There is no right or wrong way to lose weight, no guaranteed shortcut to dropping the extra pounds and becoming a new, svelte you. But learning the science behind appetite and overeating surely can’t hurt.

This video explores what goes on in our brains and bodies when we eat, overeat, and over-indulge. And brings our evolutionary forebears and genetic makeup into the mix.

The problem is that as hunter-gatherers our species took the opportunity to gorge as and when we could. We still have that innate desire lurking within us, but with high-fat, high-sugar food all around us.

This is just the science behind overeating, but it doesn’t suggest any ways of stopping it happening. The best you can do is break the cycle, by listening to your body when it tells you it’s full. But that’s easier said than done.