Food safety campaigners have long been concerned about pesticide residues on lemons, limes and oranges – and now a social media post about it has gone viral. How safe is it to eat lemon cake or drink a G&T with ice and a slice?

Do you sprinkle citrus zest on to your cooking or drink hot water with a slice of lemon? According to an Instagram post that went viral last week, you shouldn’t. “Select citrus fruits at Lidl now come with a ‘Peel unfit for consumption’ warning,” posts @wholefoodwarrior. She photographs some of the supermarket’s labels, which list the post-harvest chemicals used to conserve the fruit: azoxystrobin and fludioxonil (limes) and imazalil, 2-phenylphenol, thiabendazole, pyrimethanil and fludioxonil (easy peelers), plus E903 in the peel’s wax coating (both).

The 10,500 comments on the post are largely appalled. So what are these substances? And how worried should consumers be?

A new report has found many crops are far less nutritious than they once were, so we need to eat more of them. Here is how to get your five portions of fruit and veg a day, easily and affordably – and potentially increase that to ten

When Eva Humphries first started working as a nutritionist, she met a client who had just found out he had high blood pressure and high cholesterol, and was on the verge of type 2 diabetes. He had no idea how to change his diet or lifestyle.

The man broke down and cried for 45 minutes, leaving Humphries with “no idea of what to do”, she says. In the final 15 minutes of the session, scrambling for a quick but helpful message, she finally said: “When you look at a plate of food, can you just make half of it veg for me?”