Here are two facts that will come as a news flash to just about no one: first, eating high-fat, high-sugar foods is bad for your body; second, your brain is actually part of your body.

Take these two truths together and it should come as no shock that scoffing pizza and candy does your intellect harm. Nonetheless, most of us tend to worry about how an unhealthy diet will affect our physical health, while ignoring the damage it might do to our thinking.

But according to a fascinating article from Alan Yu for NPR, a growing stack of scientific studies is underlining the fact that your bad diet won't just make you fat and sick, it will also probably make you dumber and more forgetful too.

This is your brain on too much fat and sugar.

The complete piece takes readers on a tour of the latest science, weaving together findings on rats' brains and studies of obese children, as well as research showing that the overweight have less white matter and more inflammation. It's all fascinating stuff if you're looking for a comprehensive review of the field, but the bottom line is crystal clear: mental function, and memory in particular, take a hit when you eat poorly.

If you're obese, you might be "10 to 15 to 20 percent more likely to not quite remember where you put your keys." Lucy Cheke, a psychologist at the University of Cambridge who studies the effects of poor diet on cognition, told Yu.

Of course, not everyone with a love of fast food or candy will see these effects -- the article explains there are ways to compensate for the memory problems caused by a high fat, high sugar diet and notes that research remains ongoing -- but evidence is piling up. The hard truth is you're probably making yourself more forgetful and less sharp if you struggle to keep your hand out of the cookie jar.

That's not exactly a shock to Terry Davidson, another researcher in the field and the director of the Center for Behavioral Neuroscience at American University, who also spoke to Yu. "It's surprising to me that people would question that obesity would have a negative effect on the brain, because it has a negative effect on so many other bodily systems," he said. Why would the brain be spared, he asks.

A short-term issue too

While the long-term effects of chomping away on cakes and chips seem pretty alarming, that's not the only reason you should think twice before routinely indulging. Even if you're a live-for-the-moment type, science shows that high fat, high sugar foods aren't even good for a momentary pick-me-up. In fact, experts insist that unhealthy snacks can cause your blood sugar to peak and crash rapidly, leaving you feeling even more low energy. Instead, try healthy alternatives.