Fighting temptation

Obesity in Europe has reached epidemic proportions, according to the World Health Organisation. If nothing is done, there will be 150M obese adults, 20% of the population, by 2010 and 15M obese children. And with 30%-80% of adults overweight in most countries, Euromonitor International is forecasting that satiety could be the next big health and wellness trend. The good news is that food manufacturers will be able to repackage and relaunch low-GI and low-carb foods as high-satiety foods and ingredients, says Simone Baroke, Health and Wellness Analyst at Euromonitor.

But it isn't solely about maintaining a feeling of fullness. The whole business of finding and formulating palatable ingredients that actively help the body to regulate and control dietary energy intake is poised for take off.

But do they work? Do the claims eally stand up? Dave Mela and Eva Kovacs, of the Unilever Food & Health Research Institute in The Netherlands, recently looked at the effectiveness of a range of popular metabolically active functional food ingredients for weight control. They examined the claims for CLA (conjugated linoleic acid), which stimulates the breakdown of stored fat in fat cells; diglycerides and triglycerides; green tea extract (an appetite suppressant); ephedrine (a stimulant similar to synthetic amphetamine and an appetite suppressant); caffeine (a stimulant and appetite suppressant); and capsaicin, the hot stuff in chilli peppers that increases your metabolic rate and thus burns off fat and reduces bodyweight.

And their conclusion? There were gaps in the clinical evidence and the knowledge of the mechanisms involved. The science wasn't there yet, they suggested, to enable ingredient manufacturers to specify the dietary conditions and food compositions in which such ingredients could be of most benefit for weight control.

Dr Mela said: "We see many companies promoting supposed weight control ingredients with claims which we simply do not believe are justified.

"We are also seeing products where potentially active ingredients are present, but in a quantity too low to be of benefit.

"The majority of food supplements marketed for weight control are probably ineffective. Only a few of the supplement ingredients have migrated, in a rather limited way, from supplements to mainstream foods. This is mainly because of issues relating to the standard of supporting evidence required; the regulatory and safety requirements for foods; and feasibility, in terms of sourcing, cost and effects on product quality.

"In weight management it is not very easy or cheap to find effective, feasible ingredients and prove that they really work. That is a major scientific challenge."

According to John Kurstjens, global marketing manager for Lipid Nutrition, which produces Clarinol CLA, there are many ingredients on the market that make very strong claims but which have hardly any scientific support.

"Our mission is to develop lipid ingredients [fats] which have health benefits for humans. And our ingredients are scientifically proven - that is the way we differentiate ourselves from all the other ingredients on the market."

Last year Clarinol CLA (derived from safflower oil) was given clearance by the US Food and Drug Administration to use four health claims. It reduces weight gain, increases lean muscle mass, reduces body fat and maintains body weight level. "It works by reducing the amount of fat taken up by the fat cells in the body," says Kurstjens. "It blocks fat cells and stimulates more fat-burning."

Clarinol CLA has just been introduced in Germany as a one-shot yoghurt drink sold through supermarkets, says Kurstjens.

"Our other ingredient is PinnoThin - a pine nut oil. It stimulates two hunger-suppressing hormones in the gut - CCK and GKLP1 - to give a feeling of satiety. PinnoThin is very new but a lot of food companies are doing projects with it and we are waiting for the first product to be introduced."

Cognis recently rolled out a study into its Tonalin CLA product (also produced from safflowers) showing that it could prevent weight and fat gain. Daily supplements could reduce body fat while protecting lean body mass - often a casualty of low-calorie diets. And other studies have demonstrated increased feelings of satiety and improved mood as well as a reduction in the degradation of muscle protein, says Cognis.

It sees a growing trend for ingredients traditionally used in supplements to be introduced into foods. "There are challenges for those developing weight-management ingredients," says Dr Ralf Zink, director of global R&D at Cognis. "Regulatory issues and consumer confidence are two major issues - both of which can be addressed by credible science."

Meanwhile, Belgian ingredients company Orafti has been looking at the effects of its Beneo oligofructose and Beneo inulin prebiotic dietary fibres in controlling satiety.

Over the past five years it has undertaken two studies to determine what effects oligofructose (a sugar replacer) and inulin (a fat replacer), both obtained from chicory root, have on satiety.

And, according to Christine Nicolay, marketing manager for Orafti, people who eat Beneo oligofructose stay without hunger for much longer. "And when they eat their next meal they consume fewer calories than the control group," she says. A third study is going on at the moment into its effects on obese people."

Jeya Henry, professor of human nutrition at Oxford Brookes University, UK, says: "You can only put on weight if you are in positive energy balance. So we have to look at how we can reduce our food intake or increase our energy expenditure so that we are in zero balance or negative balance."

There are foods that can increase energy expenditure - so-called thermogenic foods which increase the body's metabolic rate. "We were one of the first to demonstrate - certainly in the western world - that the compound capsaicin increases metabolic rate," says Henry. "It has got a thermogenic response. Other foods that we know that cause thermogenesis are mustard, coffee, chilli and horseradish and ginger - broadly all are what I would call condiments.

"We are just scratching the surface of a whole range of foods that have a thermogenic effect. The challenge for food ingredient manufacturers is to systematically look for compounds that are both thermogenic and palatable.

"But the real challenge, and the real reason that there is a reluctance on the part of food manufacturers to grab on to these things, is: how can you patent a chilli powder, how can you patent horseradish, how can you make money out of it?"

The other half of the energy balance equation is to reduce food intake - and that leads to appetite suppressants, says Henry.

"We now know that foods with a low GI (glycaemic index) give you appetite suppression. We know that eating a large fibre-based meal gives appetite suppression. And we know that viscous foods give you appetite suppression.

"But food companies are now so specialised that they don't put two and two together."

The result, suggests Henry, is a lack of scientific expertise in general nutrition. "We need specialists but we also need people who have a broad picture. And we need to get food companies to talk to each other. The future is for collective research and collective use of ingredients."