Robert Krulwich and Jad Abumrad of RadioLab interviewed a scientist who did a study giving individuals 2-digit numbers to remember. He then, sent them down a hall to another room. While on their way to the next room a woman stops and offers them a fruit bowl or a slice of chocolate cake. This was repeated with people who were given a 7-digit number to remember.
The result was that those who had only a 2-digit number to remember made the ‘healthier’ choice than those who had to remember the 7-digit number. It shows that our brains when overloaded can not make good food choices. No wait. When our brains have too much to keep track of, too many events for the day, our ability to make better choices for ourselves markedly reduces.
That is why I am fat. I have been walking around my whole life trying to remember that 7-digit number.