Greater quantities of food available in supermarkets and eateries is subconsciously driving people around the world to eat more and gain weight, New Zealand researchers said Wednesday.
A study by the University of Auckland School of Population Health analyzed increases in food supply and obesity in 69 countries and found both body weight and food supply had risen in 56 countries from 1971 to 2010.
In 45 countries, which were mostly high income countries like New Zealand, the increase in food energy supply was more than enough to explain the increases in body weight, lead author Stefanie Vandevijere said.
"Our study shows that oversupply of available calories is a likely driver of overconsumption of those calories and can readily explain the weight gain seen in most countries," said Vandevijvere.
"Overeating to gain weight is not usually a conscious individual decision and many things in the food environment influence our diet. One of these is likely to be the sheer quantity of palatable food that is available in the food supply," she said.
"It creates a kind of 'push effect' on our diet and we tend to subconsciously overeat on the calories and gain weight."
The study provided more evidence that governments needed to develop the right policies to reduce obesity, which was a risk factor for many health problems, including diabetes, heart disease, stroke and some cancers, she said.
The World Health Organization's 194 members agreed on a Global Action Plan for the Prevention and Control of Noncommunicable Diseases at the World Health Assembly in May 2013.
One of the plan's nine voluntary targets was to "halt the rise in diabetes and obesity."
It also proposed measures that countries could take to tackle obesity, including restriction of the marketing of unhealthy foods to children and pricing strategies such as taxes on unhealthy foods.
Between 1980 and 2013, the proportion of adults globally who were overweight those with a body mass index of 25 or more was up from 28.8 percent to 36.9 percent in men, and from 29.8 percent to 38 percent in women.
