What we eat has a direct impact on our performance at work. Want your mind (and your body) to perform optimally? Then you'll need to practice good nutrition.

While this concept is neither new nor revolutionary, it's the ability to actually do it that's eluding many of us. Why?

One big roadblock is figuring out what "good nutrition" actually means. The amount of conflicting information out there tends to leave us with more questions than answers. Should I be following the food pyramid? Should I do a juice cleanse? Are "heart-healthy" whole grains really heart-healthy? How many Reese's Peanut Butter Cups can I eat before I explode?

When it comes to nourishing our bodies and brains for optimal performance, it turns out good nutrition involves both what we eat and when we eat it. For example, our brains work best with about 25 grams of glucose circulating in our blood stream -- about the amount found in a banana. So snacking on a banana between meals can actually help us sustain our brainpower. If we were to snack on something high in sugar, like a handful of M&Ms, then we risk a blood sugar spike followed by a crash. The result? Low energy and low productivity.

If you're serious about performing your best at work, then making intelligent decisions about food is critical. That's why HubSpot teamed up with EBOC (Entrepreneurs & Business Owners Community) to create an infographic on which foods will help you keep up energy and productivity throughout the day. While you'll certainly have to adapt it to your own dietary needs, think of it as a guide to help you make the right choices to fuel both your body and your mind.