For nearly 60 years, celebs have been extolling the virtues of the grapefruit diet to burn fat. From Miss America popping up on TV screens in 1957 to swear by a grapefruit at breakfast, to Aussie popster Kylie Minogue insisting a seven-day grapefruit diet was her “secret weapon” to banishing the bulge.

For those that took their words as gospel, the bang-on-trend Superfoods: The Real Story (C4, 8.30pm, June 29) may have left a bitter taste.

As revealed by the eternally upbeat Kate Quilton, the fat-busting chemical in the citrus fruit does exist. To get the full effects, however, you’d need to munch your way through about 40 whole grapefruits in one sitting, taking on nearly 5,000 calories and obscene amounts of sugar in the process.

That myth busted, the show went on to concern itself with superfoods claims with a little more substance. Sugar substitute xylitol, for instance, has turned into a bit of an obsession for the Finnish, but not without good reason - studies have proven its ability to fight tooth decay.

And then there’s kale. Be it juiced into vivid green smoothies served up in hip London health bars or cooked into over-priced crisps, you can’t move for the deep green vegetable at the moment.

It took Quilton a while to find out why, until she bumped into Franz at a German kale party (yes, they have those) who revealed a kale-heavy diet can boost eyesight. It probably isn’t quite the answer hipsters supping their kale and spinach shakes in Shoreditch were hoping for, but at least they’re better off than Miss America.