People opt for a healthier lifestyle at 45

According to the study, it`s 45 years when more than a third opt to limit drinking to three or fewer units a week, a similar proportion avoid processed food, while more than eight in 10 eat the recommended five pieces of vegetables every day.

Nine in 10 are also non-smokers, compared to three-quarters of people under 45, and nearly 40 per cent say they "never over-indulge in food or drink at the weekends", a rule just one in six younger people stick to.

The Health of the Nation study, commissioned by new supplements company Bioglan, was based on a survey which questioned 5,000 people aged 16 and over, the `Daily Mail` newspaper reported.

The survey found the age of 45 was linked to a decline in health, with a third of people at that age reporting they suffer joint pain, one in five having high blood pressure, and one in 10 experiencing shortness of breath.

At the same time, there was a marked increase in concerns about ailments including heart disease, dementia and stroke, with around half of those midway through their fifth decade fearing for their health, it found.

Almost six in 10 of this age group re-evaluated their prospects after suffering a health scare, while four in 10 took stock after a family member was taken ill.