Joan Sewell is an American woman who wrote a funny book called “I’d Rather Eat Chocolate: Learning to love My Low Libido.” In an interview about the book, Sewell grumbled about her low sex drive and mentioned a conversation with a woman who described herself as a juicy tomato. “If you were a vegetable, what would you be?” the interviewer asked. “I don’t know, maybe a celery stick,” she replied.

When I speak in public I tend to focus on the celery sticks, making the point that most women end up with low libido in long term relationships. But I always explain there are also juicy tomatoes out there – one in ten of the 98 couples who took part in my research for The Sex Diaries included women who wanted more sex than their partners. And boy, is that a struggle for them.

Four out of the ten women broke up their relationships during the year they were writing for me, unable to deal with their feelings of rejection, their isolation at finding themselves with a man who can’t match their desire. What made matters worse is they were usually surrounded by friends who complained of partners who won’t leave them alone.

When I include Sewell’s story in one of my talks, I’m always having women sneak up to me afterwards, whispering in my ear that they are juicy tomatoes. Sometimes it turns out they are really lusty women but there are also women with pretty normal drives who find themselves with men who just aren’t interested.

There are low-drive men who’d always prefer a good night’s sleep, men for whom sex never rates very highly. Some men start off with normal drives and then lose interest. There are many good reasons for declining libido in men: medical problems such as vascular and endocrine disorders; chronic illness such as liver disease, anaemia or arthritis; alcoholism and the impact of drugs; grief and depression. Medications can also impact on libido, with anti-depressants a major culprit. Then there are broader issues such as obesity, sleep problems, lack of exercise, body image concerns and relationships problems such as loss of attraction, anger and resentment. Add to this list personal circumstances that can impact on sex drive like job loss, a history of sexual or emotional abuse, conflict about sexual orientation.

Then there’s a small group of men who suffer from testosterone deficiency – a rare problem usually easily treated. There are also many older men who end up avoiding sex rather than risk failure when they run into erection problems. (I’ve included more information about juicy tomatoes and also low drive in men in both my recent books.)

Whatever the reason for a man’s low sex drive, he needs to consider the impact of rejection on his partner. The other day I was giving a talk to a group of older men and told them about a woman who cries herself to sleep because her husband won’t come near her anymore. After everyone had left a man came up to me and clutched my hand. He told him he’d lost interest in sex following hormone treatment for prostate cancer. It had never occurred to him that his wonderfully supportive wife might still be yearning to be touched. He was rushing home to find out, he said with a huge smile on his face.