Here is the original report:
The source is a company investing in, among others, sustainable agriculture, so some bias. I've also not read the actual report yet. That said, their summary raises an interesting point about the relationship with being overweight.
A carrot with half the potassium means eating twice as many carrots to get the same benefit. In countries like the UK, this decline is partly masked by eating more
Could soil degradation be a factor in the obesity epidemic? Interesting thought.
but that buffer is shrinking. GLP-1 weight-loss drugs are projected to reach over 100 million users in higher-income countries by 2030 and reduce food intake by 16 to 39%, while rising CO2 and degraded soils threaten to push nutrient levels down further.
Together, these pressures could leave around 5 million UK working-age adults below safe levels of essential vitamins and minerals.
Not sure why they're only reporting numbers for working age adults. Anyway, 5m is approx. 11% of the population aged 15-64 (thanks Wikipedia).