesity? Well, whilst the team’s research showed that cells infected with AD-36 absorbed fat more easily, it can’t be the sole cause – after all, only 30% of obese adults are infected.
The Telegraph article soon backs down from its inflammatory headline (no doubt added by some hapless sub-editor), with quotes from numerous people questioning the claim. Dr Ian Campbell, a GP and medical director of the charity Weight Concern spells it out:
“A virus will never be the reason for why we have an obesity epidemic.
“There are far too many other factors, starting with our calorie intake exceeding our expenditure, and that’s because we live such sedentary lives.
“Our dietary habits have changed beyond belief and I don’t believe that’s the effect of a viral infection – it is the fault of the commercial expansion of companies making unhealthy foods.”
So, whilst AD-36 could be a contributing factor, the most important aspect of weight gain is simple. To butcher Dickens:
“Daily calorie expenditure two thousand, daily calorie intake nineteen hundred, result happiness. Daily calorie expenditure two thousand, daily calorie intake twenty-one hundred, result misery”
In other words, it’s the same old boring advice; eat less, exercise more.
As an aside, it’s interesting that David over at Sciencebase notes that Dhurandhar has been chasing the “obesity bug” for over a decade, seemingly trying to replicate the medical paradigm shift that occurred after the realisation that peptic ulcers were caused by bacteria, and not stress as previously thought. Scientists are people too, and like everyone else they have their own personal agendas. One to look out for, I think.