We love a good glow-up. Whether it’s our favourite celeb’s “post-baby bounce-back” or an influencer’s body transformation reveal, we’re quick to double-tap the flat stomachs and hourglass curves. The ...

The belly button, it turns out, is one of the least-studied parts of the human body. But one of its great mysteries may now have been solved – why most people have an innie, or concave belly button.