The obesity crisis, the record 2.8 million working-age Britons too sick to do so and the rising prevalence of mental illness are sobering reminders that the UK population’s health is not good.

But even for those familiar with this troubling situation, the Health Foundation’s analysis of the latest Office for National Statistics figures on healthy life expectancy sheds uncomfortable new light on the country’s poor and deteriorating health.

The government is trying to rescue the NHS from an ever-rising demand for care, to grapple with public finances hamstrung in part by lost tax revenue from those unable to earn, and to pursue its key goal of economic growth. For Downing Street, the thinktank’s findings should be quietly terrifying.

Healthy life expectancy captures how long people live in good health, free of illness or disability. As the Health Foundation says, it is a metric that gives a more comprehensive picture of the nation’s health than life expectancy, which only measures how long people live for.

The measure involves quality, not just length, of life. The longer someone enjoys a life free of pain, surgery, medical attention and regular medication, the better their life.

Internationally, among other rich countries, healthy life expectancy is rising, albeit modestly – by four-tenths of a year over the last decade, the Health Foundation found.

But it is a different picture in the UK. Between 2012-14 and 2022-24 it fell by two years across the population as a whole. It now stands at 60.7 years for men and 60.9 years for women.

“In 2022-24, healthy life expectancy in most areas was below the current state pension age of 66 years,” the thinktank says. “This means that in most places, people on average spend some years in ill-health before reaching retirement.”

In the poorest areas it is less than 55 years, “indicating that many people in these areas are entering ill-health during their working age”.

This is all a shock but not a surprise. These findings tally with existing evidence about the UK’s health being in decline, especially among working-age adults. Despite that, the foundation adds, successive governments have done too little to respond. The consequences are dire: “a growing economic and fiscal impact as well as a substantial human cost”.

The UK’s two-year fall in healthy life expectancy means it is “diverging from trends seen in most comparable high-income countries”. The huge toll of avoidable illness related to people’s lifestyles helps explain that difference. For example, 40% of cancers are preventable and are linked to bad diet and alcohol, as well as smoking. Experts scoff at the government claim that it is already “radical” in its approach to deep-seated public health problems such as obesity and drinking to excess.

The Health Foundation recommends trying truly bold policies, such as extending the principle of the sugar tax to force food firms to remove unnecessary fat, salt and sugar from other products and bringing in minimum unit pricing of alcohol, as Scotland has done.

Ministers should adopt “a new approach that looks beyond the NHS to focus on the drivers of ill-health”, the thinktank says. Labour last year unveiled a 10-year health plan to both fix the NHS and improve the population’s health, especially through a “big shift” from treatment to prevention. But progress so far is slow and the results visible in only a few places. At the moment, worsening public health is outrunning the grand plan to turn it round. Time is running out.