Step away from the sodas and energy drinks. There are healthy snacks that can give you an energy boost when you need one -- without all the sugar.

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When mid-afternoon sluggishness strikes, what do you reach for? A snack from the office vending machine? Maybe an energy drink? While they may give you a quick jolt of energy to make it through the remaining afternoon, beware of both.

A typical vending machine snack is going to score low in nutrition and high in calories and fat, including unhealthy saturated fats. Let's take a pack of frosted strawberry Pop-Tarts as an example: Those two pop-tarts have more than 400 calories combined, more than enough for two snack attacks, 10 grams of fat (including bad fats) and about 9.5 teaspoons of sugar [source: Sole-Smith]. And those energy drinks? You're looking at as many as 13 teaspoons of sugar in one 16-ounce can, and the caffeine equivalent of at least four servings of cola [source: Brody].

Instead of feeding your fatigue with unhealthy, empty calories, try fine-tuning your diet to keep fatigue at bay.

While most of us are able to get our essential vitamins and minerals from the foods we eat -- although maybe that perfect balanced diet of lean protein, healthy carbs and fresh fruits and vegetables is aspirational for many of us -- there are a few things that might cause a deficiency, from autoimmune diseases to certain types of anemia and other malabsorption problems (and as you've probably heard, that habit of skipping breakfast isn't helping). Symptoms of a deficiency vary depending upon what vitamin is lacking. For example, a severe deficiency in vitamin C causes scurvy. Deficient in vitamin D? You're at risk for rickets. A deficiency in B vitamins may zap your energy and cause mood changes -- everything from feeling tired, weak, light-headed, irritable, anxious, depressed and in a mental fog (among other problems).

Let's crack open those B vitamins, next.