Fall has arrived. There's a chill in the air, the leaves are beginning to change and the pancreas of every pumpkin spice latte lover is working overtime. It's clear that Starbucks' famous fall beverage is beloved by many, but what happens inside your body after you gulp down that delicious PSL isn't so lovely. In fact, it's pretty gross.

A grande PSL made with 2% milk and topped with whipped cream contains 380 calories, 14 grams of fat and a whopping 50 grams of sugar in just 16 ounces. (That's as much sugar as five Reese's Peanut Butter Cups. Just sayin'.) And all of that sugar has been shown to have a similar effect on the brain as heroin or cocaine.

But it's not just your brain that feels the surge of sugar and fats from your caffeine fix. The rest of your body gets in on the action too. The pancreas works hard to produce insulin to deal with the influx of glucose. Those heightened insulin levels kick the liver into high gear, turning that glucose into glycogen, which is later stored as fat. Triglycerides in your blood increase from all of the fat in that delicious whipped cream. And that fat might manifest itself as, ahem, "gastrointestinal discomfort," dietician and nutritionist Jessica Cording told Yahoo Health. Gross.

What's worse? All of that fat delays the absorption of precious caffeine in your stomach. It could take anywhere from 45 minutes to an hour for the caffeine to kick in. And that's the whole point of a latte in the first place, right?

So next time the urge for a PSL sweeps over you and you find yourself face to face with a Starbucks barista, think of the havoc that heavenly pumpkin spice is wreaking within your body. Then order one anyway, because YOLO. Hey, at least now you know.

Check out the video below for a complete recap of what's going down inside when you drink a PSL: