Smoking (Picture for representation)FAYEZ NURELDINE/AFP/Getty Images

A new research has revealed that every extra two pounds an overweight person carries can cut down his or her life expectancy by two months. Excess weight can shorten life as it raises the risk of coronary artery disease, the study said.

On the other hand, the researchers have found that smoking has the greatest impact on shortening people's lives. In fact, a packet of cigarettes a day can knock off seven years, the research said.

According to Daily Mail, study author Dr Peter Joshi from the University of Edinburgh, said: "Our study has estimated the causal effect of lifestyle choices. We found that, on average, smoking a pack a day reduces lifespan by seven years, whilst losing one kilogram of weight will increase your lifespan by two months."

The study has also revealed that education extends lifespan, every additional year an individual spends in education, their lifespan extends by 11 months by making them aware of the dangers of smoking. It was found that those who continue their education after school live longer.

Co-author professor Naveed Sattar, from Glasgow University, said: "The message is that losing an achievable amount of weight could bring you extra years of life, which is a good incentive."

"We know weight gain cuts people's lives short by increasing their blood pressure, blood fats and diabetes risk, which raises their risk of heart attack and stroke. This study shows we could learn something from the Japanese, one of the thinnest nations in the world [which] has the longest-living people," he further said.

The findings were published in the journal named Nature Communications.