The year 1963 was surely one of the most significant of the 20th century. President John F Kennedy was assassinated, Martin Luther King delivered his “I have a dream” speech, and the Beatles recorded and released their debut album. But for all the huge political and cultural events, it was arguably an even more momentous year for public health: 1963 was the year cigarette sales peaked and began to fall in the US.

A generation from now, we may look back on 2020 in a similar way. Yes, there was the small matter of a global pandemic, but this may also have been the year obesity levels ceased their inexorable rise and began to descend.

Around the world, obesity rates have been stubbornly climbing for decades, if anything accelerating in recent years. But now newly released data finds that the US adult obesity rate fell by around two percentage points between 2020 and 2023.