NEW YORK: Small changes in lifestyle including healthy diet, moderate exercise and socialising could keep you young and healthy, according to a new book that outlines how we can improve the quality of life as we age.

The book "The Science of Staying Young" by John Morley, director of the division of geriatric medicine at Saint Louis University in the US, outlines a 10-step programme to improve the quality of life as people age.

The book advises people to eat a nutritious and balanced diet with plenty of fruits and vegetables, enough proteins and lots of fibre to keep organs running smoothly, reported the online edition Medical News Today.

"Thriving at any age and feeling younger and more energetic is as much about diet as it is about adequate medical interventions and adequate exercise," Morley said.

He said people must find ways to add physical activity into their lives. In addition to moving around more by vacuuming, raking the leaves or walking the dog, the book advises people to exercise for half an hour every day.

Morley recommends taking vitamin D because it helps the body absorb calcium, which strengthens bones. He added that moderate, weight bearing exercises such as regular walking help in bone strengthening.

He recommends exercising the brain to keep it sharp by tackling a Sudoku puzzle, playing video games and working on mental mathematics problems.

"The goal of brain fitness is to prevent certain mental abilities from slowing down or reverse such changes if they have already taken place," Morley said.

He also advises against smoking after the age of 60.