Breathe in deeply through your nose and then let the breath out through your mouth. Become aware of your breath. Is it coming from your abdomen, your diaphragm or your chest? Is it slow or fast? Shallow or deep? Just observe the way you breathe, and what happens to your body.”

I’m having my first meditation session, instructed by one of the most influential men you’ve never heard of, Andy Puddicombe, a former Buddhist monk who is now a meditation teacher and the “go-to guru” for Cabinet ministers, corporate big-wigs, Premier League footballers, leading actors, musicians and famous shrinks.

But the friendly, shaven-headed man sitting next to me is not your standard celebrity healer. Puddicombe, 37, was a tennis coach and personal trainer from the ages of 18 to 21, went to university to do sports science, then dropped out to study meditation and train as a monk. He grew up near Bristol but now lives in Islington, North London. He’s open, likeable, direct, the kind of man my mother would approvingly call “down to earth”. He glows with health and energy and has an aura of natural calm. He also has two characteristics that distinguish him from most self-styled gurus: he is unaffected and modest, and he is eminently qualified to teach his subject.

As an ordained monk, Puddicombe spent ten years in monasteries in Nepal, India, Tibet and Russia, often meditating for up to 18 hours a day. He left the monastic life to teach meditation and to fulfil what he believes is his vocation, “to bring meditation [or ‘mindfulness’, as it’s often called] to as many people as possible, and especially to people who wouldn’t usually consider it”.

His timing couldn’t be better. The Beatles were the first to popularise meditation in the UK in the Sixties, but it’s only now that it has reached its tipping point. A growing body of respected research over the past 20 years has suggested that meditation improves a range of psychological and biological functions, including blood pressure, sleep patterns, stress control and levels of serotonin, the happy hormone. The evidence is now so overwhelming that in 2007 it was approved for use in the NHS and independent healthcare — many of Puddicombe’s private clients come to him through GP referral, and he uses it to help with anything from depression and eating disorders to addictions.

The concept of meditation chimes with the times, too. Cheap, portable and scientifically proven to be a powerful defence against stress and anxiety, it’s the perfect self-help treatment for the current convergence of tough times and postconsumerist values.

When I ask about the famous clients, he politely brushes the question away, partly to protect their privacy, and because their celebrity seems genuinely unimportant to him. “One great thing you learn through practising meditation is empathy. You understand how much the same we all are.” He is just as focused on his non-celebrity clients, and has started a new not-for-profit project called Headspace, which aims to make meditation “accessible and practical”, meaning free from mystery, jargon and religion. It will feature group-training events and interactive online resources including podcasts and MP3 downloads. “My aim is to get as many people as possible to try it for ten minutes a day and see that it’s a great practical tool for everyday life.” He has started a regular Friday morning slot on the BBC Radio 2 Chris Evans Breakfast Show, and is working with Jamie Oliver’s website on issues surrounding “mindfulness” around food and eating.

Anyone can learn to meditate, Puddicombe says. “Meditation is about putting you in the present moment. It’s not about being caught up in never-ending cycle of thoughts that seems to occupy our every waking day. When you step out of that, it brings a sense of profound relaxation, and lets you experience any activity — from your work to eating a sandwich — more directly and more intimately.” Meditation has two main effects on the mind, “calm and clarity”. Finding calm is often what brings people to meditation, “but the greater, long-term benefit is clarity. It gradually allows you to still your mind; you understand what is really causing you stress and become more self-aware”. Most of us don’t know ourselves very well. “We think we do, but we can’t. Our minds are like a pool of water. We’re constantly dropping thoughts into them, which ripple the surface. Meditation doesn’t empty your mind but it creates space between the thoughts so the surface can be calm and we can see our reflection more clearly.” Many people find it helps to give them direction and makes them more focused and creative.

Puddicombe is a great debunker. He teaches meditation to people wearing ordinary clothes, sitting in chairs: “There’s no need to sit in a special posture on the floor.” Ideally, he says, the practice should be integrated into our everyday lives. “You can meditate on the Tube — it’s a good way to beat commuter stress — and there are techniques you can learn so you can meditate while you are brushing your teeth, at your desk or walking home. I recommend three short sessions of ten minutes a time, rather than one big session in the morning.”

To show me how it works, he takes me though a short training session. I sit on a chair with my back straight but relaxed, my feet on the floor and my hands resting on my stomach. He tells me to close my eyes and focus on my breath. The first step is becoming aware of it, and then to count each breath as it comes and goes up to ten, and then to start again. To begin with I’m thinking of other things at the same time — did I send off my car insurance ? — but then, for a few moments, I’m not thinking about anything except noticing my breathing, which has gradually become slower and deeper. I have to “re-enter” the conversation slowly — it feels as if I’ve been in a different room, and for longer than ten minutes. If I can feel noticeably different after ten minutes in a strange office with someone I’ve just met, what could daily practice do for me?

“The word ‘meditation’ comes from a Sanskrit word that means ‘mind training’. It gives you deeper insights and deeper peace. It changes all your perceptions, about yourself and others. Then you take what meditation gives you into your work, and into your relationships and communications with other people.

It makes them all better and it makes you happier.”

If you would like to learn how to meditate, Andy Puddicombe from Headspace is holding a series of One-day meditation events that take place in London on 15 May, 12 June, 24 July and 18 September, costing £249. To find out more or book a place visit www.getsomeheadspace.com