So much for the concept of a sugar high
:
What limits willpower? Some have suggested that it is blood sugar, which brain cells use as their main energy source and cannot do without for even a few minutes. Most cognitive functions are unaffected by minor blood sugar fluctuations over the course of a day, but planning and self-control are sensitive to such small changes. Exerting self-control lowers blood sugar, which reduces the capacity for further self-control. People who drink a glass of lemonade between completing one task requiring self-control and beginning a second one perform equally well on both tasks, while people who drink sugarless diet lemonade make more errors on the second task than on the first. Foods that persistently elevate blood sugar, like those containing protein or complex carbohydrates, might enhance willpower for longer periods.
The point of the article is that human beings essentially have a limited amount of willpower. Consequently, you can increase your willpower simply by exercising it.
Imagine that.