As we step into a brave new year, the Food Militant Tendency is out in force.

First we hear that Westminster Council is considering reducing the benefits it pays to local residents if they fail to heed doctors’ orders to take more exercise. Even doctors apparently think it’s a daft idea. Others may see yet another example of creeping authoritarianism.

Not to be out-flanked, Labour is proposing to introduce legal limits on the fat, sugar and salt content of all prepared foods. This panacea has been wheeled out on several occasions over the past 10 years, usually by zealots who invariably greet any government initiative with an invocation to go “further and faster”.

“Even doctors apparently think cutting benefits is a daft idea”

Labour ministers considered it and rejected it, if only because of its total impracticability. But then the militant believers in any cause are seldom detained by the boring details of implementation. As Peter Ustinov observed: “The primary function of a priest is to keep his congregation awake”.

Is there really an obesity epidemic in the UK? The Social Issues Research Centre in Oxford argued in 2005 that the 2003 Health Survey for England overstated the scale of the problem, especially in children. The figure quoted for the UK was 15.5%, compared with the less arbitrary international measurement, which considers both weight and height, of 6.75%.

The 2012 Health Survey, however, reported that 30% of children aged 2-15 years were “overweight or obese”. Shock, horror - it’s doubled in only nine years! But since the proportion of “overweight” people in any age group is usually much bigger than that of the “obese”, a tighter definition would have produced a less alarmist result.

According to the Department of Health, “recently reported modelling suggests that without action, 41-48% of men and 35-43% of women “could be obese” by 2030. Computer modelling, or mechanical extrapolation of current trends based on debatable definitions, is no basis for policy.

One sane voice in the government, a Liberal Democrat minister, no less, has suggested that the sensible way of losing weight would be to follow a balanced diet and getting a bit more exercise. Glory, Hallelujah!