In return they pay us in calories of food or fuel to cover the energy we expended, plus they give us extra calories which we can trade to other people for the services and goods we need. We might think we pay with money, but actually we pay with calories. We earn calories at our jobs, then we pass them on to others to support them, in exchange for their goods and services. The stuff we call money is just a token representative of calories. Without money we would have to carry around bags of food, and bottles of gas, or batteries with electricity.
Money is simply a token which represents calories and makes life a lot more convenient.
The only problem with money is that people get caught up in the illusion that it is real wealth. They manipulate numbers in an effort to make money, but they fail to create any real wealth. You can hear people doing this every day in advertising, get-rich schemes, and political speeches. Their proposals may seem sound according to the math, but if you think in terms of calories you will find that their plans seldom bring about real wealth. This book will help you to think about calories, rather than money, because the flow of calories points directly to real wealth.