Take Jamie Oliver out of the equation and a sugar tax, or at least a vast reduction in sugar intake is urgently needed.
Everybody should look at the correlation between national obesity and the amount of carbs consumed to be in no doubt of the driving force behind this pandemic.
The human body requires no carbs whatsoever to be ingested externally. The small amount of glucose required by the brain is easily synthesized by the liver.
If your diet is carb centric, which is true for most, you will find it almost impossible to lose actual fat (not water bound with glycogen) as your body never adapts to fat burning.
The incidence of the introduction of industrial quantities of carbs being consumed in the last few generations is way, way, way too soon for evolution to adapt to healthy carb burning.
We have been designed to process fats and protein efficiently, but we are deliberately short circuiting this mechanism.
Governments and the food industry are undoubtedly largely responsible for food supply, but there is no reason why, especially parents, cannot ensure that their children do not end up obese.
Study after study shows that obese and morbidly obese people have very little chance of ever returning to a sustainable, healthy weight without drastic intervention and even then many manage to put weight on.