Our brains, researchers are finding, are like Goldilocks. They tend to be finicky and highly sensitive to the perfect degree and amount.

If there are too few carbohydrates and essential vitamins flowing to our brains, we can't think optimally. Too many of those same nutrients, and our brains go into overload and can't function properly either.  

There's increasing evidence that if we eat just right -- or have the optimal levels of carbohydrates, glucose and fats flowing through our bloodstream -- then thinking is clear, memory improves, and cognitive abilities become considerably stronger.

According to an interesting article at Live Science, it is definitely possible to eat smart. Here are a few tricks to consider before an exam, important presentation, or anytime you want your brain to be as sharp as possible:

• The Hungry Mind: The brain needs fuel, and lots of it. While it's only two percent our total body weight, it devours a whopping 20 percent of our total calorie intake. And it only wants one thing: glucose. Unlike muscle, it doesn't break down proteins for energy. Clear thinking comes down to a steady supply of carbohydrates. And as you may expect, it performs better with healthy, complex carbs, rather than Pop Tarts.

• Maintaining Glucose Levels: Researchers are finding that our brains -- especialy more evolved regions, such as the frontal cortex -- are hyper- sensitive to glucose levels. The ideal amount of glucose in our bloodstream is roughly the amount of sugar found in a banana. When the levels drop below an optimal level, our thinking gets confused and muddy. When levels rise above it, memory loss and cognition are impaired.

• Grazing & High Fiber Foods: Grazing is the best way to eat smarter. That way, we provide our minds with a small, steady supply of energy. The other key is to eat high fiber foods. Snacking on pretzels or sweets sends blood sugar levels soaring. But grazing on raw carrots or other high-fiber foods is likely to help us focus, think clearly and recall information quickly. Another suggestion is to add some fat and protein to limit the spike in blood sugar. Basically, smart food means steady consumption of banana-almond smoothies or carrots dipped in hummus.   

• Good Fats & Fatty Acids: Chances are Einstein avoided bacon cheeseburgers. That's because trans- and saturated fats have proven to slow down our cognitive abilities. Instead, experts suggest sticking with natural sources of unsaturated fats, including cold water fish (such as salmon), seeds and nuts. These also provide Omega-fatty acids, which are thought to be vital for clear thinking.

• Bad Habits: People who skip a lot of meals, chronically undereat or overexercise will be prone to sustained fuzzy thinking. In other words, eating smart means we definitely have to eat.