Hurray for Tom Watson. The Labour deputy leader’s story about how he has reversed his Type 2 diabetes by shedding seven stone is fantastic. It’s great for Watson personally but is also inspiring for the nearly five million people in the UK suffering from this crippling disease.

The 51-year-old Labour MP set about losing weight after being diagnosed with Type 2 diabetes. He was 22 stone. He lost the weight by going on what’s known as the Keto diet – high in fats – and by cutting out all sugar, processed foods and starchy carbs.

At the same time, Watson exercised. Slowing at first, by walking everywhere, and then more vigorously by cycling, running, boxing and weight-training. Just a year later, he’s off medication for his diabetes, and is in remission.

More pertinently, if not inadvertently, Watson is perhaps the first Labour politician to ever admit the nation’s health can be improved without the NHS having to spend more money. What Watson has shown, with his terrific discipline and self-motivation, is that changing lifestyle behaviour can be achieved without running up huge NHS bills, banning ‘two for one pizzas’ or introducing ’sugar taxes.’ He has said it himself by telling fellow sufferers in his numerous interviews, that they too can be cured of Type 2 diabetics by losing weight.  As he puts it: “Yes, we can.”

And if Simon Stevens, chief executive of NHS England, were smart, he would be signing Watson up for a series of those ‘Before and After’ Daily Mail style pictures to plaster on NHS billboards up and down the country.

It’s such a fabulous example of what can be achieved through motivation that everyone should see the transformation: the pictures of him at 22 stone and today are remarkable.

Yet  the tragedy is that many of those with Type 2 diabetes do not know that they too can cure themselves, that the condition is reversible with weight loss alone. That lack of awareness is partly because of the way the GP and NHS hospital process works, as doctors and consultants have until recently tended to prescribe medicines rather than go to the root of the obesity problem and give patients nutritional advice.

But it’s also a lack of awareness on the part of the patients. One of the world’s leading specialists in diabetes, Professor Mike Trenell, says that’s changing. “There has been a paradigm shift in the way the medical profession is treating Type 2 diabetes. It used to be seen as a chronic disease but now we know that in the majority of cases it is reversible with weight loss.” For patients who have suffered from Type 2 more than five years, treatment by diet is more difficult because in many cases the pancreas has been damaged.

Professor Trenell, head of metabolism and lifestyle medicine at Newcastle University, says that it is now proven that too much fat stored in the muscles, liver and pancreas leads to Type 2 diabetes. The reason is not that the person is eating too much sugar per se, but that as a result of the increase in fat, there is not enough space left in the muscles or pancreas to store the sugar you need. So the pancreas does not respond properly.

Losing weight – however you do it – is the answer. And it’s the only serious solution to Britain’s obesity crisis and to stop Type 2 becoming an epidemic. The latest UN study showed that we are the third fattest country in the world after Turkey and Malta.

Here are the facts: around 14 million UK adults are obese and another 15 million more are overweight. That means nearly half the entire UK population is, and there is no polite way of putting it, simply fat. A third of all children are leaving primary school obese. And, if these trends continue, half of all children will be obese by 2020.

This is a catastrophe, and one which has crept up on us quietly. Only thirty years ago, in 1998, just 3% of adults in England had diabetes diagnosed. By 2016, that number had doubled with 7% diagnosed with the illness.

Type 2 diabetes is expensive to cure and is a killer: 24,000 people are estimated to die each year prematurely because of the disease while the side-effects are pernicious leading to kidney failure and dementia. Something like 120 feet and toes are being amputated from diabetics every week in the NHS.

Treating the illness costs the NHS 10% of its annual budget, that’s about £12bn per annum being spent on something that could be treated with better nutritional guidance and a dose of Watson’s drive to prevent the next generation being as obese as their parents. It’s also money that could be saved and used for other more life-threatening illnesses were there is no cure.

How can that be achieved? Professor Trenell, who has helped thousands of people to lose weight and reverse their diabetes through his work, does not believe it is the work of the NHS, or indeed government, to solve.

It’s only when society and communities acknowledge the problem, he claims, that changing behaviours will come about. “The sugar tax was good in that it made the drinks company think about how much sugar they were putting into their drinks. But it does not stop overweight people from drinking or eating more at all. ”

He calls it the ‘muffin logic’. “One muffin contains 300 calories and will take 40 minutes of running to work off. Who is going to read that on the side of the packet before they eat the muffin? Telling people the number of calories doesn’t work either. We need to empower them to understand what they are doing to their bodies.”

There’s another thing that people don’t like to talk about enough. Obesity is a problem that affects the poorest in society more than the wealthiest. Take a look at the poorest parts of our big cities and its where you find the most fast food outlets, and the biggest clusters of obese people.

Watson’s story will encourage many of those with Type 2 diabetes to change their lifestyle too.

Where he is wrong is to say that when Labour comes to power he will call for a cross-party commission to investigate the problem. Well, that’s too late and a Labour government is not going to happen anytime soon anyway. Someone once said the personal is political. Far better for Watson to keep telling his heroic story.