Can your body be older than your age?

While age is usually thought of as just the number of years you’ve been alive, people with identical ages often look – and seem – very different. In 2015, scientists at King’s College London published research suggesting that measuring the activity of around 150 specific genes gives a measure of ‘biological age’ linked more strongly to longevity than mere chronology. But genetic activity is only one factor differentiating biological and chronological age. Exercise, diet and weight can also make a big difference. This has led to various questionnaires – such as the BBC’s online quiz ‘What’s My Real Age?’ ( bit.ly/age_quiz) – which can give clues about your current ‘real’ age, and offer advice on what you can do about it. When using these quizzes, do bear in mind that some of the measures are still controversial.