Halloween candy is difficult to resist, and you might assume that sugar is the sole reason for that. Sugar can activate reward circuits in the brain that also respond to drugs like cocaine. It is possible to build up a tolerance to and dependence on sugar. Studies have shown that sweet or fatty foods can activate pathways in the brain associated with pleasure and reward, kicking off processes that can compete with or override signals that regulate normal hunger and satiety. This sometimes causes people to overeat out of pleasure, not hunger.

How your body handles sugar

While salt, sugar, and fat are all tasty on their own, food scientists have long known they become irresistible when they come together. It’s the convergence of sugar, fat, and salt—the specific combination in many candies, Halloween and otherwise—that really activates the for pleasure eating system. When you taste a sweet food, it releases dopamine into your system. Dopamine plays a major role in the motivational component of reward-motivated behavior—and the effect on your mood is very real.

This effect can occur because you have a memory of previously experienced pleasure. Humans have complex neurologic systems where learning, memory, and pleasure somewhat congeal. Any food can spur this effect, but when you link the nostalgia and positive memories attached to Halloween candy, it’s likely to trigger an intense reaction. It can be difficult to outsmart these bodily mechanisms, though some research suggests that consistently choosing healthful foods can eventually rewire your brain to prefer them.

Your body goes to work on ingesting all that sugar and syrup it as soon as it can. Your stomach breaks down the candy and absorbs it all immediately, which causes your blood glucose to spike. As is the case with salt, too much sugar can cause water retention. As water is absorbed into your blood, your body starts to think that it’s dehydrated. You’ll feel really thirsty as a result.

The hormonal effects of eating sugar

An overlooked organ, you might not know what your pancreas even does. The pancreas is responsible for releasing insulin, which regulates blood sugar. Repeatedly overloading your blood with glucose will overtax the release of insulin. This degradation of the natural response to sugar is a risk factor for diabetes. The spike in blood sugar wreaks havoc on all kinds of hormones, including cortisol and epinephrine. Both of these hormones can send your heart racing in response.

Those hormones do more than just speed up your heart rate. Spiking your blood sugar alters the ratio of estrogen to progesterone in the body. Progesterone calms you down, while estrogen has a tendency to increase the intensity of your emotions.

Digesting all of those simple sugars and chemicals at once wasn’t easy, and natural byproduct of digestion is gas but excess gas causes bloating. General discomfort, indigestion, and flatulence are also probable side effects.

The inevitable drop in your blood glucose is bound to make you feel hungry, despite how much you’ve already eaten. You might feel sluggish, lethargic, or irritable in the process — all of which, in turn, can make you crave more candy.

Normally, when you eat a large number of calories of nutritious food, your body acknowledges those extra calories and naturally consumes less later on. When you consume sugary foods your body is still hungry for those calories later. Your body will still want the protein, vitamins, and minerals it needs.

Conclusion

The worst kind of Halloween candy is any made of pure sugar, like Skittles, Pixy Stix, Airheads, and candy corn. You might think those are less damaging options, since many are marketed as fat free, but these concentrated sweets have a dramatic effect on raising blood sugar, which over time can lead to weight gain, insulin resistance, and diabetes.

When you do have to give into temptation and give yourself a treat, try dark chocolate candy with nuts. These options at least have minor amounts of protein and antioxidants. In general, you should choose candies that contain some actual food, like chocolate, nuts, and coconut.