Feel full not fat

Diogenes, the Cynic, was a Greek philosopher. Born about 400 years BC, he was a beggar who lived in the streets of Athens and made a virtue of extreme poverty. He is said to have been an austere ascetic, railing against the consumer society of his day, "his clothing of the coarsest, his food the plainest, and his bed the bare ground"

An apt choice of name, then, for a major European research project targeting one of the excesses of today's consumer society - obesity.

Obesity and its associated medical problems are reckoned to cost Europe anywhere between €70bn and €130bn a year in health care bills - 5% of the EU's total health care budget.

The solution would seem to be a simple case of getting our food energy balance right. But there are big challenges in identifying and delivering the most effective advice and tools for preventing weight gain. Also, there is considerable genetic variation in our susceptibility to getting fat, and our lifestyles don't help much, either.

So, how do we solve Europe's obesity crisis? Enter Diogenes. Not a smelly, old, dead Greek beggar, but Diet, Obesity and Genes - a €20M European research project into obesity (www.diogenes-eu.org). Now half-way through its five-year remit, Diogenes is one of the largest and most ambitious projects on obesity. It involves 34 partners in 15 European countries with the active participation of four multinational food companies - Danone, Kraft, Nestlé, and Unilever.

Its aim, says Wim Saris, Diogenes project director, is to study the dietary, genetic, physiological and psychological factors that make 10% of Europeans too fat. The main thrust of the programme is to look at the role played by dietary protein and carbohydrate in enhancing our feeling of satiety and satiation.

A DNA bank of over 13,000 individuals is being used to research what genetic factors affect obesity, while the behavioural characteristics and the physiology of satiety and satiation will also be studied.

The project is highly interlinked and the hope is that it will lead to innovative food products, new diagnostic and predictive tests for both professional and consumer use, as well as better dietary advice.

Diogenes has five research themes - so-called Research and Technological Development lines or RTDs. RDT1 is using a large intervention study to examine the effects of glycaemic index (GI) and protein content on weight gain. RTD2 aims to identify molecular bio-markers and predictors for weight gain and metabolic variation. RTD3 is an epidemiological study of obesity, genes and diet among the population as a whole. RTD4 is studying consumer attitudes and behaviour to food.

RTD5 is more practical. It is looking to food technology to develop novel food ingredients that trigger satiety and increase satiation - and which are nice to eat, too.

The main pillar of the Diogenes project is the RDT1 weight loss study. This aims to identify which diets are most effective in preventing weight gain. It is looking at the effectiveness of diets with varying glycaemic index and varying protein contents - both of which have been shown to affect calorie intake by influencing the feeling of being full.

The research is being carried out on 400 volunteer families who have all been put on a low-calorie diet and have lost weight. Now they are about to be put on one of five different diets combining high or low GI and high or low protein content. The families will be allowed to shop (for free) in two special research supermarkets so that their food intake can be accurately monitored.

The volunteers will now try to maintain their weight loss over a six-month period. "The trouble with most diets is that you put back on more weight afterwards than you lost. So we want to figure out who responds to which diet and which diet is suitable for which kind of consumer," says Dr Martin Kussman, leader of functional genomics at Nestlé's research centre in Switzerland and sometime stand-in for Saris.

Kussman's group at Nestlé is involved in the genetic side of Diogenes. "It's about how you are genetically predisposed, how are you genetically susceptible to diet," says Kussman. "We are addressing genes that we already know play an important role in energy metabolism - people differ in how they metabolise macronutrients.

"Nestlé, and our competitors as well, have an interest in individualising nutrition, adapting nutritional products to individual needs. That does not mean we want to genotype the consumer so that you print out your own menu! But we do want to understand better who responds to what in their diet. The big question then is how you bring this to the consumer."

It is not all dour diets and glycaemia and genomics in Diogenes. One glorious autumn afternoon last year, members of the Diogenes general assembly were to be found at a barbecue eating sausages. The Hotel Beach Club on the island of Majorca had become the temporary testing ground for the work of RTD5, which is developing foods and meals that regulate food intake.

The barbecue was, in fact, a tasting session and it included two varieties of sausages each containing 40% energy from protein. The sausages differed in the source of protein used, gelatine-based or milk protein-based. Two bread samples were also tasted. One was produced using resistant starch (low GI) and the second was a control sample.

Øydis Ueland made the sausages. Or, at least, she is head of consumer and sensory research at Matforsk, the Norwegian food research institute, which had made the sausages. Ueland leads the RDT5 food technology side of Diogenes.

Matforsk is working with three other food research centres to develop novel foods and ingredients to stimulate satiety and satiation. They are the two Netherlands research bodies, Nizo and the newly named Top Institute (formerly Wageningen Centre for Food Sciences), and Budapest University of Technology and Economics.

"Nizo is looking at flavour and how satiating it can be and how long this satiation can last," says Ueland. So far, she says the results indicate that people have very different personal responses. "It is all to dho with when flavour release occurs - whether it is early in the chewing process or later."

Nizo is still analysing the results, says Ueland, but one possible hypothesis could be that overweight people need to chew more to get the same flavour stimulus as a normal person.

"If this is the case, then the challenge for the food industry would be to increase flavour release so that overweight people would get more stimuli earlier and so wouldn't have to eat so much", she says.

The Top Institute is looking at how macronutrients, such as protein and fat, affect satiety. "They are also looking at perceived satiety from triggers such as capsaicin from chilli peppers and monosodium glutamate and whether these triggers can be added to food products to increase the perception of satiety," she adds.

Budapest University is testing different types of resistant starches to see if they can be used commercially in bread and pasta production to reduce the levels of blood glucose, says Ueland.

"And what we are doing here at Matforsk is making sausages. We are adding additional protein to meat products, such as sausages and meat balls. We are trying to develop new product alternatives with increased levels of protein which people will feel more full from eating so that they will eat less.

"We are now looking at the results. Hopefully, what we will see is that when people are given a high protein meal they feel more full after three or four hours and so eat less at their next meal."

The aim, says Ueland, is to develop food products and ingredients and macronutrients that will make people feel full without consuming more calories.

"We want to provide people with more alternatives," she says.

"It's boring to go on a diet because you have so few product opportunities that you can eat. That is why consumer compliance with diets is low in many cases, especially when you have been on a diet for a long time. We are trying to make it a bit nicer for people."