Willpower, Glucose, and Belief

It looks like journalists are short on willpower. They give into the temptation to jump to conclusions. At least they do when they report on willpower research. Read one article, and we have a limited supply of willpower. If we use it up, then we simply can’t be held accountable for how much junk food we eat while dithering away the evening watching television.

Contrary to that, a spate of articles about a recent study tells us that it’s all in our minds; it depends on what we believe. This gives new traction to the Henry Ford quote, “If you think you can do it, or you think you can’t do it, You are right.”

However, I think the research tells us that the first step to more willpower is a step away from simple nostrums. The art of willpower looks more like a busy box than a one-step instruction.

Willpower is in Limited Supply?

We should start with asking what it is that researchers are researching when they research willpower. First, they may not even use the word. Instead, they might call it self-regulation or self-control. Sometimes self-regulation means something like homeostasis, as when our bodies keep us at the right temperature, but both self-regulation and self-control can also refer to willpower, the force with which one can, “exercise of control over oneself” according to a standard or goal.

When we seek willpower, we are seeking one (or a combination) of the following three things (it gets more complicated, but we’ll save the additional details for another time):

  1. Restraint against impulses (as in resisting the ice cream)
  2. Force against resistance (as in staying on task)
  3. Force over limitations or weakness (as in persisting despite getting cold, tired, or hungry)

This is starting to look a lot like Ohm’s law, for those of you that are into electricity (as in force divided by resistance equals current).

This three-factor view raises some questions. If you are trying to run five miles, how much of the effort is in running, and how much is in resisting the urge to turn right and get a cold one at the Plan B Bar? If you’re working on a term paper, how much of the challenge lies in managing your blood sugar (glucose), and how much lies in your self concept?

First, consider the truism that willpower comes in a limited daily supply. Willpower is usually compared to a muscle, and there is an apt comparison here, because your supply of strength depends on whether you have consumed proper fuel, restored the fuel when it is depleted, and used the work-rest-work principle to get the most out of your strength. This is hardly a specified daily supply. Like muscular strength, our strength of will varies with our nutritional status. This includes our blood sugar level, according to fairly recent research. But please don’t use that as an excuse to surrender to too much sweet temptation. After all, rationalization is really just a way to sabotage our will power when we still have some left.

Imagine how many other health and nutritional factors would weigh in if researched in this regard? And then there are sleep and exercise, which might as well be nutrients, since they are mission-critical when it comes to willpower.

Willpower is in the Mind?

But what about the idea that willpower is all in the mind. Set aside for now the question of where the mind is. Should I find mine, I’ll venture an opinion at a later time. Suffice it to say that recent research has shown that willpower is greatly affected by what we believe about how much we have. The researchers point out, however that this does not deny that other factors also affect willpower.

What is notable about the recent study on this question is this: people who were led to believe that willpower is not in limited supply took shorter breaks and ate less junk food. This suggests that, when it comes to the muscle of will, the work-rest-work principle demands only moderate rest and carbohydrates in order to serve you quite well.

Thus, you needn’t bulk up on carbs to win the willpower battle, but you must wean yourself from indulgent beliefs about it. Gandhi said, “Strength does not come from physical capacity. It comes from an indomitable will.” But where, exactly does this indomitable will come from? Apparently a good measure of it really does come from believing in it.


Baumeister, R. F. and Vohs, K. D. (2004). Understanding self-regulation: An Introduction, in Handbook of self-regulation: Research and theory. The Guilford Press.

Gailliot, M., & Baumeister, R. (2007). The Physiology of Willpower: Linking Blood Glucose to Self-Control Personality and Social Psychology Review, 11 (4), 303-327 DOI: 10.1177/1088868307303030

Job, V., Dweck, C., & Walton, G. (2010). Ego Depletion–Is It All in Your Head?: Implicit Theories About Willpower Affect Self-Regulation Psychological Science, 21 (11), 1686-1693 DOI: 10.1177/0956797610384745

Robert A. Yourell, MA

Robert A. Yourell, MA, has extensive experience in the mental health and social services dating back to 1975. His training includes Ericksonian communication and hypnosis with John Grinder, Eye Movement Desensitization and Reprocessing with Francine Shapiro, PhD, Body Integrative Psychotherapy with Jack Rosenberg, PhD, and solution-focused psychotherapy. He provides free audio experiences on his site that include bilateral sound and Shimmering.
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