A growing body of research suggests that cooking our own food could be the secret to a long and healthy life Whenever Dr Yasmin Razak sees a healthy patient in their 90s at her London GP surgery, she has a question for them. “I ask what they do to look after themselves. They say every time: ‘I make my own food and I don’t eat out’. They either have an allotment or grow food in their garden.” For anyone searching for the secret to long life, the answer looks straightforward, then. Dr Razak’s nonagenarians, who also cite regular walks, do not rely on the convenience foods, takeaways and ready meals that form a staple of so many British diets today.