If you’re looking to sharpen your focus and concentration, don’t use quick fixes like energy drinks and sugary snacks, and don’t worry if you can’t carve any extra time out of your schedule for things like meditation. All you need is to eat the right foods — most of them things that you probably already have in your fridge. These 15 items are part of a healthy diet that will help keep your energy high and your stomach satisfied as you use their brain-boosting properties to achieve maximum levels of concentration simply by stuffing some food into your face.

1. Oatmeal

Start your day with a concentration boost by eating a bowl of oatmeal. According to Health Magazine, oatmeal is one of those foods that will help you stay fuller for longer, leading to less distraction due to a growling stomach.

2. Salmon

Salmon is a great source of omega-3 fatty acids, which are extremely good for your brain. They help rebuild brain cells, slow cognitive decline and strengthen the memory-related synapses in your brain, health coach Lori Shemek tells Health Magazine. Salmon’s essential fatty acids may be vital in preserving memory, so if you want to stay sharp, choose fish over red meat.

3. Dark Chocolate

Dark chocolate has a myriad of health benefits, including the ability to boost blood flow to the brain, release endorphins and reduce sleepiness due to the theobromine it contains. While eating too much dark chocolate can cause jitteriness, small amounts will help with memory (due to the increased brain blood flow) and concentration (due to the increased serotonin levels it causes).

4. Blueberries

Livestrong reports that a study presented in 2010 suggested that eating berries may help prevent age-related memory loss and mental decline. Blueberries are high in flavonoids, which recent research has shown may improve memory, learning and general cognitive function, including reasoning skills and decision making.

5. Water

Even mild dehydration can cause fatigue, moodiness, headaches and problems concentrating in women, according to a study conducted in 2012 by the U.S. Army Research Institute of Environmental Medicine. The women in the study experienced more confusion when they were dehydrated and reported that it was harder to get things done; similar results were found when men were studied. So if you’re having trouble concentrating, the problem might just be that you need to drink more water.

6. Green Tea

Green tea will help hydrate you just like water, but with the added benefit of L-theanine, which has been shown to improve memory and attention. When combined with caffeine (which green tea contains a small amount of), L-theanine helps improve both mood and cognitive performance. As long as you’re not ingesting too much sugar with your tea, drinking a few cups a day is a great way to give yourself a mental boost.

7. Leafy Greens

A 2006 study in Neurology showed that “people who ate two or more daily servings of vegetables, especially leafy greens, had the mental focus of people five years their junior.” Greens like spinach, which contains high levels of potassium, help make the brain more responsive by increasing the speed of signals sent between neurons. Not too shabby for salad ingredients.

8. Bananas

Bananas, like spinach, contain lots of potassium, as well as high levels of Vitamin B6. This vitamin helps boost serotonin levels, giving your body the benefit of less fatigue and improved concentration along with that serotonin-induced good mood.

9. Coffee

Caffeine is a stimulant, so the right amount of coffee will actually help you concentrate instead of making you bounce off the walls. According to Livestrong, a 2005 study from the Medical University at Innsbruck, Austria, used fMRI scans to determine that caffeine promoted “increased activity of the anterior cingulate and the anterior cingulate gyrus in the prefrontal lobe of the brain.” These areas are involved in planning, attention, monitoring and concentration.

10. Beets

They may be gross, but beets help promote blood flow to the brain. This helps improve mental performance, as well as possibly fight the progression of dementia in older adults. Throw some beet juice into your smoothie or toss some roasted beets on your salad; you’ll never even notice the taste (maybe).

11. Eggs

The breakfast of champions contains all nine essential amino acids. Two of these are choline and lutein, which are very important to memory, thought and cognitive function. The yolks are also a good source of omega-3s, which, as you may remember from the salmon, are extremely useful to the brain.

12. Avocados

The healthy monounsaturated fat in avocados helps enhance communication between brain cells. It also helps reduce arterial plaque, leading to healthy blood flow to the brain. The good fat and hefty dose of fiber in avocados will keep your brain sharp and your stomach full, so go wild and smash some avocado into everything!

13. Yogurt

The combination of protein and calcium in yogurt helps you focus, Amy Jamieson-Petonic, MEd, RD, tells the Huffington Post. Tyrosine, an amino acid found in yogurt, produces the neurotransmitters dopamine and noradrenalin, which both improve alertness and memory.

14. Nuts

Containing high concentrations of Vitamin E, folate, magnesium and omega-3s, tree nuts have been linked to improved cognition. Almonds, for example, boost neurotransmitters linked to memory, while walnuts improve critical thinking ability. Keep a container of nuts in your desk for times when you’re feeling hungry or unmotivated; the delicious little nuggets will help you get that focus back and power through the rest of the day.

15. Mangoes

Mangoes are high in potassium, which will keep your energy levels up. This sweet, orange-yellow fruit is also contains lots of glutamine, which has been associated with improvement in memory in rats and is often said to do the same for humans. Although this hasn’t been definitely proven, there’s no doubt that glutamine is essential for normal brain function — and let’s not forget that mangoes taste good and are a great source of the antioxidant Vitamin C, which will help keep your immune system healthy and allow you to concentrate on work rather than on getting sick all the time.