In the past couple of years John Lewis reported a 400% rise in sales of Air Fryers. But despite the recent craze, they were actually invented a long time ago. The earliest air fryer was invented by William L. Maxson in 1946 and called the Maxon Whirlwind Oven, which used a motor to circulate air. Used first for the military he then used it for Airlines like Pan Am which was able to use it for their passengers during cross Atlantic flights.
Did you know air fryers don't actually fry? Instead, the food goes into a perforated basket and the machine cooks the food by blowing hot air around it. The force of the air produces a convection effect that cooks and browns the exterior of the food in the basket. As long as the temperature of the air reaches around 320 F, breaded foods like frozen chicken tenders or unbreaded starchy items like chips should turn brown.
One drawback to the air fryer is that you can't cook foods dipped in liquid batter, as the batter can drip through the holes in the basket and make a big mess. It’s also not good for doughy foods like doughnuts or beignets. So, you're limited to breaded or dry-seasoned items.
As for their health claims – this is what the British Heart Foundation says:
“Air fryers work by rapidly circulating hot air, which gives food a crispy outer layer without having to add much, if any, fat. Turning 1kg of potatoes into air-fried chips for four people can be done with one tablespoon of oil, which would make them low in fat – lower than most oven chips you can buy, and a lot lower than deep-fried chips. So, if you often eat deep-fried foods, switching to an air fryer could be helpful."
If you’re cooking a food that you wouldn’t normally add fat to when you cook it, whether that’s ready-made oven chips, bacon, sausages or breaded chicken, being cooked in an air fryer is unlikely to make it healthier. Air frying or oven baking are both good ways to cook healthy foods such as fish, chicken without a coating, vegetables and baking potatoes.