because you only spray on a thin layer cooking sprays are great for sautéing vegetables and lean meats with a small amount of oil. if you check the ingredients label you will see the primary ingredient is vegetable oil. while some are flavored to taste like butter others are flavored to taste like olive oil and may even contain some olive oil. here is an example list of ingredients in one brand of butter-flavored pan spray: soybean oil (adds a very small amount of fat) soy lecithin natural flavors dimethyl silicone (for anti-foaming) beta-carotene (for color) propellant. keep in mind that even cooking sprays labeled as "zero calories" can actually contain less than 1 calorie per serving. so they're not completely calorie free. you can actually make your own cooking spray by buying a spray bottle and filling it with healthy oil such as canola or olive oil.
what is in buttery-tasting pan sprays that make them taste like butter but without all the fat?