Flax seeds
Like a few of the foods listed already, flax seeds are high in magnesium, B-vitamins, omega-3 fatty acids, and fiber, all of which aid with mental clarity, weight loss, and ultimately, focus.14 Flax is no doubt a super food. Just make sure you grind them after you buy them (so your body can digest them). Unlike the other items on this list, flax seeds can’t be eaten alone, but they’re great sprinkled on cereal, yogurt, oatmeal, salad, and more.