A very interesting law of nature. It explains why all things living respond very favorably to varying forms of demands made upon them. This law also explains why all things living respond very disappointingly to most forms of socialism by reducing or eliminating demands made upon them. Well intentioned benevolence of reducing demands on people and other life forms has often very disappointing and unanticipated outcomes.
There are hundreds, maybe thousands of diet fads, and potions and lotions that promise weight loss. Most of them result in short term weight loss and longterm additional weight gain.