The failure to tackle the UK's obesity crisis is down to successive governments being guilty of weak policy design, lack of effectiveness and botched implementation.

That is the message of a hard-hitting report – published this week – which studied 14 government obesity strategies published from 1992 to 2020, containing a total of 689 wide‐ranging policies.

According to the study, the approach taken by governments to their own policies has "destined them to fail", as there has been a reliance on attempting to influence individuals to change their behaviours – rather than changing unhealthy environments.

There has also been a reluctance to learn from any previous failures – or very rare successes.

The study – conducted by a team at the University of Cambridge and funded by the National Institute for Health Research (NIHR) – doesn't pull any punches: "Our study has provided new evidence that in almost 30 years, the UK government has proposed 689 wide‐ranging policies to tackle obesity in England but has not yet successfully and consistently reduced obesity prevalence or health inequities," say the report's authors – Dolly Theis and Martin White.

"Only one of the 14 government strategies commissioned an independent evaluation of previous government strategies for obesity, which suggests a significant deficit of government policy learning and may explain why similar or identical policies are put forward multiple times over many years.

"Many of these policies were set out in a way that does not readily lead to implementation, and the largest proportion of policies did not fulfill any of the implementation viability criteria.

"Overall, governments have adopted less interventionist policy approaches, although this has changed in recent years.

"The policies have relied on a 'high agency' design that relies on individuals to make behaviour changes, rather than shaping external influences such as the environment or economy and are thus less likely to be effective or reduce health inequities.

"We found that a wide range of inadequacies related to government obesity policies are likely to explain why governments have repeatedly failed to reduce the inequalities in, and the prevalence of, obesity.

"To increase the likelihood of policies being implemented, governments should accompany policy proposals with information ensuring they can readily lead to implementation, such as a clearly identified responsible agent, evaluation plan, and time frame.

"To increase the likelihood of effectiveness and equitability, governments should increasingly focus obesity strategies on 'low agency' population intervention policies that more comprehensively address the most powerful levers for system change."

Liz Terry, editor of HCM said: "COVID-19 preys on people with excess body fat and yet the government is failing to develop policies to address this or to sufficiently engage sectors – such as the health and fitness industry – which could be driving successful interventions.

"This is a hard thing to say, but as a society, the UK is at the eye of a perfect storm when it comes to the obesity challenge. Firstly, we are failing to teach children self-care, so they know how to eat well, exercise and lead a balanced life; secondly, society judges people who are overweight, creating a complex emotional and social minefield that needs to be unravelled before we can enable behaviour change and thirdly, we've cultivated a culture of dependency on the NHS, whereby too many people think they can live any way they choose without consequence and the NHS will fix them for free when it all goes wrong.

"As a society, we imbue the NHS with seemingly magical properties and view it as a huge comfort blanket that negates personal responsibility. It can indeed perform miracles, but testing it beyond its limit each day is not wise or sustainable.

"Over 75 per cent of all disease is lifestyle-related and the government must really refocus on prevention – not just talk about it – engage with the industries that can help and start creating change right now. Lives are being lost with every day we delay."

• To read the full report, click here.