Over the past two decades, obesity levels in Europe have been steadily increasing, tripling between 1990 and 2006, according to World Health Organization (WHO) statistics. But measuring the phenomenon is the easy bit. Understanding it is much harder, and researchers have struggled to explain the physiological effects of appetite on obesity.
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However, thanks to a European Union (EU)-funded research project, new insights are emerging into the complex relationship between hunger and feeding. The research is expected to help businesses develop foods and diets that are better adapted to body weight control.
The 'Nutrient Sensing In Satiety Control and Obesity' (NUSISCO) project offered nine PhD students the chance to research the latest experimental, theoretical and applied science of feeding and appetite with London's Imperial College, Munich's Technical University (TUM), the French food and science institute AgroParisTech and multinational Unilever.
Launched in June 2006, the four-year long NUSISCO received a €1.65 million grant as one of the Marie Curie Actions (MCAs) EU's programme of support for the mobility of researchers. "The project began with the aim to research feeding behaviour," says, Daniel Tomé from AgroParisTech, who was the project coordinator. "There was a need for expert scientists in this area for both industry and academic research. We felt that a synergy between the different partners in a Marie Curie doctoral programme would meet this objective."
Tomé says the research was able to benefit from the complementary expertise that the four partners offered in key research areas like molecules and cells, integrative physiology, human clinical science and food development.
The nine PhDs were all able to use their experience gained during their Marie Curie fellowship as a springboard to their next positions. Six of them are in post-doctoral positions: Wageningen University in the Netherlands, Imperial College London, University of Surrey in the UK, Marseille University, University of Paris, and University of Dublin. Another was appointed assistant professor at the American University in Beirut, while two others were recruited by food giants Nestlé and Danone.
The research itself revealed the importance of the interactions between the different appetite regulation signals in the brain. This is crucial for understanding food and diets, and is an area that is set for further research in the coming years, Tomé says. "The main objective was to get more knowledge on the peripheral signals sent to the brain during meal ingestion and how these signals are treated by the brain to control the food intake," Tomé says.
Among their findings were that neither stress nor artificial sweeteners have an effect on appetite regulation, and that fasting biases brain reward systems towards high-calorie foods.
But the main discovery, Tomé says, came from understanding the different way that the brain processes the eating of different foods. "Despite the complexity of the peripheral signals produced by food intake, specific messages are recorded at the brain level related to digestion and the composition of the meal," he says.
As for the students, Tomé says NUSISCO gave them invaluable insights into the latest research on food, appetite and hunger. The network of collaboration between the different European partners continued after the project formally ended, and was often crucial for the researchers as they moved on to careers in academia and industry. "The training and research helped develop innovative activities between academic research and food industry," he says. "It also created a unique European network of expertise on feeding behaviour and satiety."