At this point, most people understand the basic effects of subsisting on junk food. We’d be hard pressed to find someone who thinks eating a bowl of broccoli is the same as eating a bowl of candy (though doing either will undoubtedly wreak havoc on the human digestive system). But simply knowing that junk food is bad—or even knowing how it’s bad—doesn’t make it any less tempting. Humans have a natural predilection for high-fat, high-sugar foods, and if those ingredients are combined into one magical dish, resistance is practically futile.
Even the healthiest among us have to give in to a cake craving every now and then; it’s normal and won’t do much damage in moderation. The only problem is when we take the craving too far (i.e., eat too much) and end up feeling less than optimal. What happens within our bodies when we eat an excess of sugar that causes such extreme reactions?
This Is Your Body on Cake
When it comes to celebrating, nothing completes the occasion like a rich, perfectly sweet slice of cake. Each bite tastes great going down, but the effects it has on our insides are far less appetizing.
Energy Spike and Crash
We digest cake almost immediately because it’s composed primarily of simple sugars that require little breakdown. Consuming a bunch of them causes a huge rush of glucose (what sugar is broken down to) into the blood, and the pancreas releases extra insulin to turn the glucose into glycogen, which the liver and muscles use up.
After the sugar rush, blood sugar levels drop dramatically, triggering the release of stress hormones like adrenaline and cortisol to activate stored sugar supplies. Stress hormones raise our heart rate, make our stomachs clench in anticipation of an attack, and leave us shaky and nauseated once our bodies realize there’s no danger to respond to.
The amount of sugar in a couple of twelve-ounce sodas might be enough to increase disease susceptibility. That’s according to a study published in the American Journal of Clinical Nutrition, in which researchers found that people’s white blood cell counts were reduced for up to five hours after they ate one hundred grams of sugar.
If there’s any glycogen left over after your liver and muscles become full—and chances are, there will be, unless you were physically active before eating the cake and your raised metabolism can burn through all that sugar—that extra glycogen gets converted into fat. People mistakenly believe that eating fat-free foods prevents weight gain, but since they’re usually supplemented by extra sugar, those foods can be just as fattening.
Impaired Cardiovascular Function
A 2007 study conducted at the University of Calgary and published in the American Society for Nutrition found that eating just one high-fat meal increased blood pressure and made participants’ hearts work harder.
People with Type 2 diabetes must be especially careful when eating cake because of all the sugar, but one study indicates that the butter and oil in the cake might be problematic, too. At the Baycare Centre for Geriatric Care in 2008, researchers tested the memory recall of volunteers with this disease after feeding them fat-filled meals, low-fat meals, or water. Those who ate the heavier meals showed more memory loss afterward than everyone else.
Hurts So Good
Even if we don’t understand the chemical processes taking place inside our bodies after a piece of cake, we do recognize how it makes us feel afterward—not good. Cake is a convenient scapegoat, but most of the processed, packaged foods on the market are loaded with way too much sugar. Our society has one giant sweet tooth that craves supersized soda, king-sized candy bars, and corn syrup by the barrelful. Manufacturers make products like these because there’s a big enough demand for them, though few people would report feeling great after consuming any of them.
Since we know the negative outcomes of eating sugary foods, I wonder what makes us come back for more. Is it that we have selective memory when sugary foods are placed right in front of us? Or is David Kessler, the author of The End of Overeating: Taking Control of the American Appetite, right? He argues that eating junk food causes a surge of pleasure hormones like dopamine and serotonin, so eating poorly actually feels good … at least for a little while.
So our bodies reward and punish us for consuming junk food—no wonder eating right is so confusing! Pinpointing the effects of a sugar overload isn’t always enough to prevent one from happening. After all, knowledge doesn’t make sweets taste any less delicious. However, it might stop a junk food snack from becoming a full-on meal. A little sugar once in a while, especially on special occasions, won’t harm you. Too much at once is when the trouble starts, and clearly, your body will let you know when it’s had enough.