Obesity is 'collateral damage in the battle for modernity'. It's an unintended but unavoidable consequence of economic progress.Obesity is not a disease but a signal. It's the canary in the coalmine, which should alert us to bigger structural problems in society.There are a number of areas where humans have achieved a peak of success, a sweet spot, but now that very success is turning on us and threatening to unravel centuries of achievement. On the one hand, economic growth has over centuries led to a steadily improving standard of living, better levels of health and ever increasing life spans.On the other hand, this very affluence is the reason that both our bodies and the planet have gone into a downward spiral, manifested by an ever growing epidemic of obesity in humans, and in a world clogged by greenhouse gasses and waste.Our bodies can no longer cope with the excess of over consumption to which we are encouraged at every turn, and the planet is labouring under the effect of industrialisation and greenhouse gas emissions which are surely exacerbating and possibly causing a level of climate change which is ultimately unsustainable.A fundamental change in thinking is needed both for how we treat our bodies and for our approach to the planet.Each is the only one we have.