World Health Organisation research shows 64 percent of UK adults are overweight, including 28 percent who are obese, making Britain the fattest nation in western Europe.
But the study also warns that lifestyle trends here mean the situation is likely to get worse.
Data compiled since 2000 suggests a staggering 37 percent of UK adults are expected to be obese when rates peak in 2033/34.
Currently, Turkey and Malta have a greater proportion of their population who are obese while Israel also has higher levels of obesity.
But Dr Kremlin Wickramasinghe, who lead for non-communicable diseases in Europe, pointed to Britons being at the forefront of lifestyle trends that involve more people spending time in front of screens and ordering food deliveries.
He said: “The UK is ahead in western Europe where we see a particular lifestyle, with more digital screen time and the food environment in supermarkets, leading to increased obesity.
“You see the same in other countries but in the UK you see a greater proportion having online deliveries and [being exposed to fast food] advertising.”
In forecasts of future rates of obesity, conducted by the University of Groningen in the Netherlands, only the US fared worse than Britain – with 44 percent of adults expected to be obese by 2031.
The who European Regional Obesity Report 2022 highlights sedentary lifestyles where people increasingly stay at home in front of screens and socialise more online.
It also flagged the prevalence of food delivery services – such as Deliveroo and Just Eat – as well as online supermarket deliveries. It said: “Evidence suggests that food and beverages purchased from the outof-home sector are more energy-dense and higher in fat, sugar and salt than their retail counterparts.”
“Portion sizes are often larger, which encourages overeating, particularly if there is little price differential between portion sizes. The UK Government suggests regular overconsumption of a small number of calories can lead to individuals becoming overweight or having obesity and this can be exacerbated by eating out.”
The report was published to coincide with the European Congress on Obesity in Maastricht, Netherlands.
It cites UK research showing that eating out accounts for 20 percent to 25 percent of adult energy intake. This, or ordering a similar takeaway meal, resulted in people consuming on average 200 more calories per day than if they had prepared their own food at home.
Dr Wickramasinghe said: “The proportion of the population covered by these takeaways and online food deliveries is very big in the UK compared to other countries.”
“So more and more screen time and sedentary lifestyles are contributing to the increasing levels of obesity.”
Researchers also warned child obesity in the UK appeared to have worsened significantly in the pandemic.
A Deliveroo spokeswoman said: “Our outlook on health is simple – we want to provide the right information and a greater selection of healthier choices on our platform.”
A Just Eat spokesman said: “We are an online marketplace that works with over 60,000 restaurants, serving a diverse range of over 100 cuisines.
“Many already offer healthier menu options and smaller portion sizes so customers can make the choices right for them and their families.”