As a dyed-in-the-wool libertarian, she ticks off our highly interventionist government week-in, week-out for meddling in our lives, but when it comes to the obesity epidemic, she is all for traffic light labelling, government health warnings ("cake can kill"), junk food taxes - the lot. Given the likely cost to society of the consequences of unchecked obesity, you can understand her change of tune. Something must indeed be done.
The question, of course, if we are genuinely interested in reversing the growth of obesity, rather than enjoying the satisfying feeling of taking decisive action, however directionless, is what to do. This week, five large food companies announced a joint campaign to promote a different form of food labelling from the traffic-light system favoured by the Food Standards Agency and the prime minister - GDA, "guideline daily allowance" of sugar, salt and fat. Tesco has lent its support to this route.
To my mind, a system that clearly tells people how much sugar/salt/fat is in the food they buy is preferable to one that tells them something is either good (green), bad (red) or neutral (amber). I prefer information to opinion on my food labels and the traffic light system looks judgmental to me. At what point does a product trip from being amber to red, for example? And who decides?
Not everyone agrees. Sainsbury, Asda, Waitrose and the Co-op back the traffic-light method and food campaigners think it is simpler for consumers to understand. What's more, there is evidence it has an effect. Sales of Sainsbury's own-label chicken madras fell by 40 per cent once it was labelled red. But is this a consequence we really intend? Are "red" products so inherently dangerous we want them killed off?
Obesity is a simple problem (too many calories in, not enough out) needing a complex solution. Shows such as Jamie's School Dinners and You Are What You Eat are more likely, in my view, to contribute to changing people's attitudes to their diet - and, of course, it is diet that counts, not individual foods.
Clear, sensible information on food packaging is a must, but the Government should make, or encourage, at least as much noise about the need for regular exercise, the consequences for health of poor diet, and the appalling costs to society of spiralling NHS costs. It has in effect to sponsor a multimedia communications campaign on the whole issue - not just bits of it.