Unlike the altruistic lion in the famous C S Lewis story, the obesity lion is roaring louder than ever before as it relentlessly expands its territory. The villagers (us) are frankly terrified. Where will it stop? What will it cost? Will it maim and destroy our children? How can we save ourselves?

There is much confusion among the villagers. We find that not only are fat people dying earlier and suffering more damage to their body parts and functions, but they are not the jolly souls we were formerly led to believe. On the contrary, they suffer depression if very obese,1,2 and, whether children or adults, experience widespread prejudice, teasing and discrimination on the basis of their size.3-7 As a group, they are less productive than their non-obese counterparts — accounting in Australia for some 4 million days away from work in 2001.8

We know there is a genetic component to obesity, but genes have always been with us and obesity on its current scale is a relatively new phenomenon. We are not sure who or what unleashed the lion. Was it too much food, too little exercise, or the changed combinations and composition of the food we eat? Was it our ever more sedentary workplaces, our passion for cars, our obsession with automatic just-about-everything, or our thoughtless urban design that spelt the death knell for incidental physical activity? Perhaps it was television and e-games. Or should we just blame parents — working mothers are always fair game — and leave it at that?

Whatever the vector, or combination of vectors, there is no doubt we are fatter than ever before, but the evidence can be puzzling and we have much to learn. Some suggest our children are more physically active than their counterparts of 20 years ago,9 and the scientific jury is still out on the relative contributions of diet and physical activity to obesity. Intensive lifestyle interventions have been shown to achieve modest but therapeutic weight loss to avert or delay progression to type 2 diabetes by 58% in high-risk individuals,10-11 but we haven’t yet figured out how best to translate this knowledge from a clinical trial setting to the whole population. And, even if we manage to do this, how do we ensure that such programs penetrate beyond the “worried well” to socially disadvantaged people living in areas where fast-food outlets are much more common than in our more affluent communities?

We know that our social and physical environment is not conducive to health and slimness, but the political, structural and ideological barriers to changing it seem insurmountable. So, driven by the innate human propensity to do “something rather than nothing” in the face of a crisis, we go to the wardrobe. Will it help if we dress the lion in different clothes? Should we call it a disease? Maybe cloak it under the mantle of a Medicare item or give it a National Health Priority hat?

Raising the status of the problem to this level has some compellingly appealing elements, such as attracting attention and funding to resolve it, but there are potential drawbacks. The resultant obesity industry may serve to perpetuate rather than resolve the problem. Pills may moderate the magnitude of the effects of obesity in individuals, but may prove an expensive population option and, even if affordable, will not address its determinants. Physical activity is a natural human function. Will reifying it into something that must be prescribed and supervised enhance or inhibit it? Will the medicalisation of obesity further cloud the issue of whose responsibility it is? Could it absolve individuals from exercising restraint — and perhaps from exercising at all? Could it localise the problem to the health sector and let the all-important transport, agriculture, public works, education and local government sectors off the hook?

Perhaps a witch hunt would help. But how far should we go? Everyone would agree that removing so-called “junk food” and sweet drinks from school canteens is a good move, but curtailing the odd sausage sizzle seems puerile in the face of the magnitude of the problem. Banning junk-food advertising to children appears all but inevitable, but, while this may have symbolic merit, there is little evidence that it makes a measurable difference. Moreover, defining junk food is highly complex and may depend on portion sizes, frequency of consumption and relative contribution to total dietary composition and energy intake as much as the nature of the food itself.

Advertising, in itself, is neither good nor bad — just a means of communicating a message — but the issues around it are equally convoluted. From a quick check of the Australian Children’s Television Standards,12 anyone can figure out that kids’ prime viewing time (technically termed “C and P [children’s and preschool] classifications”) seems to be a moveable feast, with no explicit nationally standardised real time. And a personal perusal of a few TV guides suggests that there is no mandatory requirement for identifying C and P time on the programming notices from which average parents choose what to let their kids watch. Further, in a rare insight into the real-world nutrition of very young children, Webb et al13 report that toddlers, although too young to be influenced by TV ads, are getting 27% of their caloric intake from hot chips, sweet drinks and other energy forms that one could easily be forgiven for defining as junk food. To top it all off, food manufacturers who wish to opt for responsible advertising to children may be thwarted by the lack of an agreed definition of what constitutes “responsible”.

The world has changed. We will never return to the 50s or even the 80s, when sturdy but slim Aussie kids played touch footy and cricket in expansive backyards or on generously proportioned nature strips until their irate mothers menaced them inside to bathe, eat home-cooked “meat and three veg” and do their homework. Healthy school food policies are to be applauded but do not go far enough. There is a lot of time left over outside school hours when our kids frequent shopping mall food halls and local independent fast-food outlets. If we are to truly tame the lion, we need to address the broader environment. Pills, sporting facilities, bans, community education or awareness programs will not be enough. The food manufacturing and advertising industry is an obvious and important vector for obesity and needs substantial re-engineering. We can ban their products appearing on TV, as we did with cigarette ads — which, in tandem with a raft of other strategies, worked brilliantly. But have you noticed lately how many Hollywood productions are peopled with our kids’ idols smoking incessantly? Bans, if applied at all, need to be embedded in a much more comprehensive multi-pronged approach that makes healthy food available and affordable and contemporary forms of incidental physical activity possible and appealing.

In a passionate call for a considered and logic-driven response to obesity, Yach et al14 tell us “there is a crucial need to develop a roadmap that defines appropriate interventions based on the causes of obesity at the macro- and microscopic levels from which a coherent prevention plan can be constructed”.

What might such a roadmap look like? We could start with a priority-driven research program to fill in our knowledge gaps and guide our interventions. With appropriate emphasis on prevention, health services and social policy research, this might also serve to reinvigorate the public health sector to deal more effectively with the problem. Funding acute care and community care from the same budget stream could encourage greater emphasis on primary and secondary prevention. Maybe we could increase spending on getting more people moving more often if we spent a little less on our elite athletes. And why not provide incentives and disincentives aimed at convincing the food industry to reduce the salt, fat and sugar content of manufactured and processed foods? Or take it a step further and require them to provide health-promoting workplaces for their employees. Speaking of which, why is it that we have occupational health and safety rules to prevent injuries but happily let people sit hunched over computers — barely moving — day after day after day? As part of our roadmap, employers would provide amenities and incentives for people to cycle to work rather than drive, and both employers and trade union representatives would engage in promoting health and protecting our human capital.

Consigning the lion out of the village will not be easy. If bans and Medicare items will help, let’s use them. But let’s not throw out with the bathwater the notion of producing healthy fast food and drinks or intelligent design for healthy urbanisation to ensure our towns and cities are walkable, have a health-promoting land-mix use, and encourage active forms of transport. The law could be used, not only for prescriptive legislation and consumer protection, but as a tool for redesigning the policies that shape social determinants of obesity and chronic diseases. This could underpin a cross-sectoral approach addressing food supply, trade, health taxes, incentives and much more. We have a convincing enough economic argument detailing the current and prospective cost of obesity. Let’s concentrate now on what can be saved.