Happiness begins at 40 for women: Fairer sex most confident in fifth decade - Julia Roberts, Nicole Kidman, Catherine ...

Nicole Kidman (45) and Julia Roberts (45) should now feel just 35
Some 17% of women in 40s say sex life is better than ever
Almost 60% of women still confident enough to wear a bikini

PUBLISHED: 05:06 EST, 9 April 2013 | UPDATED: 07:28 EST, 9 April 2013

Life, they say, really kicks off at the age of 40. And it appears that for women this really is the case.

The fairer sex is more content, satisfied and fulfilled when they hit their fifth decade than at any other age - and even feel some 10 years younger than they actually are - according to a new study.

So stars such as Nicole Kidman (45), Julia Roberts (45), Catherine Zeta-Jones (43), Selma Blair (40) and Geri Halliwell (40) will be feeling more vibrant and youthful now than they were in their early and mid-thirties.

Nicole Kidman, 45

Julia Roberts, 45

Actresses Nicole Kidman, left, and Julia Roberts, right, are both 45 years old

More than half of women over 40 (55 per cent) also say they are more confident in their appearance than when they were in their thirties. And a 86 per cent insist 40 is now the new 30.

With many saying they feel rejuvenated, 17 per cent put this down to having a better sex life than ever before, while 27 per cent say their dress sense is better than ever.

Today's women in their forties are happier in a wider range of clothes than ever. ! The research by health food company Linwoods Superfoods found nearly two thirds - 59 per cent - still feel confident enough to wear a bikini.

And 60 per cent insist their generation should still feel happy wearing figure-hugging tops or showing a glimpse of cleavage.

The study by health food company quizzed 2,000 women aged 40 to 65 about their lives to discover the effect of passing the milestone.

It seems many insecurities are banished as women hit their forties, with an overwhelming 81 per cent saying they are happier in themselves than younger women.

Selma Blair, 40

Catherine Zeta-Jones, 43

Actresses Selma Blair, left, 40, and Catherine Zeta-Jones, right, 43, should now feel more confident, secure and happy with themselves than they did a decade ago

This may be due to almost a third, 32 per cent, being more financially secure than ever, while 48 per cent said they were in a stable relationship.

'Not only are women of 40 still full of energy, they are enjoying lives full of promise and possibilities'

Actress Samantha Womack, 40, who played Ronnie Mitchell in Eastenders, said: 'The days when your 40th birthday represented the start of a slow descent into a quiet middle-age are long gone.

'Not only are women of 40 still full of energy, they are enjoying lives full of promise and possibilities.

'Women who are 40 and older are not slowing down, with many having babies, caring for children, supporting their own parents and working hard to maintain careers.'

Geri Halliwell, 40

Samantha Womack, 40, says women of her age are enjoying lives full of promise

At 40 years old both Geri Halliwell, left, and ex-EastEnder Samantha Womack, right, should be feeling more like 30-year-old spring chickens

Joanne Hayden from Linwoods Superfoods said: 'These survey results reinforce that age really is just a number.

'I feel like a stronger person and I care much less what others think. I'm more confident in my work, my relationship and motherhood'

'Women of 40 and over are as full of life as ever and feeling fabulous has much more to do with how satisfied you are in life, from organised finances to a healthy diet, small changes can make a huge difference.'

Caroline Harvey, 44, a teacher from Winchester, Hants, said: 'I definitely feel better about myself and my life since turning 40.

'I was more confident in my thirties than in my twenties and more comfortable in myself again now I'm in my forties.

'I feel like a stronger person and I care much less what others think. I'm more confident in my work, my relationship and motherhood.'