When I told my children we were going to stop buying plastic packaging until further notice, they didn't bat an eyelid.

We had been looking at the front page story in The Independent last month which revealed that a "plastic soup" twice the size of the US was floating around in the Pacific Ocean. "Why don't we give it up for Lent?" suggested my eight-year-old, Joel, and my daughters agreed. (Although my youngest, Alice, confided in me later that she would find a shortage of yoghurt for 40 days quite challenging. I promised her I'd make some.) What they, and I, didn't know was what an impact a plastic ban would have on everyday life in our family of five.

I'm not talking about refusing plastic bags: I've been doing that for years. No, this pledge meant every food item I normally bought for my family would be scrutinised for plastic. Recycled and recyclable cardboard, jars, tins and glass bottles I deemed acceptable; anything made of or containing plastic or some other unrecyclable material would be rejected.

Download the new Independent Premium app Sharing the full story, not just the headlines

The 10-metre deep vortex of plastic rubbish highlighted by The Independent was first discovered by a sailor, Charles Moore, in 1997. It is now the largest mass of rubbish in the world, totalling an estimated 100 million tonnes, and kills hundreds of thousands of birds and animals every year, as well as introducing toxic waste into the food chain.

Some of the plastic in this giant swirling rubbish dump has been there for 50 years, as it does not biodegrade; toothbrushes, Lego and cigarette lighters are just some of the items that have been found in the stomachs of fish and seabirds. Plastic is believed to constitute 90 per cent of all rubbish floating in the oceans: the UN Environment Programme estimated in 2006 that every square mile of ocean contains 46,000 pieces of the stuff.

The next day – Ash Wednesday, the beginning of Lent – was my first foray into a supermarket with the intention of buying only unpackaged foods, or at least foods that were not encased in plastic. Yes, I know that for anyone with a modicum of environmental awareness, supermarkets are not the place to shop. But between them, Asda, Morrison, Tesco and Sainsbury's account for three quarters of our grocery shopping in the UK. My aim was to see how easy it would be as an "average" shopper to reduce the amount of packaging I bought, and Tesco was my first port of call.

My first realisation was that much organic fruit and veg is actually more packaged than non-organic, so it was back to standard loose potatoes, apples and oranges and the rest. After five minutes in the fruit and veg aisle, my trolley was beginning to look like a greengrocer's barrow, with things I might – in the past – have bought in a bag, rolling around in a riot of colour. It looked great to me but I noticed I was getting a few funny looks as I strolled around closely examining packets, shaking and replacing them, with apples, apricots, avocadoes, potatoes and pears parading in all their naked glory in my trolley.

One disappointment was that the paper mushroom bag had a plastic insert – another example of thoughtless over-design.

I left the dairy aisles almost empty-handed: All the cheeses were in plastic wrapping – some unnecessarily on plastic trays inside plastic wraps. I settled for an organic cheddar in a sort of greaseproof paper printed with trees, figuring (hoping) that it must be bio-degradable and making a note to self to check when I got home. Out went margarine or spreadable butter in favour of a paper wrapped block of butter – easy. No yoghurts today, though.

Tins of tomatoes and beans were OK but jars turned out to be a different matter. Yes, the glass can be recycled, but all those lids! Some were tin, which I could recycle with the cans, but an amazing number of lids are plastic. To add insult, many jars also have a "tamperproof" plastic seal around the lid. Lids on plastic bottles and Tetrapaks were all plastic, so there could be no squash or juice for the kids in that form – or milk. How would I get round that one?

Porridge oats in a 75 per cent recycled cardboard box were the only cereal item without a plastic inner bag, so in they went. Porridge is a staple breakfast in my house anyway, but I wondered how soon the children would get bored of it without the odd morning of cornflakes or Rice Krispies.

Eggs were the answer. My usual seeded brown bread in a plastic bag was replaced by a French stick in a paper bag, as well as some flour so we could bake our own.

But when I got to the frozen section I realised things were getting tricky. No frozen peas or sweetcorn – my handy vegetables of choice when the kids are hungry and I have to whip up a meal fast. I vowed to buy fresh peas and corn from the local grocer, where I could top up my meagre haul with cucumbers, lettuce and other salad items that were not tightly bandaged in plastic.

At the checkout, the sulky teenager didn't bother to hide his annoyance as new potatoes and satsumas rolled off the weighing area.

A couple of days later, I found the same problems in Asda and Morrisons, leaving with a small bag of non-packaged goods to fill some gaps in my food stash. By this time, I confess, I had given up on finding milk without a plastic lid and bought some (although my research had revealed that some milk companies are planning to drop the handle on pint and two pint plastic bottles in favour of a more lightweight design).

Just as, sometimes, you split up with a partner and then find that every song you hear on the radio is a love song, so I found that now I was trying to avoid plastic it was everywhere I looked. So I changed my shopping habits radically. Carrying my organic cotton bag around with me I became a much more random, opportunist shopper.

In the Co-op next to my children's school, I nipped in when I spotted an unwrapped cucumber. I bought cheese wrapped in paper at the deli down the road and took the kids to the proper greengrocers, who were happy to tip everything into my bag. I ordered a local organic vegetable and fruit box with earth still caked to its cargo and cooked vegetables I wouldn't normally buy such as turnips and celeriac.

By the end of week one I had already fallen off the plastic wagon: an unforeseen shortage meant a visit to our corner shop for recycled toilet rolls – wrapped in plastic that was "recyclable where facilities exist".

I gave the kids money for ice creams that lovely sunny weekend as we lounged on the beach and they came back with ice lollies wrapped in plastic– didn't they used to be wrapped in paper? One day, I also bought a replacement toothbrush for my husband. Maybe I could have found an alternative, but I didn't have masses of time left over that day.

By the start of week two, the kids, to their credit, hadn't complained about the relentless porridge breakfast diet. But the cats slunk off in disgust when I produced boxed cat crunchies instead of their usual veterinary approved stuff in a big bag.

My larder of existing food was looking depleted, but I was determined to improve on the previous week. My children's school (Brighton Steiner School) has a policy of no pre-packaged food in lunchboxes, so there was no big change in their lunches. The school even has a dry wholefood goods shop. I ordered in bulk to save packaging.

I also wrote something in the school's weekly newsletter mentioning the "plastic soup" and asking for tips. A few parents got in touch: one told me she and her partner had not shopped in a supermarket (bar the more ethically minded Co-op) for three years. A friend told me that when she stopped buying fruit and veg in plastic, she was able to put out just one carrier bag of rubbish per week – not bad for a family of four – and that she was getting rid of things such as bubblewrap and jiffy bags through the community swapping website, Freecycle.

Ten days into my crusade, I felt I was making a (small) difference. My children were enjoying cooking with me more, making different types of bread and experimental cakes. My husband even offered to make pasta ( but the pasta cutter had rusted.)

I asked several food companies whether I could recycle their packaging and was mostly fobbed off with the reply that yes it was recyclable "where facilities exist". They don't. Not where I live, anyway. I phoned the local council and the "household waste depot" and was told that only plastic bottles could be taken there for recycling. What is so frustrating is there are so many types of plastic packaging which seemingly can't be easily recycled. Only the simplest, marked "PET 1" on most plastic bottles, is taken by kerbside recyclers.

Why has plastic become so widespread as a packaging material? All food manufacturers I contacted gave the same reason: plastic has proved the most successful material for wrapping food because it keeps it fresh and is durable enough to prevent leaks and spills during transportation. Longer distances between food producers and consumers have led to a greater demand for packaging, as has the increase in working families, the spread of microwaves and freezers.

Insufficient packaging is a major contributor to food waste. A shocking statistic from the Industry Council for Packaging and the Environment is that more than six million tonnes of food from UK households alone goes to waste each year. The British Plastics Federation, making the case for plastic, says that in Britain, where use of plastic is widespread, food waste accounts for just 3 per cent of food produced – compared with 40 per cent in the developing world.

Meanwhile, plastic is clearly ingrained in British consumers' buying habits and is unlikely to disappear overnight – or not until the oil runs out, anyway. But alternatives do exist: London Bio Packaging is one of a handful of new companies that manufacture packaging made from plant materials which breaks down in compost or landfill within six to eight weeks. Charlie Vaughan-Lee, a director, told me that, having started up two years ago, the company now has 650 companies using its biodegradable packaging, with many London offices using the compostable cornstarch coffee cups.

Mr Vaughan-Lee named M&S as one company that is proactively working to reduce packaging and, on a visit to Sainsbury's, I discovered that most of its So Organic range of fruit and vegetables uses compostable packaging.

There are also a number of organisations – among them Wrap and Waste Watch – that encourage consumer brands to embrace recycled and biodegradable materials, while the plastics waste management industry has set itself the task of moving towards more environmentally sound practices with its organisation Recoup.

As for us, by week four of our experiment we have got used to living without some things, and I am putting aside more time to make staple items such as bread and yoghurt from scratch. On day 32, however, two of my kids tell me that there hasn't been enough in their lunch boxes all that week. I feel terrible and, looking at my vastly depleted larder, I realise there just aren't enough of the everyday things I have taken for granted for so long. A new Lidl has opened near the school and, that day, I give myself permission to buy some of the children's favourite things.

It feels like Christmas as I put frozen peas and a big block of emmental into my basket, then choose some breakfast cereal they haven't had for a month. I also treat myself to some feta.

As I pack away my haul with at least five or six plastic packaged items, I feel that I have in some way failed. But I also know that my buying habits are unlikely to change back to the way they were before. I have already proved that I can't live 100 per cent without plastic. Maybe 98 per cent will do for now.

Plastic: the facts

*Packaging represents the largest single sector of plastics use in the UK, accounting for 35 per cent of UK plastics consumption. Plastic is the material of choice in nearly half of all packaged goods.

* Packaging accounts for 60 per cent of household waste, and 11 per cent of household waste is plastic, 40 per cent of which is plastic bottles.

* On average, every household uses 500 plastic bottles each year, of which just 130 are recycled. The UK disposes of an estimated 13 billion plastic bottles per year.

* According to a 2001 Environment Agency report, 80 per cent of post-consumer plastic waste is sent to landfill, 8 per cent is incinerated and only 7 per cent is recycled.

* More than 80 per cent of plastic is used once and then thrown into landfill sites. More than 60 per cent of litter on beaches is plastic.

* We produce and use 20 times more plastic today than we did 50 years ago

* Plastics consumption is growing about 4 per cent every year in western Europe

* Plastic food packaging uses about 4 per cent of all crude oil.

* Reprocessor demand for plastics outstrips supply three times over

Sources: FOE, Waste Online, Recoup, BPF