Genes, yes, but obesity pandemic mostly down to diet：study 研究：基因有影響，但肥胖流行病主因在飲食
A three-fold jump since 1975 in the percentage of adults worldwide who are obese has been driven mainly by a shift in diet and lack of exercise, but genes do play a role as well, according a large-scale study published Thursday.
For people genetically predisposed to a wider girth, these unhealthy lifestyles compounded the problem, resulting in an even higher rate of weight gain, researchers reported in The BMJ, a peer-reviewed medical journal.
To tease out the relative impact of environment and genes on obesity, scientists led by Maria Brandkvist at the Norwegian University of Science and Technology combed through data on nearly 120,000 people in Norway whose height and weight were regularly measured between 1963 and 2008.
Adults began tipping the scales at significantly higher weights in the 1980s and 1990s, they found. Those born after 1970 were far more likely to have a substantially higher BMI as young adults than earlier generations. （AFP）