If you gobble down your food and eat until you feel full, then you are three times more likely to get fat compared with people who eat slowly and modestly.

So say Japanese researchers in a study that suggests shifting patterns of behaviour, driven by the advent of fast food and cheap food, are widely to blame for the obesity pandemic.

Osaka University's Hiroyasu Iso and colleagues recruited 1,122 men and 2,165 women aged between 30 and 69 and asked them to closely track their eating habits and body mass index (BMI), a benchmark of obesity.

Around half of the men, and just over half of the women, said they ate until they were full.

Just under half of the men, and a little more than a third of the women, said they ate quickly.

Men and women who ate until full were twice as likely to be overweight compared with counterparts who did not eat until full.

Those who ate both quickly and to satiety were three times likelier to be overweight.

"The combination of the two eating behaviours had a supra-additive effect on being overweight," the team say in their paper, published online Tuesday by the British Medical Journal (BMJ).

The study distinguished between people who ate until full and those who reported binge-eating. Intriguingly, it found those who ate until full had in fact a higher calorie intake than those who gorged.