Slim Your Waistline - Not Your Wallet

Not all food prices are rising. In fact, some of the healthiest food is now cheaper than ever.

We all know that food prices are going through the roof. The latest official inflation figures reported mournfully that the cost of food is up nearly 10% on a year ago, the fastest rise since records began.

But what's less widely known is that not all food price rises are equal. In fact, some kinds of food haven't got pricier at all - or are even getting cheaper.

Even better, this includes some of the healthiest, greenest, leafiest things you can put in your shopping basket.

Credit munch

Much of the rise in food prices is down to one thing: Cars.

The American government has decreed that more of the maize harvest should be used to make biofuels, pushing up cereal prices around the world.

As a consequence, bread, pasta and rice have all shot up. The latest inflation figures show that the price of bread and cereals was up 11.9% on the year.

And there have been knock-on effects all along the food chain - particularly on animals that eat grain. Red meat and chicken have also rocketed. Milk, cheese and eggs were up nearly 20%.

Fishy business

Less widely known is the fact that the price of fish has failed to keep pace with the rise in the price of meat and dairy.

The official inflation figures from the Consumer Price Index (CPI) show that fish prices went up just 1.5% over the past year. Compare this to the cost of meat - particularly beef - which is rising at a rate of 11.2% a year and you can see that fish is now relatively cheap.

Part of the reason for this is that fish don't eat grain. And part of the reason is that countries such as China and India aren't adding fish to their diet as much as meat.

But never mind the reason, the fact is that fish, by comparison, is now exceedingly good value, which means it is back in fashion here at The Fool.

On Waitrose's fish counter, a whole English trout can still be had for £1.83, for example. Roast it with herbs, close your eyes, and it's almost as if the credit crunch never happened.

Best value of all - and healthiest of all - is oily fish. In Waitrose, Cornish herrings are £4.99 per kilo, mackerel is £5.99, and shiny silver sardines (great on the barbecue, with olive oil and lemon) are just £3.99 per kilo.

For four quid, that's enough fish to give four people one of the healthiest dinners you can buy.

Even better, many British oily fish are at their tastiest in the summer catch.

Eat your greens

What makes a low-calorie accompaniment to fish? Perhaps some grilled red peppers, or a fresh tomato salad.

So it's fortunate that vegetables have also stayed relatively good value.

While some types of veg have undoubtedly gone up in price, for the savvy shopper, there are definitely bargains to be had.

The official data shows that vegetables were up 7.4% over the year to July - far lower than meat or dairy products. That includes potatoes, which have gone up in price. However, it's been a good harvest this year for many salad vegetables, particularly those grown in Britain.

The brilliant price comparison website MySupermarket has been tracking a basket of food essentials over the past year. It found that in July, packs of six tomatoes were exactly the same price this year as last in Tesco, Waitrose and Asda.

Bags of mixed peppers were only 7% more expensive in all three supermarkets.

By contrast, MySupermarket found that packs of beef mince were up around 60%, and blocks of Cheddar around 35%.

A juicy bargain

Orange juice is another cheap and virtuous treat. Back in July 2007, a litre of orange juice would have set you back 88p. In July 2008, the price hasn't moved by a single penny.

It's a similar story when it comes to apples. Bags of Golden Delicious apples were up just 1.4%.

Of course, fruit and vegetables can be expensive. The trick is to shop around and stick to discounted items, which are the ones in season. If you buy from your local market, don't be afraid to ask what is the bargain of the day.

My friendly local greengrocer tells me that courgettes, lettuce, spring onions, apples and plums are all great value at the moment.

Another tip - for those counting either calories or pennies - is that supermarket frozen and tinned vegetables can be just as healthy as fresh, and often prove better value. Michel Roux recently recommended using bags of frozen fruit to make berry coulis, for example.

If it's good enough for a Michelin-starred chef, it's good enough for me.

Do it yourself

Fish and vegetables are all very well, you might say, but what about bread?

There's no getting around the fact that the daily loaf has got more expensive, but here are two tips that might help to save you both money and calories.

Make your own! A 1.5kg bag of flour in Waitrose is 79p. Add yeast at a few pence and the cost of cooking - and that's still three fresh, unprocessed loaves for less than 50p each.

Opt for an alternative. Rye bread is often relatively cheap. That's because the price of rye hasn't moved as fast as wheat. The fact that it's healthy is a bonus.

Cut and count

Of course, the simplest calorie and cost cutting trick of all is to eat less, as recommended by my Foolish colleague Malcolm Wheatley.

If only it were that easy. But at least you can avoid being tricked into buying food you don't eat - my Foolish colleague Serena Cowdy has a few hints on spotting the supermarket scams that manipulate you in this way.

My own top tip is that MySupermarket lets you compare calories on different products as you shop, as well as the price.

Nowadays, it seems, there really is no excuse for not watching your waistline -- and your wallet!

More: Fight Back Against Rising Food Prices | Listen to our MoneyTalk podcast on food prices