Opinion: Educate children about good nutrition to eradicate obesity

Improving public health is hard - it takes time to change ingrained risky behaviours. But when there is a powerful, well-funded lobby group with a vested interest in the risky behaviour continuing, change is even more difficult. The history of the tobacco industry is a case in point - there were dirty tricks to keep people smoking. It has taken 50 years of sustained effort from knowing without a shadow of doubt that smoking tobacco is harmful to the complete absence of smoking in public places.

Taking salt in food as another example, even where there isn't a direct commercial interest – salt is cheap and has a low profit margin – it isn't easy to persuade the food industry to invest in alternative flavourings, and the public that they don't actually need all that salt. Here things are on the right track, even if there is more to do, and the evidence is that gradual reductions of salt levels in food have, over time, changed public expectations of taste and reduced salt intake substantially. Sugar is another matter entirely. There is a whole industry producing sugar in its various refined forms – sucrose, glucose, fructose – and the food processing industry has become dependent on these sugars as key ingredients, especially of processed low-fat food and fizzy drinks.