The study found that many crops had lost 20% to 50% of several key nutrients… The decrease in nutrient and vitamin value is thought to be down to declining soil quality and crops being selectively bred for their ability to grow quickly, rather than there being any focus on their health benefits… It raises the prospect that the advice to eat five portions of fruit and vegetables a day, introduced in the UK in 2003, may need to be updated. The report added that people on weight-loss drugs could be most at risk from the lack of nutrients, as the treatments could cause them to consume less food…