By Professor Gary Frost, Chair in Nutrition and Dietetics, Department of Medicine.
Food is an aspect of life that constantly challenges the ingenuity of scientists. Its most pressing questions may start out as problems of biology, but only find solutions once chemistry, engineering, psychology and economics have been brought to bear. Most of nutrition isn’t about a single discipline, it’s about bringing multiple disciplines together to work on a problem and that is why at Imperial we have created the Nutrition and Food Network to establish a multidisciplinary approach to tackle some of the world’s biggest health problems.
The goal of the Network is to bring the strengths of Imperial researchers together to focus on food and nutrition research. It is about bringing people with diverse backgrounds together to focus on problems which are associated with diet, many of which are currently intractable health problems, such as obesity and type II diabetes, where there seems to be no solution to the increasing burden. The Network works by posing exciting problems, you can’t force people to work together, but if there is excitement about what you are trying to achieve, then it works.
Although Imperial is not overtly known for nutrition, many groups’ focus is on nutrition and they lead the world. For example, Elio Riboli’s research into cancer has a big focus on nutrition, Jeremy Nicholson’s work with the microbiota has a big overlap with nutrition, and a number of the engineering projects also involve nutrition. So although Imperial may not have been seen as being a major player in the field, in reality it has been. It is this expertise which allows us to look at these important questions on food and nutrition and search out ways to answer them.
Some of the questions that demand this multi-disciplinary approach are apparently simple, such as what people eat at home. This question alone is very difficult, if not impossible, to understand, to the point where most of the big datasets in the UK on this simple question have error rates of around 50%. The issue comes from the fact that people like to present a favourable picture of their eating habits, either deliberately or subconsciously. So you’ve got to have an assessment technique that takes the person out of the equation.
The approach being developed at Imperial combines engineering, nutrition and medicine. Dr Benny Lo from Professor Guang-Zhong Yang’s team at the Hamlyn Centre has designed a tiny, wearable camera that turns on only when a person’s jaws move in the specific way associated with eating. Surface recognition software can identify the food being consumed. Meanwhile Professor Elaine Holmes and Dr Isabel Garcia-Perez, in the Department of Surgery and Cancer, have developed methods to understand the quality food consumed by analysing molecules in urine.
These technologies could work side by side: if we can bring them together, we might start to understand for the first time what people are truly consuming. This will help policy makers who might, for instance, want to reduce diabetes by changing eating habits. We hope that these technologies will give the accuracy needed to understand the impact of public policy. This is also important when it comes to dealing with nutritional problems in developing counties, and alongside Professor Yang here at Imperial we have also been awarded a grant from the Bill & Melinda Gates Foundation to see if this approach and the use of new technology can be used to assess food intake in developing countries.
The range of expertise at Imperial really becomes obvious when you also look at all the research being pulled together by members of the Network, a range that basically covers all areas of the food chain. For example at the beginning of the chain there is Dr Laura Barter, a Senior Lecturer in the Chemistry Department and Director of the Agri-science Chemical Biology research network AGRI-Net, who is working on ways to make food crops more productive through improving photosynthesis. Her research looks at the surprising inefficiencies in photosynthesis and how to improve them. Then there is Marisa Miraldo, Associate Professor in Health Economics at the Imperial College Business School, who works on interventions to encourage healthy behaviour, including healthy eating. She is particularly interested in looking for the behavioural determinants of food choices and, in particular, how ‘economic’ preferences (e.g. risk and time preferences, and self-control) shape nutritional balance and how people react to interventions to curb obesity. An area of obvious importance to policy-makers.
While Dr Miraldo approaches eating behaviour from an economic point of view, Dr Weston Baxter has design in mind. A Lecturer in the Dyson School of Design Engineering, he works on ways that design can modify the way people behave around food. For example, studying how people prepare food in the developing world or use hand washing stations near community toilets has provided design insights that help maintain good hygiene practices such as handwashing. In the commercial context this work has to be less controlling, and one of the most intriguing projects Dr Baxter is working on involves food rituals, such as the way some people always separate the sticks of a chocolate bar in a particular way before eating them. This is interesting because rituals appear to make food more enjoyable.
Once the food is in someone’s mouth, another kind of engineer starts to get involved. Dr Maria Charalambides, Reader in Mechanics of Materials in the Department of Mechanical Engineering, applies knowledge that she developed studying food processing to food consumption. Beginning with the first bite, to look at the food breakdown, the forces on the teeth and so on. Next the aim is to cover the whole process of chewing, which will involve bringing in other engineering specialists, collaborating with fluid dynamicists and tribologists to take the food from the first bite to the bolus that you can swallow. Working out how the food interacts with the mouth cavity? Looking at how it changes phase from solid to liquid and how does it interact with the surfaces in the mouth?
And at the end of the eating process we once again return to my area, digestion and affecting the behaviour of the gut with short-chain fatty acids. The action takes place deep down in your colon, which is highly inaccessible, it was always a problem getting anything to travel there, because the body is very good at breaking stuff down. But together we have found the solution, which was to fix the short-chain fatty acid, in this case propionate, onto a common dietary fibre called inulin to produce a food supplement. It delivers a certain quantity of short-chain fatty acid into the colon, and you can get predictable effects on appetite regulation. To continue this research my team has been awarded a grant from the National Institute for Health Research for a randomised control trial to see if this supplement prevents weight gain in people between the ages of 20 and 35. If it works we hope we can really start to make a difference in the ongoing issue of obesity and the health complications that come with it.