POLITICIANS keen to talk Britain up as a more egalitarian society are fond of saying we are all middle class now.

In reality, we are all bin men now, sorting out our weekly rubbish like assembly line workers. This tin needs to be washed and goes in that bin; throw those potato peelings on the compost; and isn't the bottles box heavy these days?

Given the amount of time we spend on the task one would have thought we would notice all those fivers and tenners languishing among the dog food tins and pizza boxes. According to the Institution of Mechanical Engineers (IME), up to 50% of food bought is thrown away. That's £480 straight in the bin.

In the developing world, waste happens because farmers have limited means to harvest, store and transport food. In the rich, developed world, there are no such excuses. It is in our households that so much food is wasted. That is if it gets to us in the first place. Due to supermarkets imposing strict standards on size, shape and colour, anything out of the ordinary is rejected. The IME reckons 30% of the UK's vegetable crop is turned down for such reasons. How do we like them apples? Not much is the answer.

This affair between Britain and the bin costs £24,000 over a lifetime. Imagine all those holidays not taken, all those times you could have had the heating on after all, and it is hard not to feel queasy.

It is a scandal which exposes Western attitudes to food, the dominance of supermarkets and our general reluctance to value the simple and wholesome over the expensive and manufactured.

Despite being so basic to health and wellbeing, food is a complex business. It is one area of life where the personal really is political, and the debate can become very personal indeed. No story about obesity, for example, is complete without someone wagging a finger at the poor and lamenting that this burger-chomping, microwave meal-making lot should stop being a drain on the NHS.

The cheapness of fresh fruit and veg is usually cited to show there is no excuse for not eating well. Cheapness is relative, however, if there is not enough on your power card to have the oven on for the time it takes to cook a casserole. Or if you do not have an oven in the first place. And imagine washing up all those pots and pans by hand rather than hiding them in the dishwasher.

It is one thing having the means to buy fresh food, another to have the skills to cook it. At the end of December, just as many families were rushing out to buy even more grub they did not need, there was a depressing survey about Britain's cooking skills, or lack of them. According to research by a cookbook publisher (vested interest duly noted), putting a frozen pizza or chips in the oven was considered "cooking" by millions of parents. In the 1980s, 40% of people would cook – that's peel, chop, boil or bake – a meal every night. Today, it is 20%.

There was much mirth years ago when Delia Smith told her readers how to boil an egg. In 2013 cook books would be wise to include a description of a kitchen, a pan, plus instructions on how to fill it with water from the tap (not bottled). Though food porn continues to fill the television schedules and the bestseller charts, and the kitchen is meant to be the new centre of the home, only a fraction of the population seems able, or willing, to cook.

Putting more cooking into the curriculum is one answer, but learning to cook is something that was once done almost by osmosis, as children watched their mothers. By children, of course, we mean girls. Here we come to the spicy part of the great food debate. Contained within many lectures about healthy eating is the unspoken wish that women, having spent so long trying to get out of the kitchen, should get back in there, pronto. These are the same women who are working longer hours at jobs that are harder to come by and increasingly difficult to keep.

In the kind of world in which kitchen ads are set, happy shiny families would sit down to a fresh, home-cooked meal every night and twice on Sundays. In reality, budgets are under pressure, parents are frazzled and the closest many children get to real food is pictures on their iPad. Even so, individuals can play their part in reducing food waste by not buying so much and planning ahead. While it comes down to time again, change is possible.

Given that most food shopping is done in supermarkets, the rest is down to our friendly local behemoths. As someone who once had to make do with one tiny local shop that charged whatever prices it could get away with, I am reluctant to join the queue to bash supermarkets. I like supermarkets. I like food being piled high and sold relatively cheaply. The policy of successive governments to keep food cheap, so cheap it now accounts for just 11% of the household budget, has had its down sides, the effects on animal welfare being the greatest and grisliest. But access to safe, decent food at a reasonable cost is a basic right that supermarkets help to deliver – for a price of course.

Yet supermarkets are still more sinning than sinned against. Buy one get one free offers encourage waste. Sell-by dates are treated as gospel by some consumers, and jokes by others. There has to be a clearer way of explaining things so the customer is not left to take a chance. Food poisoning is a high price to pay for trying to save money. As for misshapen vegetables, is it supermarket managers or consumers who are insisting on perfection? If the price is right, few will care whether their carrot or potato could once have been an item on That's Life.

While the money squandered on food waste is shameful, the human cost is the real disgrace. As the IME points out, there will be nine billion mouths to feed on this planet come 2075, three billion more than today. From being a Western bad habit, wasting food will become a matter of life and death. Something to chew over when next the bin beckons.