Hugh Byrne is an NHS hospital consultant in London. Lucy Mowatt is an NHS dietician.

As Conservatives, we rely on our own strong sense of personal accountability. But not all of the population have such resolve, and big-government interventions are often suggested to encourage the healthier lifestyles that will be less of a drain on the NHS.

How to balance the health of the public with the choice of the individual is difficult when we are the opposite of a nanny state government, as Paul Goodman pointed out on this site a week ago.

Direct and punitive taxation is not our style, and it is disappointing to see how some of our MP’s such as Dr. Sarah Wollaston (chair of the Commons Heath Committee) are calling for a knee-jerk sugar tax.

A better and more sensible approach has been taken by Jane Ellison, our public health minister, who has managed to effect key changes by working constructively with our industry partners and other stakeholders without upsetting the public.

These changes include significant reductions in salt, sugar and alcohol content that have not bothered the electorate at either the tills or the table; and whose benefits will be reaped in the longer term. Any direct lifestyle interventions that Jane has introduced have been those with broad public support, such as the ban on smoking in cars carrying children.

As she rightly points out, it was public pressure that caused the large supermarket chains to remove sweets from their checkouts, and not the government.

The McKinsey analysis proves that this current conservative approach, whereby the unconscious factors involved in unhealthy consumption are tackled, is the most productive. This is why further practical changes are planned in terms of reformulation, portion size and advertising, including product placement.

Our Conservative government can bring these about by negotiation and not regressive taxation and alienation. Salt consumption has come down by 15 per cent already and there is no reason why sugar, which is already taxed through VAT, can’t follow. Any revenue from such an unpalatable levy as a special tax would be a mere drop in the ocean of the entire NHS budge in any event.

Wartime rationing apart, it was Gladstone who last faced such a major public interest in sugar taxation – but back then that populist move was to abolish the tax as global transport made the commodity cheaper.

This did not cause the subsequent increase sugar consumption that the epidemiology would suggest: instead it was the developments that were already happening in industry that made mass production and consumption easier.

In this current debate parallels are being drawn between sugar and other vices, such as tobacco and alcohol, but there are differences between their availability, as well as their psychology: habit is not addiction and need is not want.

While a tax on sugar is unlikely to cause black market trading and product adulteration, it would only ever penalise those in the poorer socio-economic sections of society. A sugar tax won’t help them – and it’s simply not us.

If demonising the white stuff and going against the Conservative grain of low taxation is not the silver bullet for improving the health of the nation (and Public Health England’s Sugar report stated that the training of non-nutritionists is “an area that requires development…”) it’s odd therefore that Jamie Oliver – a celebrity chef and media personality with no formal training in nutritional epidemiology – should have been afforded his own session to discuss with Dr Sarah Wollaston MP and her Health Select Committee his dietary factoids and personal opinion on sugar.

Dr Wollaston and her committee appeared in thrall to every sound bite: there was relatively little ‘grilling’, and no questions as to what made him an expert bar his media profile and a his attempt to improve school meals.

Like media cardiologist Dr. Aseem Malhotra and the ‘Action on Sugar’ brigade, the mainstay of Jamie’s proposed tax has a “very basic hypothecating of nutrition” (sic). By opining that it’s “all down to sugar, isn’t it?” they clearly illustrate their collective lack of scientific evidence.

The fact that obesity levels have continued to march inexorably upwards – despite falling sugar consumption over two decades – is ignored.

Such a lack of reasoned debate was also sadly evident at the recent All Party Parliamentary Group on Diabetes.

When chairman Keith Vaz MP purported that an unsubstantiated link between sugar intake and his type-2 diabetes was proof that a sugar tax is needed, MPs present across the political divide were unanimous in their overwhelming support for his proposals, and clamoured to be photographed with a celebrity chef for their constituency newsletters.

The public deserve better than this. No one can deny that the calories from sugar contribute to the excess energy intake associated with weight gain, but as the experts know, it is an overly simplistic viewpoint to point the finger at a single nutrient when it should be a ‘whole diet approach’ such as the Mediterranean-style diet that is advocated.

A tax stick would no doubt reduce consumption of sweetened drinks, but there is simply no evidence that taxation can influence obesity in the UK population.

Public Health England give three more ways that they would consider more effective than a simple sugar tax: limiting price promotions, limiting advertising to children, and reducing the sugar content and portion size of everyday foods – all of which Jane Ellison is already working toward.

The promotion of exercise and activity in the population is, of course, is the other difficult side to this large coin.

We wholly support David Cameron’s veto of the sugar tax, and he should not bow to public pressure on this punitive measure which will only serve to make the poor poorer without any proof that it will improve our country’s collective obesity.

The Conservative priority must instead be to ensure health policy is guided by experts in the field of nutrition – and not enthusiastic amateurs spouting sound bites instead of science.