Hello,
why not simply connect a currency to the healthy calorie requirement (probably between 1000-2500 Kcal per day) of an average citizen of the world. A coin, let's simply call it "Foodcoin" has a defined, regulated & globally communicated value. Namely the worth of the global average food price to cover the calorie requirement by one month. The basis is always the price of the food, which is available on a global scale in most cases, i. e. the simplest one (e. g. bread, potatoes, rice). The whole thing is regulated by the conscious creation and destruction of coins. Always with the aim of keeping the value very constant and protecting it from speculators.
What are the advantages and disadvantages?