Race to find way to fool our feelings of fullness

Appetite suppresants will help combat growing obesity. Picture / Nigel Marple.

UNITED KINGDOM - Even its most ardent enthusiasts admit that Hoodia gordonii is an unappealing plant. It takes five years to mature, requires temperatures above 40C to grow and the end result is a particularly spiny cactus with a bitter taste.

But this prickly plant - along with a host of other unlikely natural substances from Korean pine nuts to Scottish wild peas - is at the forefront of an increasingly competitive race to cash in on the world's £100 billion ($294 billion) obesity epidemic.

Three of the biggest food conglomerates, Anglo-Dutch firm Unilever, France's Danone and America's Kraft, are urgently investing millions to produce foods that will achieve the hallowed goal of making people eat less.

The new buzzword in the food research laboratories of the multinationals is "satiety" - the science of duping the brain into feeling the body has a full stomach by suppressing appetite.

Gary Frost, professor of nutrition and dietetics at Surrey University, said: "This is an area with a huge amount of activity. It is producing some very interesting science with fairly sensational results.

"There is a sense that for the company or companies that can isolate a proven appetite suppressant, there is market waiting that would [include] the vast majority of the population. It is a glittering prize but a controversial one - can you confidently say that one food will halt your desire for another?"

For the winner of this hi-tech competition to isolate satiety-inducing compounds, the "prize" is indeed glittering.

There are now 300 million overweight and obese people in the world, and billions of health-conscious consumers, for whom premium "nutraceuticals" which allow people to eat themselves thin would be a godsend.

Which is why, in a market already flooded with bogus diet "miracle pills", Hoodia gordonii is the target of an investment programme, worth a potential £21 million, being run by Unilever to turn the ugly South African cactus into a food additive which tricks the brain into thinking the stomach is full.

The company has confirmed it is progressing with full clinical safety trials of P57, the active ingredient isolated from the cactus. Early trials showed that those taking P57 could cut their consumption by as much as 1000 calories per day. The average calorie total for an adult man is 2500 per day.

So far it has paid £10 million to Phytopharm, a Cambridge-based bio-technology company, to develop and test the closely-guarded compound, which sends messages to the hypothalmus - the part of the brain that controls appetite through the excretion of hormones - that the stomach is full.

The Anglo-Dutch company, which also makes the diet product SlimFast, is investing large sums in an agronomy trial to grow commercial quantities of Hoodia gordonii, which hitherto has only grown wild in the Kalahari desert.

The cucumber-like core of the cactus has been used for millennia by indigenous San tribesmen to stave off hunger pangs by eating it on long hunting trips.

Unilever has struck a deal with the San to pay the impoverished tribes a royalty from the sales of any product containing P57, to be used in a social programme.

The cash and energy being pumped into Unilever's project represents just the latest manifestation of mankind's search for a way to control hunger pangs.

Researchers are also looking at the heath pea, which was munched by Roman legions on campaigns against the Scots. With the blessing of Scottish Natural Heritage, London-based businessman Richard Swift plans to investigate the plant as a potential slimming aid.

Lathyrus linofolius, as it is otherwise known, used to be a staple supplement to the Highland diet when food was scarce.

But Unilever and Swift are not alone in this increasingly crowded field. Danone, which owns brands including Evian and Actimel, has patented new types of dietary fibre which slow the passage of food through the digestive system, literally making people feel full for longer.

Kraft, the world's second largest food company after Nestle, is working on a special form of starch which resists being broken down by the body, again designed to create the sense that the stomach is full to bursting.

The market is also attracting smaller specialist bio-technology companies eager to take a share of the vast unfolding market.

A Dutch company, DSM, last month began marketing yoghurts in Portugal containing Fabuless, a patented emulsion of palm and oat oils which claims to reduce appetite by up to 25 per cent. Another firm, Lipid Nutrition, has developed a satiety additive derived from pine nuts found only in Korea, Japan and Manchuria while yet another compound, made from chicory roots, is being researched by a Belgian team.

Many of the substances, including P57, work by affecting a mechanism in the ileum, part of the lower intestine, where the presence of fat triggers a response of satiety to the brain. This "ileal brake" is triggered or mimicked by the compounds by disguising the fat molecules until they reach the ileum. In one case, the body is convinced it has consumed the equivalent of 500 calories when in reality it has had just 190.

But a more basic potential problem exists. Can the signals passed to the brain by the stomach be over-ridden by a pair of eyes attracted by a box of chocolates.

Professor Frost said: "The factors that govern appetite are extremely complex. There is a trigger which tell us when we're full but that can be usurped by the same response that has always allowed humans to eat to excess in times of plenty to get through periods when there is less."

The scientists accept this "squirrelling" factor is almost impossible to avoid but insist the feeling of fullness will still be a lucrative selling point.

- INDEPENDENT