The food industry has come under fire for contributing to the nation's bulging waistline once again, but a new study has challenged the assumption that food is chiefly to blame for obesity.
People have a genetic susceptibility to weight gain, claimed a Cancer Research UK study published this week in The International Journal of Obesity.
Put simply: fat people are getting fatter while thin people are staying slim, said the Weight Gain in the Population report. For some people, decreasing the amount of fatty foods they ate would make very little difference to their weight, it added.
Researchers compared the waist and weight measurements of 12,000 people in 1993/4 to statistics and measurements from the Health Survey for England in 2004.
They found the average weight among overweight or obese people had increased dramatically over the 10-year period, but there had been very little weight change in thin people.
The findings come in the wake of the government's Foresight report, which branded the food and drink industry as one of the major causes of obesity and predicted 60% of men, 50% of women and 25% of children would be obese by 2050.
"Although personal responsibility plays a crucial part in weight gain, human biology is being overwhelmed by the effects of today's 'obesogenic' environment, with its abundance of energy-dense food, motorised transport and sedentary lifestyles," said the report.
In light of the findings, health secretary Alan Johnson pledged to ban or apply more stringent restrictions to the use of trans fats (TFAs) in a bid to tackle the obesity problem.
"I will be asking the FSA to conduct an immediate investigation into the evidence in this area to see if there is anything more we should be asking the industry to do," said Johnson.
Johnson's comments were "clouding the issue", said Julian Hunt, director of communications at the FDF. "This is completely bizarre," he said. "Scientific evidence supports the view that TFAs do not cause or exacerbate obesity."
He added that the industry had already made significant headway removing TFAs from products.