You are what you eat.

If “you are what you eat,” what are you?

I don’t know about you, but that question used to make me pretty uncomfortable. Before I learned how to change my eating habits for the better, I had packed on 40 extra pounds from poor eating. Not only did I look bad, I lost the momentum I needed to work the long, hard hours entrepreneurship requires.

Fortunately, there’s an enormous amount of information out there about the foods that are best for your body. Foods do different things for you, and you’ll find that some foods are especially beneficial for your brain and help facilitate mental processes like negotiation, willpower, and focus. Consider the following 15 options as you build a diet that’s designed to boost your productivity.

1. Berries

According to neuroscience research, dark-hued fruits and vegetables are the best foods you can consume to protect your brain against the effects of aging. And, as you might expect, by protecting your memory and other higher brain functions, you’ll enable yourself to be at your most productive each and every day.

2. Bananas

One banana holds the amount of glucose your brain needs for a whole day, which is why starting your day with a banana will keep your mind sharp and functioning well.

3. Eggs

Eggs contain a B-vitamin called choline that enhances memory and reaction time, giving you yet another reason not to skip breakfast!

4. Salmon

Sixty percent of your brain is made up of fatty acids, and salmon is packed with the best kind—DHA. Salmon is full of omega-3s, protein, B-vitamins, and iron—all of which help maintain memory, build focus, and support reasoning.

5. Eggplant

The nutrients found in eggplant keep your brain sharp by improving communication between brain cells and messenger molecules. That said, if you want to take advantage of these benefits, it’s important to use the skin of the vegetable. That’s where the nutrients you need in order to reap the maximum benefits are located.

6. Spinach

A diet rich in spinach slows down age-related brain declines, and can significantly improve learning capacity and memory. It also packs tons of antioxidants, which helps reduce toxins that damage cells.

7. Whole Grain Foods

Whole grain breads and cereals contain a higher percentage of folate than your other carb options. Folate boosts blood flow to the brain, keeping it working at peak levels throughout the day. As you might expect, this is seriously important for your productivity levels.

8. Walnuts

Besides looking surprisingly similar to the human brain, walnuts can do great things to help keep you productive. They contain roughly 15-20% protein, as well as omega-6 and omega-3s, fatty acids, vitamin E and vitamin B6—all of which are important for overall health. They may also help correct serotonin levels, controlling both your mood and appetite.

9. Caffeine

Coffee lovers rejoice! There are a host of positive benefits to be had from caffeine, including increased alertness, improved memory, and even helping your eyes focus on the computer screen for longer. For best results, though, hold off drinking it until about 90 minutes after you wake up, as this will allow the natural AM surge of cortisol—which would otherwise inhibit caffeine’s effect—to wear off.

10. Chocolate

Can this list get any better? If you’re in need of a sweet pick-me-up, dark chocolate contains antioxidant properties that help focus and concentration, while milk chocolate is good for improving reaction times and memory.

11. Green Tea

Freshly brewed green tea enhances both memory and focus. It also contains catechines, which help you stay mentally relaxed, but focused. Green tea also contains antioxidants that can help improve the efficiency and effectiveness of signaling within the brain as well.

12. Dark Leafy Greens

Dark greens have a ton of nutrients, including iron, which helps blood flow and improves cognitive control. They also contain vitamin K, which slows the brain deterioration that occurs with age. If a big salad doesn’t sound that appetizing to you, blend your leafy greens with a combination of citrus and berries to add sweetness.

13. Raw Carrots

Raw carrots have a low glycemic index, meaning that the glucose they contain is broken down slowly and helps fuel your brain at a steady pace all day. Avoiding glucose spikes steadies your mood and keeps your mind clear, letting you focus on your most important tasks all day long.

14. Broccoli

Broccoli is called a “superfood” for a reason. It’s also packed with an enormous nutrient load, including a great dose of vitamin K. As mentioned above, vitamin K plays a critical role in supporting your cognitive function and brainpower.

15. Sunflower Seeds

A great brain-boosting snack, sunflower seeds impact your mental processing powers and your overall mood. They’re rich in thiamine, a B-vitamin that increases cognitive function and memory. Skip the candy in the vending machine and reach for the sunflower seeds instead—your brain will thank you!

So there you have it—15 foods that’ll boost your brainpower and your productivity. When you eat in a way that works with your body instead of against it, you’ll find that it’s not that hard to feel good throughout the day. When you add these 15 foods to your daily diet, you’ll be able to say goodbye to energy spikes and drops and hello to steady focus and effective productivity.