With National Napping Day upon us, we've been focused on methods to help foster good sleep hygiene and a healthy sleep environment. But what happens after the nap? Diving back into your day after a healthful, restorative nap can be a challenge. And an afternoon caffeine-boost might interfere with later sleep. Instead, we rounded up the most energy-boosting foods out there: snacks that could help you transition back into your day. Or start it -- it's no coincidence that many of these items are frequently found on breakfast tables across America.

Of course, all food is for energy. But that doesn't mean all foods are created equal when it comes to their enhancing powers. Energy-boosting foods are metabolism-boosting foods: Foods that support our bodies' abilities to convert food into energy. B-complex vitamins and omega-3 fatty acids are some of the most energy-boosting nutrients available, but many other nutrients and flavors are associated with increased wakefulness and alertness.

Read on and tell us in the comments, what do you eat to boost your energy levels?

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  • Coffee

    Caffeine and its most popular delivery system, coffee, is an obvious pick-me-up. While we don't recommend drinking it in the late afternoon, <a href="http://www.huffingtonpost.com/2013/02/26/worst-foods-for-sleep_n_2760746.html">when it can interfere with bedtime</a>, a cup of joe can certainly help with alertness and focus. And longterm studies show that java is a good thing for overall health, reducing risk of <a href="http://www.nytimes.com/2009/01/24/health/research/24coffee.html">dementia</a>, <a href="http://www.webmd.com/heart-disease/heart-failure/news/20120626/coffee-in-moderation-may-lower-heart-failure-risk">heart failure</a> and even <a href="http://www.cbsnews.com/8301-204_162-57558820/heavy-coffee-drinkers-shown-to-have-lower-oral-cancer-risk/">some cancers</a>.

  • Dark Chocolate

    We're talking really dark here. If you're eating chocolate for energy, you want the highest cacao concentration possible. That's because cacao has nutrients that <a href="http://www.fitday.com/fitness-articles/nutrition/healthy-eating/the-nutrition-of-cocoa-nibs.html#b">fight stress and boost energy and focus</a>. And dark chocolate has a kick of caffeine, helping to boost energy levels quickly.

  • Citrus Fruit

    Chock full of immune-boosting Vitamin C, these fruits help enhance energy and improve alertness <a href="http://www.marieclaire.com/health-fitness/advice/smell-citrus-lemon-for-energy#slide-7">just from their scent</a>, according to Marie Claire.

  • Water

    We believe in the power of <a href="http://www.huffingtonpost.com/2012/05/07/drinking-water-week-more-water_n_1474999.html">drinking water</a> for many reasons, but energy is chief among them. If you're feeling sluggish, it could be from dehydration, <a href="http://www.mayoclinic.com/health/water/NU00283">which counts fatigue as a common symptom</a>. So a good first step in the fight for greater wakefulness is to drink some H20.

  • Bran Cereal

    Thanks to <a href="http://www.huffingtonpost.ca/2012/08/15/foods-that-boost-energy-_n_1779032.html#slide=1385761">a healthy dose of B-complex vitamins</a> and complex carbohydrates with the sustaining effect of fiber, bran cereal is a food for lasting energy.

  • Salmon

    This <a href="http://www.webmd.com/diet/ss/slideshow-omega-3-health-benefits">oily fish is a powerhouse of omega-3 fatty acids</a>, which are used by the body as building blocks for muscle and other tissues, and for energy.

  • Eggs

    Thanks to their richness in choline, <a href="http://lpi.oregonstate.edu/infocenter/othernuts/choline/">an essential nutrient</a> in the B vitamin family, eggs contribute to energy in several ways: Choline is involved in metabolism and also helps the central nervous system to function.

  • Beans

    <a href="http://www.fitday.com/fitness-articles/nutrition/healthy-eating/the-nutritional-food-value-of-beans.html#b">B vitamin-rich beans</a> also pack a punch when it comes to protein and complex carbohydrates, offering sustained energy throughout the day.

  • Dark Leafy Greens

    Kale, chard, watercress and other nutrient-packed greens help <a href="http://www.webmd.com/food-recipes/features/the-truth-about-kale">promote energy with high levels of brain-boosting</a> Folate, Vitamins C and K and calcium and beta-carotene.

  • Walnuts

    Walnuts have <a href="http://www.tufts.edu/med/nutrition-infection/hiv/health_omega3.html">the most omega-3 concentration</a> of any nut, making them a great energy builder.

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