How obesity can lead to type 2 diabetes

Dr. Sam Virtue

In our third instalment of interviews with University of Cambridge scientists, Dr. Sam Virtue, from the Department of Clinical Biochemistry Metabolic Research Laboratories, talks about why he became a scientist and describes his work investigating why obesity causes diabetes.


Obesity is the leading cause of type 2 diabetes. In the UK, 29% of adults are obese and there are 3.2 million diagnosed type 2 diabetics. This epidemic of diabetes causes 23,000 preventable deaths and costs the UK economy £39 billion each year.

Globally, nearly 2 billion people are overweight and there are over 80 million diabetics in China alone. It is not an exaggeration to say obesity and the diseases it causes are the most serious medical problem now faced by the world.

We have become used to the idea that obesity causes every disease under the sun, however why it does so is still unclear. We know it isn’t the weight; carrying a 40kg backpack around does not make you sick it makes you fit and healthy! Our lab focuses on the idea that the problem is fat itself.

Fat tissue is not a bad thing – it is our body’s long term energy store. When it works well it locks up the fat we eat and stores it safely until we need it. We think that as people get fatter, at a certain point, their fat tissue stops working. When this happens fat goes to other organs (like the liver) where is builds up and poisons them. We try to work out how to keep fat working well and therefore prevent obesity leading to diabetes.


I always had a love for science from a young age. My first inspiration was the rarest of things (at least 30 years ago) – a primary school science teacher called Mr Olson. He would come in and make science fun and exciting.

While I was always keen on science, I did not really know which direction I would go in. I loved physics, chemistry and biology equally, but I think most of all I loved maths. When I got to the age of 16, I chose to study the International Baccalaureate. You study 6 subjects but they have to be varied including English, a foreign language, a humanity, mathematics, a science and one of your choice.

This meant giving up a science and I dropped physics. All our teachers were great and brought their subjects to life. I went on to study Natural Sciences at Cambridge, which is a wonderful course as you do not specialise till your third year. Many students apply to Cambridge to study physics and end up going on to get biochemistry degrees. I think having studied a broad range of subjects is a valuable grounding for actually being a research scientist. The project you start may have little resemblance to what you end up publishing.

My advice to anyone wanting study science is simple – if you love it and are curious, it is a fantastic thing to do, both as a subject and ultimately for a career. Oh, and do maths for as long as you can! I cannot remember the chemistry and biology that I learnt when I was 16, but I used the mathematics last week!

Check out our other inspirational scientist interviews with Taylor Uekert about her work turning plastic waste into fuel with sunlight and Demelza Wright from the Department of Physics, on how she is working to turn the greenhouse gas, carbon dioxide (CO2), back into fuel.


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