Deaths from coronavirus are ten times higher in countries where more than half the population is overweight, according to a new study — with the UK ranked among the worst countries.
Analysis by the World Obesity Federation (WOF) shows a link between those countries that have suffered worse in the pandemic and those where obesity is a particular problem.
The UK is ranked fourth in the world for its obesity rate and has recorded the third highest Covid death rate in the world.
The WOF believes hundreds of thousands of deaths could have been avoided if countries had done more to reduce obesity among their populations with nine in 10 Covid-19 deaths occurring in countries with high levels of obesity.
Age is the single biggest risk factor for death and severe disease from Covid-19 according to government scientists but obesity is one of a number of underlying conditions that is known to increase the chances of a patient having a more severe infection or dying.
The UK government is expected to announce new efforts to combat obesity on Thursday to coincide with World Obesity Day.
The WOF report said 2.2 million of the 2.5 million global deaths were in countries with high levels of obesity. They added that countries with low levels of obesity, lower than 40 per cent of the population, had a low Covid death rate of no more than 10 people per 100,000.
At the same time, the study finds every country with high Covid death rates of 100+ people per 100,000 has more than 50 per cent of their population overweight.
For example, Vietnam has the lowest Covid death rate in the world and the second lowest levels of population overweight, while the UK has the third highest Covid death rate and the fourth highest obesity rate.
Author of the report Dr Tim Lobstein, senior policy adviser to the World Obesity Federation and visiting professor at the University of Sydney, said: "We now know that an overweight population is the next pandemic waiting to happen.
"Look at countries like Japan and South Korea where they have very low levels of Covid-19 deaths as well as very low levels of adult obesity. They have prioritised public health across a range of measures, including population weight, and it has paid off in the pandemic.
"Governments have been negligent and ignored the economic value of a healthy population at their peril.
"For the last decade they have failed to tackle obesity, despite setting themselves targets at United Nations meetings.
"Covid-19 is only the latest infection exacerbated by weight issues, but the warning signs were there. We have seen it in the past with Mers, H1N1 and other respiratory diseases."
Johanna Ralston, chief executive of the World Obesity Federation, said: "The failure to address the root causes of obesity over many decades is clearly responsible for hundreds of thousands of preventable deaths."
The World Health Organisation said the report was a "wake-up call" for governments to tackle their obesity problems.
Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: "The correlation between obesity and mortality rates from Covid-19 is clear and compelling.
"Investment in public health and coordinated, international action to tackle the root causes of obesity is one of the best ways for countries to build resilience in health systems post-pandemic. We urge all countries to seize this moment."