Average American believes they hit peak health at 34 – and old age begins at just 42, survey claims

They say 40 is the new 20 — but most Americans believe they peaked physically at 34, according to a survey.

And the majority of people start to feel old at just 42.

That is according to a poll of 2,000 Americans across four different generations — Gen Z, millennials, Gen X, and baby boomers.

Joint pain was perceived to be one of the top warning signs of old age, as well as a slower metabolism and middle-aged spread.

New York pollster OnePoll carried out the survey for weight loss firm named Found, which is based in California.

Participants were interviewed between September 1 and 12 this year and were from across the United States.

An equal number were Gen Z (18 to 25 years old), Millennials (26 to 41), Gen X (42 to 57) and baby boomers (58 to 76).

The majority said they believed signs of aging struck at 42 years — including joint pain, gray hairs and a slowed metabolism.

Some 15 per cent, however, said they had noticed signs of aging before their 35th birthday.

A majority also said that they believed 34 years old was when they expected to be at the peak of their physical and mental fitness.

Additionally, one in five participants said they were happiest in their 20s and 30s. 

Dr Rekha Kumar, the chief medical officer at Found, said: ‘While aging is inevitable, making healthy changes to your lifestyle are preventative care measures that can help mitigate age-related issues like weight gain and chronic conditions. 

‘Over the past 100 years we have nearly doubled life expectancy, so it’s crucial to be proactive about extending our health span as well as our lifespan.’

She added: ‘Programs that incorporate guidance to not only help people manage their weight, but also improve overall lifestyle habits, such as improved sleep, daily movement or taking care of their mental health, can help people maintain their health as they age.’

American life expectancy has been rising for decades and reached a peak of 76 years for men and 80 years for women in 2019.

But amid the Covid pandemic and strain on health systems it has dipped with men born in 2021 now expected to live 73 years and women 79 years.

Aging is a natural process that affects all humans and living things.

It is caused by the gradual accumulation of damage to cells over time, and the deterioration of their function.

These changes are initially slow, but begin to accelerate in later years.

Muscle mass rises throughout the mid-20s, but thereafter begins to decrease.

Skeletal mass also rises until the age of 30, before also beginning to drop first around the pelvis and spine and lastly in the fingers and toes.