Another day, another story about the shocking ingredients found in processed foods. The story is worth reporting, and Alex Renton is right to highlight it in his blog post here. Kellogg's Frosties, 37% sugar by weight? We need to know this kind of stuff.

But should we be surprised when bloated figures hit the headlines? I agree with the tone of the comments; the more appropriate response is: 'Duh!'. When you rely on processed foods for pleasure and nutriment, you are effectively throwing yourself on the mercy of manufacturers. These organisations aren't monsters, they're simply businesses. They are interested in healthy profits, and they know they can make them by selling lots of unhealthy sugar, salt, and saturated fat.

You're probably too clued-up to be buying the worst of these nutritional nightmares. But I'll bet you eat more processed food than you realise. And do you know what's in it? Processed food is, by nature, a disempowering source of calories.

If you want to seize back that power, run an audit of your processed-food consumption. I did this a few years ago in a domestic experiment which banished all processed foods from the house for a month. It opened my eyes to how easily you can come to lean on the things.

First of all, what is processed food? The US Food and Drug Administration defines it as:

"any food other than a raw agricultural commodity and includes any raw agricultural commodity that has been subject to processing, such as canning, cooking, freezing, dehydration or milling"

This broad definition includes pasta, oil, tinned tomatoes and many other staples.

For my experiment I cut myself some slack and defined "processed" as any product containing more than two ingredients excluding water. I called it the Three's A Crowd rule. This didn't rule out staples such as rice and pasta and oil, but it did forbid some sorely missed standbys. Bottled sauces (including ketchup and soy sauce), breakfast cereals, many breads, and store-bought relishes were out. So were simple items such as the sausages sold by our local butcher, and even tinned tomatoes (tomatoes, salt and preservatives).

Was it painful? Only in part. Some in the house adapted more easily than others: children who adore Heinz ketchup with sausages and Special K for breakfast were out of luck. For me, the dietary part was relatively painless.

The pain came mainly in the form of extra time needed for preparing meals. Without my precious bottle-bank of exotic sauces I needed to prepare things from scratch to add oomph and sparkle to simply cooked poultry, fish and meat. All stock had to be homemade. All tomato sauces, ditto.

But we lived to tell the tale, and I realised that you can cut processed foods right down to a minimum if you have the determination – and a bit of extra time in your cooking day.

If this is an experiment you'd be interested in undertaking, I'd like to suggest two things. First, conduct an audit. Decide what you think you really can't live without, and what you've merely come to rely on out of sloth or habit. Share your results with the rest of us and compare notes with fellow Word of Mouthers. Maybe we can compile a list of processed foods that no one really needs. Frosties might be first on the list. What else would you nominate?

Second, try doing what I did. Banish the Three's A Crowd crowd from your diet for a week (or even a month) and see what happens. I'll bet no one will die as result, and you may find that your cooking is transformed in the direction of freshness, quality and individuality with a concomitant transformation of your shopping habits in the direction of lower cost. We'll post again in a week's time so you can tell everyone how it went.

So what should be on our list of foodstuffs to try to do without, and who's up for the experiment of living without them for a week? We're all listening. No one is going to say 'Duh!' when you spill the home-made beans.