Water, we save. Energy, we conserve. But food, it seems, we can waste, junk and bin and no-one cares. Except one crusader, whose 20-year project has proven what should have been obvious in the first place: our attitude to food is costing us a fortune.
Deep in Arizona, this lone, but dedicated university researcher has spent a lifetime organising his students to count food in, count food out and measure the waste at every stage along the food chain. His findings have been salutary. Of the food we begin with, barely half is ever eaten.
Nor are the biggest sinners at the top of the food chain. In agriculture, where fields may be ploughed over with food not worth selling after subsidies, and in food processing, food waste costs $20bn a year.
But retailing then discards food worth a further $30bn to $40bn, with convenience stores alone junking 26 per cent of the food that enters their hands, only to be topped by consumers, who bin a further $43bn worth.
These figures, compiled by Dr Timothy Jones, are for the US, where many might argue food waste is likely to be at its most extreme.
But everywhere else, and indeed everywhere except for Arizona, no-one is even counting. On the subject of food waste there is a ghastly silence.
Even the world's leading food bodies, such as the Food and Agriculture Organisation, barely mention the issue, except for some estimates of wastage rates in agriculture, a quarter of a century old, that still rest in the archives.
How has an issue of such global import slipped through the information web? And at what cost?
In the absence of information, and thus discussion on how we treat food in the nurturing of our planet, the waste has gone unnoticed and therefore unchecked.
The result is not only an avoidable economic burden, but also damage to the environment, depletion of world resources, and a contribution to global warming through soil exhaustion, unnecessary fertilizer and water use and excessive landfill use.
It could be so different.
At mid-summer in the northern hemisphere, with water closely monitored to ensure we never dry up, we all see efforts to stop water waste: indeed, the counting, monitoring and campaigning about water continues world-wide, in all seasons.
Last month, Dublin authorities launched a campaign to cut daily water wastage by 10 litres per head. In France, hosepipe bans now colour most of the polygon's map. In Guyana, the government has recruited, trained and deployed water inspectors to cut the waste. And in southern Australia, the government is now considering implementing legislation to make water waste an offence.
Investment in infrastructure, to stop leaks and maximise recycling, has also made water go further, as have raised water charges. In Singapore, the water tariff has been increased to discourage waste, as it has been in many nations around the world.
And where campaigns and rules can't stop the running tap, and higher costs don't stem it, social pressure has been brought to bear. In Australia, a "Smart Approved WaterMark" now identifies water-saving products and organisations.
But public pressure is no tool where people don't know a problem exists.
If we are ever to eat more than half the food that we make, it is time to collect the information on food waste, report it, publicise it, campaign, legislate and honour the food-efficient.
Where food IS plentiful, there will always be a tendency to waste. But if we can establish the wise use of food as morally sound, and its wastage as the opposite, we all and our planet will end up the richer.
Not just the US, where food waste now costs $100bn a year.