Today's average 40-year-old is closer to the age of 30, according to research found by a health insurance group.

The group said that in comparison, younger generations with unhealthy lifestyles are feeling older than their years.

Research from the health insurance provider reveals that younger generations of British adults, those in their twenties and thirties, lead less healthy lifestyles than those aged 40 or older.

The study also shows that 44 per cent of Britons feel younger than their actual age, with the nation's 40 year olds saying they feel 11.5 years younger, on average leaving them with an age of 28.5-years-old.

Additionally, the research highlighted points such as greater stresses and strains of modern life, compared to that of their older counterparts as a factor of diminishing health. Younger generations are being worn down by questions of old age and fears of being 'over the hill' when one reaches a certain age.

Today's 20-somethings feel three years older than their age, on average, 30 years old generally feel their actual age.

Swinging sixties overtaking the 20-somthings

The average Brit in their twenties or thirties have less energy even than those in their sixties, the study found, with more younger people reporting a dip in their energy levels throughout the day than older Britons. 12 per cent of 30-somethings do not feel energetic at any time of the day, compared to just six per cent of people in their sixties.

From its research the firm has deduced that 40-years-old could be the turning point when it comes to health and wellbeing, because people in their twenties and thirties do not live such healthy lifestyles as those in their forties and fifties, which could account for their low energy levels.

An unhealthy diet, lack of exercise and not getting enough sleep are the top three reasons for a lack of energy, it explained, and only 47 per cent of the younger generations say they eat a balanced diet, 18 per cent do not get any exercise, and 25 per cent get fewer than six hours' sleep a night.

The study also revealed other facts about the lifestyles of the different age groups, and found that a higher proportion of younger people smoke, struggle to eat their five fruit and vegetables a day, and regularly eat takeaways.

Wellbeing can come with age

Speaking about the findings, Shaun Matisonn, the CEO at the insurer, said: "While it's wonderful to see that the older we get, the better we feel, the energy levels of those under the age of 40 clearly needs more attention. This age group need to get more exercise – and more sleep - eat healthily and follow more active lifestyles to help boost their energy levels."

Mr Matisonn added: "Finding time in your 30s to exercise and eat healthily can be especially difficult while you're juggling a career and looking after a young family, but incorporating small steps in your daily routine, such as getting off the bus a stop early and snacking on fruit rather than crisps, can help make all the difference."

Reports that were published recently also show that young people today are less healthy than people their age, ten years ago.

The findings which were reported in the British Medical Journal, shows that girls are nine per cent unhealthier than their counterparts 10 years ago, while boys today were found to be 7 per cent unhealthier than a decade ago.