Overweight Scots cut their life expectancy by two months for every extra kilogramme of weight they are carrying according to the latest research.
A major study of the genes that underpin longevity has also found that education leads to a longer life, with almost a year added for each year spent studying beyond school. Other key findings are that people who give up smoking, study for longer and are open to new experiences, might expect to live longer.
Scientists at the University of Edinburgh analysed genetic information from more than 600,000 people alongside records of their parents’ lifespan, including 47,000 Scots. Because people share half of their genetic information with each of their parents, the team were able to calculate the impact of various genes on life expectancy.
Lifestyle choices are influenced to a certain extent by our DNA – genes, for example, have been linked to increased alcohol consumption and addiction. The researchers were therefore able to work out which have the greatest influence on lifespan.
They found that cigarette smoking and traits associated with lung cancer had the greatest impact on shortening lifespan.
For example, smoking a packet of cigarettes per day over a lifetime knocks an average of seven years off life expectancy, they calculated.
But smokers who give up can eventually expect to live as long as somebody who has never smoked.
Body fat and other factors linked to diabetes also have a negative influence on life expectancy.
Professor Linda Bauld, Cancer Research UK’s prevention expert, said being overweight means “dying younger”.
She added: “This large study clearly shows that even after taking into account our genetic make-up and other factors that might affect how long we live, being overweight means dying younger.
“People in this study came from countries on three different continents, but the results provide a clear warning for Scotland, where we have some of the highest rates of obesity in the developed world, as well as the highest in the UK.”
Professor Jim Wilson, of the University of Edinburgh’s Usher Institute, said: “The power of big data and genetics allow us to compare the effect of different behaviours and diseases in terms of months and years of life lost or gained, and to distinguish between mere association and causal effect.”
Data was drawn from 25 separate population studies from Europe, Australia and North America, including the UK Biobank – a major study into the role of genetics and lifestyle in health and disease.
Public health minister Aileen Campbell called on the UK government to ban junk food advertising before the 9pm watershed.
She added: “Tackling obesity is a top priority.
“We continue to engage with the food and drink industry on action to offer healthier choices, including rebalancing promotions and reducing added sugar, to encourage everyone to eat less, eat better and move more.”
The research, published in Nature Communications, was funded by the Medical Research Council.
Shadow health secretary Miles Briggs said: “Scotland’s obesity crisis is a massive public health challenge and this study will add to the pressure on the Scottish Government to set out a range of policies in its forthcoming new obesity strategy that genuinely have a transformative potential to reverse this crisis and promote a healthier diet and lifestyle.”
Labour public health spokesman Colin Smyth said: “This report appears to support Labour’s approach of investing in education and tackling the unacceptable activity gap that exists between the rich and the poor in our country.
“We need to see some credible action to close this gap, or our NHS will simply shoulder an even greater burden for years to come.
“That means stopping the cuts to local budgets and investing in education to give everyone the opportunity to get on in life.
“This research shows a better educated, more active Scotland would be a happier and healthier country – now all we need is a government willing to make the radical choices to make that a reality.”