The fascinating book, Fast Food Nation, by Eric Schlosser, about how fast food has entirely changed how we farm, how we live, and how we eat. Do read it - it will motivate you to stop eating fast food! When McDonalds was forced to switch from beef tallow to vegetable oil in order to cook their fries, they had a problem, as the beef tallow was key to the special McDonald's french fry taste.Our sense of taste is actually quite crude - we can only discern sweet, salty, sour, bitter, and astringent tastes, whereas our sense of smell is extremely sensitive, and is believed to be responsible for up to 90 percent of the flavour we taste. When we chew our food, volatile gases are released which we smell. "natural flavours" are any healthier than "artificial flavours" is probably stretching the truth a bit, even though something designated as "natural" must come entirely from an herb, spice, vegetable, fruit, meat etc.