Paul McKenna: Self-help guru who has aided millions and eased my craving for chocolate

Of course I wring my hands about this unhealthy, waist-blowing habit – so no, I don't need a lecture. I'm 'fessing up to the weakness simply because I am possibly a project ripe for the help of Paul McKenna, the man whose books have titles such as I Can Make You Slim, I Can Make You Rich, Quit Smoking, Change Your Life in 7 Days and Instant Confidence, and have tapped into the zeitgeist of self-loathing so successfully that they have sold 17m worth in the UK alone. We have an appointment to meet.

He has devoted fans the world over. Enter the office on the ground floor of his smart Kensington mews house, and you'll be confronted not only by a preview cardboard cut-out version of the man himself but also stacks of his books translated into many languages. Paul and his "mental reprogramming system" seem to be taking hold particularly strongly in Eastern Europe at the moment, says his assistant Kate.

He bounds into the room in sharp grey pin-striped suit and crisp open-neck shirt, trademark specs and a large gold watch you'd call...erm, some kind of statement...perhaps one about how expensive his time is? His skin looks buffed and the gaze is as intense as you would expect. (It's important to drink in every detail, not just for professional reasons. McKenna provokes the kind of curiosity which means that even those who profess to think his books are garbage – yet usually have not read them – will quiz you in ridiculous detail later.)

Before we can retire to his shi-shi private quarters – decked in dark shades relieved by the odd oriental ornament, little personality evident save for the photos of dogs he presumably keeps in his main home in Los Angeles – he has to check on sales of his new book I Can Make You Happy. "It's part of my compulsive, competitive nature, I suppose", he says, pleased that he's now top of the Amazon non-fiction chart. McKenna's works are a bit like those dogs – not just for Christmas. He says he wants to help those who spend the whole year beating themselves up and wishing they could change their life.

Now 47, he grew up in Enfield, north London, his father a builder and mother a cookery teacher. He left school with few qualifications but later got a PhD in neuroscience. By the age of seven he knew he'd be famous. "I thought I'd be a pop star, probably..." His involvement with music started as a DJ for Radio Top Shop and took him to Radio 1. He had become interested in hypnotism and was even beginning to perform, egged into it partly by people at parties asking him to make so-and-so bark like a dog or hop like a kangaroo. By the early 1990s he was attracting audiences of 12 million for The Hypnotic World of Paul McKenna on ITV.

I expect him to purr into my ear, but he's perfectly straight; not repetitive and persuasive as such, just fast-talking and seemingly keen to answer any question, even the one about whether he has used his powers on women. "For a while I used to date dysfunctional women, so I'd feel better about myself by helping them". He says he once made a girl like curry because he did. The conversation grazes across his mother's strong character and comes to rest on what makes him get up in the morning. "Purpose. It's the cornerstone of good mental health. Having a purpose is largely about feeling happy and life having some meaning. If you don't have that, then you're in a bad place, and depressed people tend to lack that sense of purpose".

In preparation for writing the book he spent months with depressed people and says he became pretty low himself. Stepping into someone else's situation and trying to experience whatever is bothering them is part of his technique, but it did take him a while to recover, initially with the help of his own know-how and later by "seeing someone". He admits that depressed people often loathe self-help books, though. "You can't get through depression, so you have to go round it. What I'm hoping for (with them) is word of mouth, and there will probably be a few who'll read it so that they can attempt to prove me wrong. They'll discover that I'm not glibly trying to cheer them up but offering ways of building a bridge out of feeling so bad. Of course anyone who's clinically depressed should see their doctor. The book is also aimed at people who have those vague feelings of 'is this all there is?' and others who are happy but think they could be happier. It's not about being 'up' all the time but having an emotional range, still feeling sad when someone dies or someone makes you feel justifiably angry."

Reading McKenna's books, you're struck by the simplicity of the messages and the methods. His tips on eating badly boil down to: eat when hungry, eat what you want, not what you think you should; eat consciously and enjoy it; chew everything slowly 12 times and stop when you are full. He abhors the diet industry for "making people fatter", and he gets my vote for that. He explains briefly the scientific research of others that underpins his advice, but says readers just want to be told what to do. The methods McKenna has adopted include NLP – Neuro Linguistic Programming – involving all sorts of techniques such as tapping of acupressure points to help reinforce the positive.

Paul McKenna went into self-help in a big way after a court case in which a man he'd made dance like a ballerina in his stage show later claimed the experience had led to him suffering schizophrenia. This could have ended his career but the cavalry came in the shape of a host of medical specialists, who were appalled at the ignorance displayed about the biological and genetic factors involved in the condition. Living in LA, "a town full of ruthless over-achievers", suits him very well, he says.

In our last few minutes together he gets me to close my eyes and imagine a mouthful of chocolate mixed with tripe, hair from a barber's floor and spittle. He relentlessly repeats the description. My desire unsurprisingly falls off in the face of the onslaught. He talks increasingly rapidly, his voice getting more urgent, and I can feel involuntary expressions of repulsion on my face. He then replaces awfulness and tells me to fix in my mind the feelings and images of three times when I've been very happy while also pressing my right thumb and index finger together. Over and over, he urges me to think happy, and when he brings me out of this state of – what? – he says when I want chocolate I will think of the awfulness but can use the finger pulsing and happy thoughts to summon the same endorphin rush I would have got from the chocolate.

And the results? It's now 4.55pm, and I haven't felt that familiar urge. Whether this is merely a temporary desire to please Paul or a real change remains to be seen...

I Can Make You Happy by Paul McKenna is published by Bantam Press, 10.99. To order from the Yorkshire Post Bookshop: 0800 0153232, www.yorkshirepostbookshop.co.uk

Happiness is a habit change

Paul McKenna is an admirer of the work of "happiness psychologist" Dr Robert Holden, who ran an experiment to show how we can alter happiness levels by changing habits.

He set about replacing old habits with new ones, and the BBC made a documentary on the study, which involved following a group of depressed people for several weeks after first doing an MRI scan on each of them to look at activity in the area of the brain corresponding to happy thoughts and feelings.

The scan showed they had signs associated with depression. Holden prescribed three simple steps: smile or laugh for at least 20 minutes a day; take at least 20 minutes' exercise a day and place coloured dots around every room at home and at work. Every time they saw a dot they had to think about a positive memory or possibility.

After a month all subjects said they felt happier, and a scan showed they had significantly increased activity in the relevant area of their brain. Six months later the benefits had not changed.