" The most price elastic food item is eggs, at 0.32. This means if the price of eggs goes up 1 percent, consumption goes down 0.68 percent. Eggs are the highest-quality protein there is. Eggs have all the nutrients you need. They are literally the world’s most perfect food. And people won’t buy them if the price increases. Why? Because there’s nothing in an egg that has hedonic properties. Tryptophan (the precursor of serotonin) sure, but can it drive dopamine? Conversely, the most price inelastic consumable is fast food, at 0.81. This means if the price of fast food goes up 1 percent, consumption only goes down 0.19 percent. And the second most? Soft drinks, at 0.79. These two food items exert the most hedonic effects (due to sugar and caffeine) and happen to be the ones that people will consume no matter what. And of course they are the most addictive. So how can society turn an addicted, depressed, drug-addled, corpulent, and metabolically ill populace around? "

― Robert H. Lustig , The Hacking of the American Mind: The Science Behind the Corporate Takeover of Our Bodies and Brains