Being a twin is weird. As a medical doctor with a public profile and a PhD involving genetics, it is strange to have a clone of yourself wandering through the world. We embrace the confusion when people mistake us for each other. The state of twinness is an oddity, but it’s one of the most wonderful things in my life.
Our baby brother Jonathan is the glue that binds us. He’s in his early 40s and more easygoing than we are. He’s the carbon rod in the nuclear reactor, soaking up neutrons, stopping it from melting down. When Xand, my twin brother, and I get into a huge, pathetic row he defuses the bomb in his funny, charming way.
The three of us love each other intensely, but we still regress to our childhood and have humiliating physical fights. Last time it was Jonathan and I, high-kicking each other like Hugh Grant and Colin Firth’s characters in Bridget Jones’s Diary.
My mother-in-law, who is a retired Freudian psychoanalyst, said “advice is an uneasy commodity”. It has modified what I say as a broadcaster. Instead of advice – which people basically hate – I try to impart information, or a perspective, in a neutral way.
I do not care what you eat. I’m portrayed as someone who thinks people should eat different food as a kind of moral or normative statement, but I don’t. I believe that everyone should have the opportunity, freedom and information to do what is best for them.
The secret to a happy relationship, in my case, was the anterior good luck of marrying the correct person. So much of everything in my life is blind, unwitting good luck. It gives you a sense of walking on a high-wire, because luck can end and you don’t always feel in control of it, but my wife is endlessly tolerant, understanding and decent.
Dr Michael Mosley’s “start small” approach influenced me to start exercising again after falling out of the routine when I had children. It’s about setting achievable and long-term goals. I try to do one press-up each day, which generally leads to 10, and every year I run the Hackney half marathon.
Everything I advocate for is about limiting industrial power over the food system. You cannot imagine the pervasive and subtle ways that some transnational corporations affect human health. Poor diet is now the leading cause of early death globally, and we have very little ability to turn away.
No family needs to hear what they should do about buying and eating unhealthy food. If they are struggling, they should not feel responsible. It is the companies that are driving these problems and it requires political change. I send them love, sympathy, and say ‘you are not the only ones’.
I’m a bad pilot and I’m a pacifist. I learned this at medical school when I joined the air squadron and learned how to fly planes. I knew quickly that I was not going to be able to drop bombs. The world is a safer place for it.
The Royal Institution Christmas Lectures will be broadcast on BBC Four and iPlayer on 29, 30 and 31 December at 9pm