Last week, Boris Johnson blamed his being overweight for the seriousness of his case of Covid-19. And the links between the coronavirus and obesity are compelling – the obese are twice as likely to need hospital treatment for the virus and a quarter of all fatalities had diabetes.

Also of note is the higher incidence of corona-related death among those groups that had a higher incidence of obesity in 2018/19 – men (67% obese), those aged between 45 and 75 (78%), and those of African or afro-Caribbean heritage (73%).

To say that we have an obesity problem in this country is an understatement. It is one of the major issues of our time. Over 70% of Brits are overweight or obese, 1 in 5 children is obese before they get to secondary school and we spend more on obesity-related health problems than we do on the police, fire service and judiciary combined.

The number of obese people in the UK has nearly doubled in the last 25 years. Government after government has tried to tackle it with little success. But, oddly enough, it is one of the few things brings both sides of the house together.

So it should come as no surprise that the prime minister’s latest scheme – a war on obesity – was welcomed by the Labour leadership. As a former(ish) fattie myself – I was a hefty 142kg last year and am now a still cumbersome 101kg – I would love to see it work. But policy has always seemed more PR than anything else.

The number of obese people in the UK has nearly doubled in the last 25 years.

Take two recent examples – George Osborne’s sugar tax (2016) and Sadiq Khan’s ban on junk food ads at bus stops and tube stations (2018).

Both have more than a hint of social justice about them. The blame is laid at the door of the companies who sell the goods, not the consumers who buy them. More on this in a moment. Just a quick side note on the ineffectiveness of these policies.

Though it was praised as a success – by, err, George Osborne – the sugar tax achieved very little. Sugar giants did cut the amount of sugar in their drinks (by 28.8%), but it didn’t stop an overall rise in sugar consumption, neither did it get obesity figures down. Funny how easy success is if standards don’t apply.

But turning the screws on Coca Cola and Pepsi looked good. Unethical companies brought to justice and all that but it didn’t do them much harm. Their prices went up and their package-sizes went down. Consumers picked up the cost with no health benefit to themselves. A tax isn’t the best form of defence against obesity.

Mayor Khan’s policy also targeted companies, their visibility rather than their profits. Junk food might be less obvious to the public but removing ads for Big Macs doesn’t kill the craving, worst of all it doesn’t change the convenience or cheapness of fast food.

They make for good soundbites not smaller waistlines.

To look at it less cynically, these policies get the green light because they resemble what killed off smoking. Smoking adverts were banned, branding was cut and cigarettes are very heavily taxed.

But smoking is more directly linked with death which adds a moral dimension. If you smoke, you are not only putting your own life at risk but the lives of others also. Because genetics, and certain medical conditions – particularly mental health ones – can cause obesity, the government cannot take the risk of seeming to villainise the obese as they were able to with smokers.

Without the fear of health risks and death, no government will be able to muster the moral force to make this approach work – nor should they.

Sadly, the fear matters. Something that Tom Watson makes clear. In Downsizing – his book about weight loss – he explained how the thought of an early death and leaving his children fatherless pushed him to action.

It’s difficult to pinpoint the exact moment when I started to lose weight but what I know is that it happened after I came to the same realisation – that actions had consequences.

After that, I could see – faster than I would have liked – that what I was doing to myself wasn’t just effecting me, it was effecting everything around me. I was constantly knackered, dog-tired over the smallest things: making a meal, stairs, even making my bed. At the end of the day, I’d slump into bed probably clothes on for the long nap, only to roll out of it a few hours later feeling totally unrefreshed.

The weight loss itself is comparatively straightforward compared to the epiphany. The realisation is the structure – the discipline – for the goal that is weight loss. When you have that you can see the catalogue of behaviours that keeps you locked in place. Going to bed on a full stomach, not cooking your own meals, or wolfing down your food, rather than enjoying it.

Not much is known of Boris’s plan. He is obsessed by the idea of getting people to walk or cycle to work – incidental activity.

On paper, it’s promising. It’s how I shed the pounds. I used to bus and tube everywhere. But when I started walking before work I started to feel better, energised. Now I walk the 4.5 miles home from work every other day – when I’m not furloughed that is.

The PM’s plan ain’t bad, but he can only lead us to water. He can’t make us drink.