In a study published in the journal Nature Clinical Practice Endocrinology and Metabolism, scientists have attributed hormonal imbalances caused by high calorie, low fat western diet to be responsible for the obesity.
Robert Lustig, a Pediatrician at the Children's Hospital of the University of California in San Francisco, said: "Our current western food environment has become highly insulinogenic, as demonstrated by its increased energy density, high-fat content, high glycemic index, increased fructose composition, decreased fiber, and decreased dairy content."
He said the changes in the food manufacturing process, where in sugars are now added to foods that never used to contain sugar and fibers being removed, have made the food toxic and addictive leading to obesity. He has pointed out that this upsets the balance of two hormones leptin and insulin, which regulate how much we eat. High-sugar, low-fiber diet causes leptin to be suppressed by the effects of insulin leading to decreased activity and increased appetite.
He said children could not be blamed or expected to take personal responsibility for their diets when they were offered cheaply prepared fast foods full of sugar and devoid of fiber.
Caroline Swain, executive director of the charity Weight Concern said, "It is clear that if you give a child the option of eating fatty, sugary foods then they will choose it. Parents and schools need to offer proper healthy choices, not just the stark choice between a bun and a carrot."
Food and Drink Federation spokeswoman said: "The industry has recognized that it has a part to play in combating obesity. What we need to look at, and we need to help people look at, is the whole diet. There is not one single food that is bad for you. It is about encouraging people to have a balanced diet to suit their needs."