The small amount of oil you need to use in air frying is the main difference. You just get the same crispy layer and taste in air frying using only one tablespoon of oil whereas deep frying requires you to submerge the food completely in hot oil. Air fried foods contain 70-80% less calories than deep fried ones. Air frying is also less likely to produce carcinogens than deep fryers. So, air fryers are a healthy alternative to deep fryers.