The book is inspired by the birth of his first child, Sage, one of the dedicatees apart from wife Rebecca, parents Damayanti and Subhash, and brother Suneel. 'For her (Sage), every day, I have started to make smarter choices about the foods I eat and the number of calories I continue,' Dr Gupta confesses in the final chapter. 'I have thrown out some of the supplements I used to take and added more nutritional yet tasty food to my diet. I try to surprise my body every day with new, challenging exercises, always including the all-important upper body training.'

He began writing Chasing Life after Sage was born. His second daughter was born before the book was finished, he told CNN. 'Before becoming a father, I didn't worry much about my own mortality. Now, I want to take better care of myself so I can be there for the milestones in my children's lives. I want to see their graduations and weddings. I want to be there when they have children.'

Much of the book has to do with the eating habits in America but, as readers will find out in no time, it is applicable to people anywhere who cannot resist good food. He says American eating habits remind him of a joke about two people in line at a buffet. The first one complains the food is not good. 'Yes,' says the second one, 'and there's not enough of it.'

'We are eating too much,' he writes, 'and the food we are eating is not good -- at least nutritionally.'

A practicing neurosurgeon, assistant professor at Emory University in Atlanta and columnist for Time magazine, as well as chief medical correspondent for CNN, he says whether he is on television or writing a book, he wants to be completely thorough.

'Television is a huge brushstroke,' Dr Gupta -- who last year won an Emmy Award and four National Headliner Awards (the most any journalist has received) -- said in an interview recently. 'What you gain in reach, you lose in depth. One thing I do to offset that is read medical research all of the time. I take it very seriously. This is ultimately intimate stuff for viewers. If I report (a cholesterol drug) might cause glaucoma, 60 million ears perk up. I want to be 100 percent right.'

But he offers no quick fixes. 'Chasing Life does not contain any gimmicks. There is no single, simple key to a long, healthy life. It is human nature to want an easy solution, but there isn't one. Life is complicated. Chasing Life, the book and CNN documentary, use the latest research as a practical guide for living the longest, healthiest life possible.'

Living a long life has been on people's minds for centuries. Alexander the Great wondered if the Brahmins in India had the secret for a long life. 'Juan Ponce de Leon set out looking for the fountain of youth but wound up discovering Florida, by accident, in 1513,' he muses in the book, which is already on many bestsellers lists. 'Ancient Hebrew and Hindu tales also told of bodies of water capable of conferring eternal life. More than two thousand years ago, Chinese emperors thought there was nothing more important than sending maritime expeditions in search of immortality. They weren't looking for life-giving water but the Isles of the Eastern Sea, where immortals were supposed to live. In ancient Greece, there was a belief that in a remote part of the world lived the Hyperboreans, a people free of all natural ills, with a lifespan of one thousand years.'

In more recent times, he points out, scientists traveled to isolated regions of the Caucasus in what was the Soviet Union, chasing reports of extreme longevity, say 140 years. But longevity as such is not what he is chasing. 'Many researchers of aging prefer to consider what they call health span, not lifespan,' he writes. 'They also use the term 'active life expectancy', meaning the number of years we can expect to live free of chronic functional impairments.'

So, Dr Gupta, who is also a wonderful storyteller and offers one colourful and insightful encounter after another, invites readers on a pursuit: How to stay young even when one is very old. The quality of life is more important, he stresses, than living a very long life.

His book is about the things anyone can do to control one's lives and improve its quality. Taking a hard look at the possible simple changes one can make, he says, 'We are already on the road to practical immortality.' Like an ancient sage, he talks to readers in a reassuring way. 'The goal of this book is to help you extend your active life. There is a lot of conflicting information out there, and I will distill it down for you and show the most effective choices you can make right now to improve your health and longevity.'

'We all make choices every day that affect our lives,' he continues. 'The sum of those decisions equals about 70 percent of the factors determining your life span. That fact alone should empower you to start making some changes that will increase your lifespan and your health span.'

'Also,' he adds, 'many choices you make as a young adult can have long-lasting consequences. Even at 80, it is not too late to chase a longer, healthier life. I will shatter some myths along the way.'

The doctor also questions the myths about many herbal medicines, adding that the belief that one single herbal medicine can take care of one disease is false. He also quotes medical authorities who believe in the need for greater research in the use of supplements.

He questions claims, in different parts of the world, of people living beyond 100 years. The Karakoram mountains of Pakistan and the northern Andes gained reputations as places where people were thought to be extremely long-lived, he notes. 'In all three cases, the tales of remarkable longevity turned out to be more about poor record-keeping than magnificent health,' he notes.

With the publication of his first book, Dr Gupta joins many well-known doctors, including Oprah regular Mehmet Oz, author of the phenomenally successful You: The Owner's Manual. And, compared to the many bestselling books on diet and longevity, Dr Gupta's book reads like a simple manual but his diagnosis and prescriptions look real. 'I am what I preach,' appears to be his motto. It looks like it works too, considering he looks remarkably athletic and energetic despite the many hats he wears each day of the week. Some of his prescriptions include eating less of even a well-balanced diet, having seven to eight hours of regular sleep, and a well-exercised body.

Sounds simple? Find out why Dr Gupta gives more importance to the above prescriptions against much publicised diets for a long life. Eat only until you are 80 percent full, he urges readers. He also recommends -- water-rich food including squashes; less burgers, more lettuce; and a bigger breakfast, so you will eat less the rest of the day.

Though he is critical of certain aspects of supplements and herbal medicine, he has an open mind about its possibilities. He still warns readers who spend millions a year on supplements that most may not work at all. Given his open mind on natural medicine, it is no surprise that some of the strongest backers of alternative medicine have welcomed his book, including Deepak Chopra and Andrew Weil.

Lance Armstrong, a cancer survivor and seven-time Tour de France cycling champion, who has known Dr Gupta for many years, has also given the book his approval, calling it 'probably the closest we'll get to a map to the fountain of youth.'

Dr Gupta, a champion of physical exercise and yoga, also focuses on the Japanese belief that purpose in life, or 'ikigai', boosts health, especially in later years. 'The Japanese don't have a word for 'retire',' he said recently. 'Neither do the Costa Ricans or Sardinians. In Japan, older people are a vital part of society. Research shows that feeling of purpose releases (healthy) endorphins and positively moderates heart rate and blood pressure.'

More important than spending energy and resources in making lives longer, he has said in interviews and appearances in promoting the book, is to improve the quality of life. He bemoans how many elderly people in America live a listless and monotonous life. Americans fail at making elders feel useful or wanted, he adds. 'One way to fix that is for older people to be more functional. That will naturally make them more integrated in American society.'

Photographs: Warner Books