The Mibbs-Spagmo Theory of Gluttony is a book written by a woman named Mibbs in Fable III.
Fast travel to Organic Ink (tattooist) shop, a large(r) white building on the southern edge of the Eco Warrior camp in Mourningwood, just left of the Happy Hippies' Hut. Head left (around the shop) and find the book atop a small group of crates. (The crates are stacked between the shop and a nearby large wooden platform.)
The first core principle of our economic theory can be summarized thusly: greed is good for you. Now, let us clarify who we mean by 'you': not you. At least, not directly. Greed is directly good for the government, because the more you spend to acquire material possessions, feed your family, etc, the stronger the economy becomes, and the more the goverment earns in taxes. A strong economy coupled with a strong government creates an environment in which progress is limitless and virtually anything is possible, and therein lies the 'indirect' benefit of your greed. Of course, given your greediness, you will likely not survive long enough to benefit from society's affluence, being grossly overweight yourself, but think of your children. Yes, they will be predisposed to obesity and an early death just as you were, but their short lives will be far more luxurious than yours. Which brings us to the second core principle: quality is more important than quantity.