What fuels our willpower?
That was the question on researchers minds as they tested the impact of a healthy breakfast on high school students. They split the students into 3 groups with different foods to see which would lead to the best behavior and academic performance.
The first group of students was given a healthy breakfast of low-glycemic foods like eggs, fruit and oatmeal.
The second group of students was given an unhealthy breakfast of high-glycemic foods like bagels muffins and Pop-Tarts.
And the third group was given no breakfast at all.
Without knowing which students were in each group, the teachers were instructed to rate each of the students on their behavior and academic performance during the morning periods from 8:00-10:30am. 
THE POWER OF WHAT YOU EAT
Across the board, students with the low-glycemic breakfast greatly outperformed the others on the measures of behavior and performance. They were focused, well behaved and genuinely interested in learning.
Then the students who ate the high-glycemic breakfast were graded well for the first hour, but after 9am, they started to act out and lose their focus.
Finally, the students who ate no breakfast at all performed the worst on both measures. They were undisciplined, unmotivated and inattentive throughout the entire morning period.
This all took place regardless of each students academic history, socioeconomic status, or school citations. "Bad kids" with the low-glycemic breakfast, outperformed "good kids" who ate the high-glycemic breakfast or no breakfast at all!
Clearly, what you eat has a significant impact on your willpower!
The reason why the students with the healthy breakfast performed so much better is because their food provided their brains with a consistent supply of glucose - what the brain uses to exert willpower. 
The students with the unhealthy breakfast had a quick spike of glucose - provided by the sugary foods - but this spike eventually crashed, leaving them without willpower fuel. And the students without breakfast had no glucose and thus no willpower.
THE 10 BEST FOODS FOR LONG-LASTING WILLPOWER
So what foods, exactly, will give you the most willpower? As a general rule, any low-glycemic foods like lean proteins, vegetables, nuts and fruit will all give you a heathy dose of long-term willpower. 
But here are the 10 best foods for long-term willpower. I included some from every major diet, so there should be something on this list for everybody:
All lean meats will give you a healthy dose of long-term willpower, but the best meats for you are poultry and fish. They have the most protein and the least fat, leading to the most health benefits.
However, if you are on a low-carbohydrate diet, you may want to choose fattier meats like beef, pork or lamb in order to get enough energy.
Click here to see the full list of health benefits poultry/fish.
2. Free-Range Eggs
Eggs are one of the most nutrient-rich and healthiest foods available – and they are almost remarkably good for your willpower! The mixture of protein and healthy fat creates a steady stream of glucose for your brain.
Ensure that you are eating free-range eggs, however. Regardless of any moral claims, chickens that are locked in cages produce eggs with Omega-6 fatty acids, rather than Omega-3 fatty acids. So the “good fat” becomes “bad fat”.
Click here to see the full list of health benefits of eggs.
Tofu is a great option for the vegans out there that want a steady stream of willpower fuel. Just ensure that when that you are eating tofu in its purest state.The more processing that foods go through from their natural production to your plate, the less willpower benefits you will get from it.
This is because usually high fructose corn syrup is added to the food during processing, which will lead to the spike and crash effect. So foods like tofu dogs, tofu nuggets and tofu burgers won’t help you very much.
Click here to see the full list of health benefits of tofu.
4. Split peas/lentils
Many legumes are low-glycemic, but split peas and lentils will give you the most willpower benefits. They have the least amount of natural sugar and therefore will have the least chance of producing the spike and crash effect.
Again, getting these in their most raw state will have the most willpower benefits for you. So skip the canned peas and stick to the ones straight from the pods.
Click here to see the full list of health benefits of these and other legumes.
5. Almonds/Almond milk
Almonds are perhaps the best snack food for your willpower. They have incredible benefits to your health, will quench your hunger and provide your brain with a long-term supply of glucose.
Almond milk is also preferable to cow’s milk or soy milk because of its low amount of sugar and carbohydrates. Although the other types of milk are perfectly fine, they will produce more of the spike and crash effect than almond milk.
Click here to see the full list of health benefits of almonds.
Yogurt is also a great snack food for long-term willpower. It is full of nutrients and contains less natural sugar than the milk it is created from, so it has more long-term willpower benefits.
Stay away from yogurt that has been processed or has added sugar, however. Many of the "snack sized" yogurts pre-mixed with fruit on the market will have little willpower benefits. Stick to plain yogurt and add the fruit yourself for long-lasting willpower.
Click here to see the full list of health benefits of yogurt.
Pick a berry, any berry. Berries are some of the best options for long-term willpower because of their lower sugar content relative to other fruit options like apples and bananas.
They also have the added benefit of being high in fiber and antioxidants, so they are by far the best choice as far as fruit.
Click here to see the full list of health benefits of berries.
Avocados are also a great fruit option for long-term willpower due to their relatively low sugar and high amount of healthy fats. These healthy fats have also been proven to help you absorb nutrients from other plant foods more effectively.
They also provide a very healthy alternative to butter or mayonnaise if you want to add a creamy texture to your food.
Click here to see the full list of health benefits of avocados.
9. Sweet potatoes
All vegetables will give you long-term willpower, but the best vegetables for willpower are root-based - and sweet potatoes are at the top of the list!
Sweet potatoes are some of the most nutrient-dense foods around and are possibly the best source of carbohydrates there is. There is even some evidence that they will help regulate your blood sugar level and thus improving the long-term willpower advantages.
Click here to see the full list of health benefits of sweet potatoes.
Carrots are another great snack food for long-lasting willpower. Like sweet potatoes, they are rich in beta-carotene which the body turns into Vitamin A for energy.
Although not quite as healthy as sweet potatoes, carrots are a much healthier carbohydrate option than breads or cereals.
Click here to see the full list of health benefits of carrots.
Your willpower acts like a muscle. And like other muscles in the body, it gets energy from the foods that you eat. There are plenty of foods that will help give your brain willpower fuel, but these 10 are the best available.
If none of these foods seem appealing to you, do not panic! As a general rule, the best foods for your long-term willpower are those that are non-processed.
Processed foods usually have added sugar or high-fructose corn syrup, which will always lead to the spike and crash effect. So choose healthy, natural foods and skip the processed foods. If you do that, you will see extraordinary benefits to your long-term willpower!
- Gailliot, M., & Baumeister, R. (2007). The Physiology Of Willpower: Linking Blood Glucose To Self-Control. Personality and Social Psychology Review, 303-327.
- Gailliot, M., Baumeister, R., DeWall, C., Maner, J., Plant, E., Tice, D., ... Schmeichel, B. (2007). Self-control Relies On Glucose As A Limited Energy Source: Willpower Is More Than A Metaphor. Journal of Personality and Social Psychology, 325-336.
- Pollan, M. (2009) Food Rules: An Eater's Manual. New York: Penguin.