McCain's inability to differentiate himself from the legacy of George W. Bush has been a major thorn in his campaign late in the piece. But sifting through the morass of statements and policies that have been issued by either camp, it's hard to find much to offer the US people and the interdependent world on a future food policy.

Yes there is plenty of rhetoric on foreign affairs and trade, energy, climate, health care, labour markets and industry protection, but virtually nothing on the US approach to food, which has a strong linkage across all those major policy areas.

A major thought-leader in food has felt the need to rectify this gap, and placed an open letter to the successful candidate in The New York Times three weeks ago in the hope of raising the profile of the issue.

Whether you agree with author Michael Pollan's arguments or not, it is the basis of a fairly reasonable debate that the US farmer subsidy should be having very soon.

There's no real change in sight in policy platforms of McCain and Obama ingredients to US agriculture, energy and climate change that propel billions into sustaining low-cost commodity food production systems.

One of Pollan's main concerns is that national policies subsidise the least healthful calories that US citizens eat.

He notes the "building blocks" of fast food are soy and corn, used to make soy oil, protein and starch in dairy and beef cattle, chicken feed, and high-fructose corn syrup used in sodas and sweets.

There you have the basis of the low-cost American diet which he says is feeding the obesity rates of the large low-income segment of the US population.

The argument extends - unless reform of the entire food system is a top priority, the US will not be able to make significant progress on the health care crisis, energy independence or climate change.

Too much is locked into keeping things cheap for the poor masses.

The ripple effect into other countries is also relevant, and a major tenet of what the developing world has argued in the WTO.

The result of the US's oil-dependent, unsustainable, non-local food supply system is that the poorest on our planet are starving because of freakish shortages.

Pollan argues further that politicians are futile in offering to reform and expand the health care system, without confronting the public-health catastrophe that is the modern American diet.