Imagine a motorized belt that adjusts to your body when you sit down, or extends itself as your gut expands during a marathon eating session. French company Emiota has realized the dream, but it doesn’t end there because Belty can also track your waistline and measure your activity. Alongside the tiny motors there’s an accelerometer and a gyroscope. We’re told this will be a premium product, so expect a high price tag. But do we need one? You could argue that a standard belt is already pretty good at telling you when you’re getting fat via notch technology.