LONDON - Obesity is now a greater threat to global health than hunger, a new Lancet study has found.

More than one in eight people in the world are clinically obese as the number passed one billion for the first time.

It is now the leading form of malnutrition with the number of people considered underweight falling to below 550 million.

Being obese or underweight are forms of malnutrition because in both cases people are not getting the right nutrients, vitamins and types of calories that are needed to be healthy.

Experts warned that children were paying the price for inaction on obesity by global leaders with under 18s accounting for 159 million of those who are now obese.

A further 879 million adults were considered obese, bringing the total to 1.04 billion out of the world’s eight billion people in 2022, according to the largest study of its kind.

NHS leaders called the study’s findings “alarming” and said obesity rates were “a ticking health timebomb”.

The analysis by a global team of experts, led by Imperial College London and World Health Organisation (WHO), revealed that the proportion of women who are obese has doubled since 1990 to almost one in five, and tripled among men to around one in seven.

In the UK, which ranked 78th out of 200 countries analysed for adult obesity levels, almost three in 10 adults were obese, with women slightly more likely to be overweight than men.

The researchers compared obesity and underweight levels around the world to 1990, when only 226 million people, or fewer than one in 20, were obese, including just 31 million children.

Meanwhile, the number of underweight people has come down over the same period, from 440 million to 347 million adults, and 219 million to 185 million children.

In the UK, one in 10 girls are obese and one in eight boys are, more than double the proportion seen in 1990.

Prof Simon Kenny, the NHS clinical director for children, said: “These figures will be as alarming to parents as they are to the NHS.

“Obesity affects every human organ system, and so at a young age can have a major impact on a child’s life, increasing their risk of Type 2 diabetes, cancer, mental health issues and many other illnesses, which can lead to shorter and unhappier lives.”

He said the NHS had set up 30 specialist clinics for people and families affected by extreme weight issues, but that the health service “cannot solve this issue alone”.

“Continued joined-up action by industry and wider society is needed if we are to avoid a ticking health timebomb for the future,” he added.

Professor Majid Ezzati, study author at Imperial College London, said it was “very concerning that the epidemic of obesity that was evident among adults in much of the world in 1990 is now mirrored in school-aged children and adolescents”.

People were considered obese if their Body Mass Index (BMI) was 30kg/m2 or over, and underweight if it was 18.5kg/m2 or less.

The data, which looked at 222 million people from 3,663 separate studies, shows that obesity is most prevalent in countries in Polynesia, such as American Samoa where more than three in four people are obese, the Caribbean, the Middle East and North Africa.

Dr Tedros Adhanom Ghebreyesus, WHO’s director general, also called on the food industry to play its part in tackling the obesity crisis.

He said it would “require the cooperation of the private sector, which must be accountable for the health impacts of their products”.

In Britain, obesity costs the NHS around £6.5 billion a year and is the second biggest preventable cause of cancer. It also increases the risk of diabetes and heart disease.

The Government’s current strategy on obesity has involved a levy on sugar in soft drinks, adding calories to menus and restricting where foods high in fat, sugar and salt can be placed in supermarkets.

But scientists say more needs to be done, with a ban on junk food adverts and the introduction of warning labels on unhealthy foods, among the proposals being put forward.

Prof Tim Spector, founder of nutrition company Zoe, told the House of Lords’ select committee on food, diet and obesity, that the Government’s current guidelines were “hopelessly out of date”.

“They are still proposing that people have low-fat spreads instead of whole foods or cheese or whatever, so very behind the times,” he told Peers.

“There’s nothing in there about eating whole foods instead of heavily processed foods.

“Even the NHS guidelines are very out of date. They state things like ‘you should never miss a meal, and you should snack regularly throughout the day’, and again focus on low-fat foods which all recent evidence and virtually every nutrition colleague I speak to doesn’t believe.”

He said it was “always the same committee that marks their own homework” and called for an overhaul.