It’s 1817. King George III still sits on the throne. The dust is settling from the Battle of Waterloo. And Dr William Kitchiner is scribbling down the secret to a delicious new snack.

First, peel potatoes ‘like lemons’ writes the eccentric Kitchiner in his ‘Cook’s Oracle’. Then ‘dry them in a clean cloth before ’frying them in lard or dripping’. It was the recipe that would launch a thousand weight battles and kick off our ongoing love affair with the humble crisp, according to Secrets of Our Favourite Snacks (Channel 4, 23 May, 8pm).

Fast-forward 200 years, and we Brits now munch our way through £2.8bn of savoury snacks each year. That’s seven bags of crisps per week, per person, on average. So obsessed are we with our next crunch that a trendy Soho restaurant gets away with charging £11.50 for a large crisps complete with katsu curry and salted caramel dips.

As presenter Sophie Morgan pointed out: “We don’t need them, we can live without them.” So why are we stuffing ourselves silly with high-calorie, high-salt starch? Turns out it’s got nothing whatsoever to do with a complete lack of self-control. No, really.

We are in fact “hard-wired” to reach for temptation, Morgan discovered, with our brains lighting up at the mere mention of a pack of cheese & onion. We’re little better than heroin addicts searching for a fix as we stream into supermarkets lined with colourful packaging and fancy new flavours.

Health campaigners may as well give up, shut up and let us snack in peace. Thank God for that. Crisp, anyone?