Fat Nation

Is it really possible to equate the challenge posed by obesity and climate change? I suppose it could be said the government has waited much too long to deal with the consequences of either; and both problems are almost entirely man-made. On the other hand, most people already know the solution to obesity - eat less junk food, do more exercise, and use up more calories than you take in - and no matter how overweight the population of a few rich countries gets, it's hardly likely to threaten world peace or lead to environmental disaster, is it?