Diets: Follow the stars and lose weight (constellations, not celebs)

You're carrying a bit of weight round your middle. I can see a Mars bar in your bag and I can tell from a glance that your BMI is waaaay off. Don't tell me – you must be a Gemini.

No, it's not a lost transcript of the Sherlock Holmes tale The Speckled Gastric Band, where our hero deduces why his clients are lardy via the movements of the stars, but the latest eating plan, the zodiac diet, devised by an astrologer and purporting to help you stay a healthy weight by analysing your star sign.

Yes, you might think I'm talking out of my Aries, but it exists – and, if you think about the cabbage soup diet or sipping Slim-Fast slime in a bid to shape up, maybe it's not a Pisces take after all.