Soon after lunch, people experience afternoon slump. Citrus fruits or dark chocolates can help you in being more productive at work.

Chips from the vending machine or cookies your co-worker baked are not what your brain needs. Huffingtonpost.com suggests a list of food items to keep you alert: 

- Dark chocolate: When you eat dark chocolate, compounds in cocoa called flavanols produce a surge in blood flow to the brain. That helps you feel awake and alert.

- Citrus fruits: Just sniffing them can stimulate alertness. Eat an orange, and you also benefit from vitamin C.

- Water: Just about every system in the body suffers when we're dehydrated, including the brain. So, keep a reusable bottle or cup on your desk to remind you to drink.

- Coffee or tea: Caffeine keeps you alert and also boosts cognitive performance, concentration and focus.