I have observed this many times when I was doing supermarket shopping… always when I go there hungry I buy too much food, but it’s not all, I also tend to buy more other goods (including cosmetics or electronics). There must be some subconscious psychological mechanism causing this behaviour.
It is obvious that if you buy too much food it is very often wasted = your money is wasted and lost. Other point is that if we eat too much we become fat and not healthy, which finally costs us more.
So what is the conclusion? Never go shopping when you are hungry!