Apart from time spent resisting temptation and just getting tired from a full day’s work – what else should you know of that will deplete your willpower?

Lack of sleep

Your willpower may dwindle as the day progresses, but you can enjoy peak willpower levels the moment you wake up every morning.

Your mind is fully rested and your willpower levels are replenished after a goodnight’s sleep.

But if you fail to rest up properly during the night, not only will your focus and concentration suffer, but your willpower and ability to make good decisions will suffer, too.

Kelly McGonigal, Ph.D., author of The Willpower Instinct, advocates the importance of getting a good night’s rest:

“Sleep deprivation (even just getting less than six hours a night) is a kind of chronic stress that impairs how the body and brain use energy. The prefrontal cortex is especially hard hit and it loses control over the regions of the brain that create cravings and the stress response. Unchecked, the brain overreacts to ordinary, everyday stress and temptations. Studies show that the effects of sleep deprivation on your brain are equivalent to being a little bit drunk!”

Luckily, poor self-control caused by sleep deprivation can be easily reversed just by getting more sleep. Here’s Kelly:

“The good news is any step toward more or better quality rest can be a real boost to self-control. When the sleep-deprived catch a better night’s sleep, their brain scans no longer show signs of prefrontal cortex impairment.”

Staying up late

At the very end of your day, your willpower will surely be running on empty. And instead of going to sleep to rest to regain your energy, you will have to eat food to sustain your inner night owl.

What food might that be? Chances are you’ll eat whatever your heart desires.

After a full day’s worth of making decisions, your mind is exhausted. Your capacity for self-control is very low.

It would be in your best interest to try to avoid making big decisions late in the evening.

Here’s Roy Baumeister on our evening willpower levels:

“Diets are broken in the evening, not the morning. The majority of impulsive crimes are committed after 11: 00 p.m. Lapses in drug use, alcohol abuse, sexual misbehavior, gambling excesses, and the like tend to come about late in the day.”

Decisions

Making decisions

In the Paradox of Choice, Barry Schwartz emphasises that we live in an world that is abound with choice.

What types of jeans to wear, what type of beer to drink, what type of restaurant to eat in…the list is endless.

He claims that this abundance in choice can in reality be more paralysing than liberating.

Because of so much choice out there, we really need to pick our (choice) battles. That is, we need to be selective in our decision-making.

Here’s Barry:

“We must learn to be selective in exercising our choices. We must decide, individually when choice really matters and focus our energies there, even if it means letting many other opportunities pass us by. The choice of when to be a chooser may be the most important choice we have to make.”

There is an abundance of choice in the world but your willpower is limited.

The odds are stacked against you and that’s why you should be selective in your decision-making.

Thinking about making decisions

Interestingly enough, ego depletion doesn’t only happen due to active decision-making.

In fact, research suggests that we can drain our own willpower just by watching or imagining others making decisions.

In an experiment by Vohs and Faber (2007), participants were required to put themselves in the shoes of fictional waiters who were forbidden to eat while working in a gourmet food restaurant.

The participants had to exercise self-control by merely imagining being a waiter and thinking of the various difficulties one might have when trying to resist eating food on the job.

Later, the participants were shown pictures of watches, cars, and other appliances, and were asked to rate how much money would they be willing to pay for them.

It was found that this imagining of being in the shoes of a waiter led the participants to be willing to spend more on these goods compared to the control group (i.e. the group that didn’t imagine being a waiter).

Because of this, they had much less self-control that would stop them from spending more money on certain items later on.

The main lesson from this piece of research is to conserve willpower and use it wisely.

After all, if self-control is exercised on one thing, then you’ll be less likely to exercise self-control successfully on another thing.

In his book Impulse: why we do what we do without knowing why we do it, Dr. David Lewis illustrates this point nicely:

“Refrain from having a fight with your partner before leaving for work and you may find it harder to control your irritation with a colleague later in the day. Refuse a second helping of strawberry cheesecake at lunch and you may find it far harder to resist a high-calorie snack in the afternoon. (…) This resource is easily exhausted and, once depleted, the likelihood of self-control failure increases. Ego depletion may occur, for example, in people who have been trying to stop thinking about food all day or coping with a stigmatised social identity. (…) The more we have to employ self-control in one area of life the less there is available for use in another.”

Low blood sugar

It might just make up 2% of our body mass, but the brain consumes 75% of all our blood glucose. Naturally, whenever we experience low blood sugar, our brain is being starved of very fuel it needs to function properly.

Ever heard of the term ‘hangry’? It stands for hungry when angry. The irritability that you experience when hungry is your brain’s way of telling you that it’s struggling to function optimally.

Your more rational part of the brain starts to shut down and any sense of self-control goes out the window.

As Dr. David Lewis puts it:

“Low blood glucose has been associated with such problems as lack of self-control, aggression, criminality, poor emotional control, impulsivity, difficulties in coping with stress and giving up smoking.”

You can learn more about this trend of research in next week’s post (sign up for an update so you don’t miss it).

Poor nutrition

What you eat and how you nourish yourself also influences your willpower.

Not only should we eat regularly to avoid low blood sugar levels, but we should focus on eating food that is healthy and nutritious.

Kelly McGonigal, Ph.D., author of The Willpower Instinct, mentions the importance of diet:

“Nutrition comes into play because it also influences how available energy is for the brain. Something as simple as eating a more plant-based, less-processed diet makes energy more available to brain and can improve every aspect of willpower from overcoming procrastination to sticking to a New Year’s resolution.”

Stress

In an earlier post on cravings, I mention a useful conceptualisation of our brain and how we are governed by two systems: the ‘hot’ system and the ‘cool’ system (for more on that, click here).

What stress does is it accentuates the ‘hot’ system and attenuates the ‘cool’ system. That’s why we struggle to resist temptations and fail to exercise self-control when under stress.

Here’s Kelly:

“The fight-or-flight response floods the body with energy to act instinctively and steals it from the areas of the brain needed for wise decision-making. Stress also encourages you to focus on immediate, short-term goals and outcomes, but self-control requires keeping the big picture in mind.”

In a nutshell

What depletes your willpower

Lack of sleep and staying up late

Making decisions and thinking of making decisions

Low blood sugar (being hungry)

Poor nutrition

Stress

P.S. Thanks for reading. If you liked this, feel free to sign up to my free weekly newsletter for more psychological insights into everyday life.

More posts on willpower:

– What You Need To Know About Willpower

– How to Improve Your Willpower