The healthy-eating message is falling on deaf ears. So one group of scientists has a new goal - to create junk foods that are good for us

It is the new holy grail in the crusade against Britain's bulging waistlines - a low-calorie, vitamin-enriched hot dog that can prevent cancer and reduce cholesterol, and yet tastes exactly like the real thing.

It is the new holy grail in the crusade against Britain's bulging waistlines - a low-calorie, vitamin-enriched hot dog that can prevent cancer and reduce cholesterol, and yet tastes exactly like the real thing.

For decades, health experts have pushed the same messages to combat obesity: eat five portions of fruit and vegetables a day, cut out cakes and take more exercise. Now, they are admitting that these tactics have failed dismally. Obesity rates have trebled in the last 20 years and we are facing the prospect of the next generation of children dying before their parents because of weight-related problems.

Instead, scientists and nutritionists are adopting an "if you can't beat them, join them" approach to the problem. Rather than demonising unhealthy and processed products, they are looking at ways of turning "bad" foods into good, while making the good even better.

The latest techniques involve changing the way in which foods are digested to increase feelings of fullness and suppress appetite, as well as manipulating the composition of fats and oils to reduce their unhealthy effects.

Dr Gary Frost, head of the nutrition and dietetics department at Hammersmith Hospital in London, says: "We are staring down the barrel of a gun at the present time, in terms of the obesity problem. Banging on about unrealistic goals is not really an option, because 10 or 15 years of a sensible, healthy eating policy has made very, very little difference. Unless we come up with clever ways to manipulate what we like to eat at the present time, we will see rates of obesity continuing to climb."

He continues: "We have to accept that tastes and attitudes have radically changed in this country. Of course, education and exercise and healthy messages are still part of the solution, but we have to be realistic and admit that we cannot stop people eating burgers and cakes and fatty goods. People do not cook as much as they used to, and we now need to look at how we can make processed foods more healthy. The ultimate goal may be to have a burger that has the same texture, taste and appearance as before, but is maybe enriched with vitamins and has a low-fat content."

Lower fat and reduced-calorie foods have been around for years, of course, but the key problem has been that they simply do not taste as nice, or give the same feelings of satiety. Scientists at the Institute of Food Research are now working on how to make "unhealthy" foods less fatty while retaining taste and texture.

Richard Faulks of the IFR says: "Our knowledge of the ways in which different foods are digested and processed by the body has grown hugely in recent years. Before, we had very little understanding of how appetite works. Now, we have a computer model where we can input any kind of food and get an exact reading of how it is digested, how satiety works and how the energy is released. It is this work that will allow us to manipulate foods to make them potentially more healthy."

Researchers at the institute are currently working on ways to keep fat on the surface of the food, to retain taste and texture, but replace the interior of the fat emulsion with water. Other techniques include manipulating the digestive qualities of food to fill people up faster and reduce the amount they want to eat.

"The biggest problem is to get baked goods like cakes and bread to taste the same while reducing the fat content," says Faulks. "We are getting close to that now. In the next few years we should be able to get products on to the market that to all appearances will look like treats, but will actually be fat free."

But will food manufacturers and junk food purveyors such as McDonald's really want to alter their products to make people feel fuller quicker, thus reducing the amount they buy? Faulks says it is in their interests to do just that. "At the present time, we have increasing rates of chronic morbidity and premature death due to obesity," he points out. "The food industry is losing out because these people are being taken out of the market. If you have a healthier population who are still buying food but not falling ill, surely that is good for profits - and the nation."

Indeed, the industry is streets ahead when it comes to manipulating and adding to foods to make them healthier. Walk down any supermarket aisle and you will see omega-3 fortified eggs, probiotic yoghurt drinks, sleep-inducing milk and selenium-enriched bread. So-called functional foods, also called nutraceuticals, are a booming market, and Britons are among the most enthusiastic consumers of them in Europe.

According to market analysts Datamonitor, the average UK customer now spends £110 a year on functional foods. The number of people buying such products has doubled in the last five years alone, and is set to exceed five million by 2007. Even firms such as Cadbury-Schweppes are in on the act, with the launch in the US last year of 7Up Plus - a fizzy drink fortified with calcium and vitamin C. In an interview last month with the trade journal New Nutrition Business, Brock Leach, chief innovations officer for PepsiCo, said: "Wellness will be to the food business what convenience has been over the past 15 years."

Last month, Waitrose launched a loaf of bread fortified with selenium, a mineral that has been shown to boost the immune system, regulate blood pressure and reduce the risk of cancer of the breast, prostate and colon. Benecol margarine, Yakult yoghurt drinks and their ilk are now multi-billion-pound international brands, as consumers buy the line that additives in food can be good rather than bad for them.

Such is the excitement about the health-giving properties of some of these products that a Dutch insurer is now reimbursing policyholders who buy cholesterol-reducing products from the Becel pro.activ brand.

Dr Frost is wholeheartedly in favour of functional foods, but says that some of the claims may not be well substantiated. "Some of these products have a lot of very good science behind them, while others are making some very dubious claims indeed."

Concerns around some of the beneficial effects being touted by manufacturers have prompted the EU to introduce legislation on exactly what it is that products can lay claim to. The new laws are likely to be brought in during Britain's presidency of the European Union, in the summer of this year.

There are also worries that people may become complacent about taking active steps to improve their health if they believe they can simply buy a tub of margarine to ward off problems such as heart disease. Spreads such as Benecol contain plant sterols that can block the absorption of cholesterol during the digestive process. In clinical trials, people who ate margarines with plant sterols three times a day as part of a controlled diet reduced their cholesterol by up to 15 per cent. However, when supermarket consumers took part in a study, they ate the spreads in a much less controlled way and only reduced their cholesterol by about seven per cent. The British Heart Association has warned people with potential heart problems that these products are no substitute for exercise and a good diet.

Anyone who has seen Jamie Oliver desperately trying to tempt schoolchildren from fat-laden Turkey Twizzlers to his spicy chicken wraps in his latest television series will know that the fight against obesity has no easy solutions. But if industry and health campaigners start singing from the same hymn sheet, functional foods could be a key part of the battle of the bulge.


The market in functional foods is now worth millions of pounds in Britain, but do the health benefits live up to the claims made by the manufacturers?

Dr Gary Frost, head of nutrition at Hammersmith Hospital in London, assesses some of the latest products.


The science: The milk comes from cows who naturally produce higher levels of the hormone melatonin during the morning milking session.

Melatonin is found in the brain's pineal gland and helps to control our body clock and aid sleep.

The verdict: Dr Frost says, "I don't think there is any science or proper research behind this one. We still do not have a full understanding of how some of these processes work."


The science: Studies have shown that selenium can help to boost the immune system, regulate blood pressure and reduce the risk of certain types of cancer. Much of the population is thought to be deficient in this mineral.

The verdict: Dr Frost says foods like this, "can play a real part in a healthy diet. But just because something is enriched with vitamins does not mean that it will improve your wellness or reduce your risk of cancer."


The science: Also found in fish oils, omega-3 fatty acids can improve the health of the brain, eyes and heart. Many people do not eat recommended levels of fish, and eggs enriched with omega-3 can boost intake of fatty acids.

The verdict: Dr Frost says, "These can have a benefit, but people have to be aware that just because a product is fortified with something, it doesn't necessarily mean that it is going to do you any good."


The science: Contains plant sterols that occur naturally in some foods, such as fruits, nuts, seeds and cereals.

Plant sterols are identical to cholesterol in their chemical make-up and work by blocking the absorption of cholesterol from food during the digestive process.

The verdict: Dr Frost says, "I think there is real scientific evidence that they can have health benefits and reduce cholesterol."