Good question! In the days when people only expected to live to about 45, middle age started earlier. Until quite recently, it was usually considered to start at around 40, and anything over 60 or 65 was old (the pension was known as the Old Age Pension.)

Now that people in many countries expect to live to 80 or more, 40 is much less likely to be seen as middle age. At this age, it's quite common to be starting a family or changing career - and if you've looked after yourself you will more than likely have the same health and energy, that your grandparents may have had at 30.

I would put the new middle age at around 50 (but that's probably because I haven't reached it!) For many of us, this is now the age when you feel you've got to a steady point in your career, relationships and family life. Old age doesn't really begin now until over 70, as people remain active for much longer.

What do you think middle-aged means?