'My biological age is beyond that of my years'

Who are the scientists and thinkers forging new paths for humanity? On our new podcast, Brave New World, David Walliams meets longevity expert Dr David Sinclair

- David Walliams

I FIRST realised I was unfit when I joined secondary school. Once a year we had to take part in the dreaded cross-country run. The overweight boys like me would always be left behind. So, we made a pact to walk the course instead. The rest of the boys had already changed and were waiting by the finish line, jeering us as we came into sight - at which point we all burst into a sprint to avoid being the last one. That was the ultimate humiliation. It was the Eighties, a merciless time.

Food has always been a solace and a refuge for me. Speaking about bulimia, Princess Diana came up with one of the most powerful evocations of comfort eating: "Like two arms wrapping themselves around you." When I had a bad day at school, I was more likely to eat 10 biscuits that evening instead of two. This is why being overweight is often a chronic condition: you are finding comfort in the very thing that is making your situation worse. But food is also one of the great joys of life. I have a 10-year-old son and we like to eat together. Food that 10-year-olds like: roast chicken, pasta, steak and chips. It's not the healthiest, but it makes us happy.

Now I am 52, and despite my sedentary lifestyle writing books and scripts, I try to keep fit. I walk my dogs, swim and go the gym a few times a week. But I still eat too much. Some might say that I over-indulge. One such person is Dr David Sinclair, a brilliant scientist at the forefront of the longevity movement, which has gained serious momentum these past few years. I was introduced to Dr Sinclair by my two-bearded friend Evgeny as part of his podcast, Brave New World, and volunteered to take part in an experiment that would identify where my big wobbly body needed help.