My father could never follow his doctors' instructions to put on weight - and obviously I inherited the same tendency. So there is no doubt in my mind that our genes influence our weight. I don't know much about it, but I assume there's a fairly normal distribution of this. A few of us are relatively immune to food - and at the other end are those who have genetic issues leading to weight gains. In hindsight (one of the few benefits of being older) my scepticism about "genetic weight gain" was largely due to the large numbers of people claiming to be subject to it.

Unless the distribution is skewed (as opposed to normal), most of the claims to suffer because of your genes appear to be more of an excuse than reality. Of course any individual claim has to be taken on it's own merits - but the trend is fairly clear.

The bigger picture was brought home when Dr Robyn Toomath, a long time obesity fighter, resigned from the body she formed because in 15 years she felt it had not achieved anything. The 60 Minutes item showed a Minister of Health acting much as his forebears used to do with issues like tobacco. He made some valid points - it is primarily a matter of private responsibility. And clearly those who know their facts and have self-control can indeed make sensible decisions. But the fact is that our status as an obese nation isn't natural.

Back in the "old days" most people fell into a mid-weight range - but as the weight has gone up, so has the food industry pushed food with higher levels of added sugar, salt and fat. In fact the combination of added these in combination is itself fairly new.

Now the fact that the two have risen in parallel does not in itself prove a causal link. But the reaction of the Minister and food industry generals is almost obscene. This is a problem, with substantial real costs, and nothing except talking is happening.

Some have suggested removing GST from fruit and vegetables but as an accountant one of the things that's really great about our GST system is it's simplicity. Just compare it with Australian GST and see the differences. The main problem with GST is it's regressive nature - and every increase hits the poor disproportionately. Despite that it does do things - like get something from even those whose money comes via the black market. But it has to be kept simple - there are already people looking for ways around it.

So if that's not a starter, what about a sugar tax? While it would raise the price of some basic products, it would raise the price of some of the main culprits. Or we could follow the example of Britain by starting with sugary drinks. But doing nothing is a social and financial cost we cannot afford.