Tea and coffee are the most consumed beverages worldwide following plain water, and there’s no doubt that a major reason why is because many people can use more energy.

Even if you generally have healthy habits—you eat a fairly balanced diet, work out and try to clock enough sleep most nights—you may still be struggling to stay as motivated and focused as you’d like. Fortunately, the addition of certain foods to your diet may help give you the mental edge you’re looking for and prevent you from feeling exhausted all the time.

The best “brain foods” are rich in protein, antioxidants, good fats, vitamins and minerals, which provide you with not only a quick source of energy but also protection against cellular damage that can lead to cognitive impairments.

Here are six foods that can help support cognitive function, alertness, memory and positive moods.

1. Eggs — Eggs are an easy to prepare, nutrient-dense source of protein, healthy fats, choline and B vitamins that help power your brain. Having a couple for breakfast (or really with any meal) is a far smarter choice than opting for sources of empty calories like cereal or a muffin.

The protein in eggs can help boost your immune system and help improve recovery following workouts, thereby reducing fatigue. Protein foods like eggs also can potentially lift your mood since they support the release of feel-good neurotransmitters. And the cholesterol in eggs is beneficial for brain health and the production of important hormones that help regulate many aspects of health.

2. Fish — As one of the healthiest sources of lean protein that is available to us, most types of fish are full of amino acids and healthy fats, including omega-3s, B vitamins, iron and more. B vitamins in fish (plus meat, eggs and other protein foods) are needed to convert food into energy.

Omega-3s in fish have been linked to cognitive health and even improved focus. Some of the best types to eat regularly? Wild-caught sardines, salmon, tuna and mackerel should be at the top of your list.

3. Chicken or beef liver (and other organ meats) — Hands down, liver is one of the best sources of nutrients, including vitamin B12, iron and the active form of vitamin A (not found in plants), all of which keep your mind sharp.

You’ll also get protein, riboflavin, copper and other B vitamins from liver, all of which are important for metabolic health and energy production. Iron in particular is needed for muscle function, brain function and hemoglobin formation (a red protein responsible for transporting oxygen in the blood).

You may not love the idea of eating organ meats, but keep in mind that even small portions provide a high amount of nutrition. You can try mixing ground liver with ground beef, turkey or chicken (such as in meatballs or meatloaf) to make the taste more appealing.

4. Dark chocolate (cocoa) — There’s a reason we crave chocolate when we’re feeling sad and fatigued. It’s been shown to improve mood and brain function, not to mention potentially reduce pain and boost circulation.

Real dark cocoa contains some caffeine, although less than coffee, plus antioxidants, including flavonoids that have various health-promoting effects. Cocoa may be especially helpful for women during fatigue-inducing points in their menstrual cycle. Opt for a minimally processed dark chocolate with at least 70 percent of cocoa for the most effects.

5. Nuts and seeds — Another healthy source of fatty acids and fiber, nuts and seeds are nutrition powerhouses that pack an impressive punch, even when eaten in small quantities.

Walnuts are a great source of alpha-linolenic acid and vitamin E, which has been liked to mental/cognitive health benefits. Almonds, flaxseeds and chia seeds are other great sources of nutrients, including calcium, iron, zinc and B vitamins.

6. 100 percent whole grains (like quinoa or oatmeal) — These complex carbs provide you with slow-absorbing glucose that your brain and muscles guzzle up for energy.

Thanks to their high fiber content, they also help keep you full for longer, meaning your blood sugar and mood won’t plummet shortly after finishing eating. A winning combination of whole grains, protein and healthy fats is ideal for building a reserve of energy that your body can draw on throughout the day.

What types of food and drinks should you avoid because of their tendency to rob you of energy?

The biggest offenders include alcohol, sugary drinks (soda, juice and even many smoothies), products made with refined grains like pastries, candy and heavily processed or fried foods. Many of these release a surge of sugar into your bloodstream quickly, spiking your energy but setting you up for a crash later on that leaves you tired and hungry.

The biggest offenders include alcohol, sugary drinks (soda, juice and even many smoothies), products made with refined grains like pastries, candy and heavily processed or fried foods. Many of these release a surge of sugar into your bloodstream quickly, spiking your energy but setting you up for a crash later on that leaves you tired and hungry.

If you are going to indulge and eat sweets or other “comfort foods,” try to strike a balance by combining a source of carbs, protein and fat, which should keep you alert and full for longer.