Are you regularly confronted by yearnings for potato chips and ice cream? Or are your cravings more of the bizarre, specific variety—dried fruit, soda, or dark chocolate? Ever wonder why you crave what you crave?

Cravings typically come in two varieties: They’re either born out of habit, or out of nutrient or other biochemical deficiency. So how do you know which is responsible for your late-night longings? Although it would be hard to tell without a full blood chemistry analysis, there are a few ways to know what’s behind your craving.

Let’s break our cravings down into three categories: Salty, sweet and specific foods.

Cravings for salty foods can indicate a sodium deficiency, and unless you suffer from high blood pressure, it may be valuable to find ways to slightly increase your sodium intake. We don’t, however, recommend doing this by gorging on potato chips, but rather by adding a sprinkle of pure sea salt to a bowl of veggies.

Cravings for sweet foods may actually be your body and mind’s longing for a hit of the feel-good hormone serotonin, which is activated when you consume carbohydrates. Yet there are a number of ways to tap into a carbohydrate high that doesn’t involve binging on donuts. Fruits, vegetables and whole grains all contain healthy doses of carbohydrates that will feed your brain and fuel your body.

Cravings for specific foods like chocolate or carbonated drinks may indicate low levels of nutrients like magnesium, copper and iron (in the case of chocolate), or calcium (in the case of carbonated drinks). The best way to address these cravings is to find beneficial sources of the nutrients in demand. Magnesium can be found in nuts and seeds, and calcium in leafy green vegetables. You’ve always got the power to choose—and making small choices for the better can help you shift the bad food habits you’ve built up over time.

And remember, what matters more than the craving itself is how you fulfill it!