The Science Behind Your Sugar Cravings, According to Experts

Sometimes (or, um, many times), your body decides it wants a bag of Sour Patch Kids or a chocolate bar, stat. Whether they hit every day or once in a while, sugar cravings are simply a fact of life. But the intensity with which they can pop up makes us wonder: Where do they even come from and what can they tell you about your body?

The science surrounding sugar cravings can actually be pretty complicated. That’s because they typically don’t have one single, easily identifiable cause. Rather, tons of different factors can influence when, where, and why you might develop a sudden hankering for a little treat, including your biology, psychology, and environment, Lindsay Malone, MS, RDN, LD, a nutrition instructor at the Case Western Reserve University School of Medicine, tells SELF. What’s more, Malone notes, these factors often overlap and intersect, complicating matters further. But don’t worry; we’ll break it down for you. Read on for everything you need to know about the four big elements that may be behind your confectionery cravings.

Your blood sugar (and all its ups and downs) might be involved.

In fact, fluctuations in blood sugar are “one of the biggest” contributors to sugar cravings, according to Malone. “Your blood sugar is your body’s primary fuel source,” she says, so your body closely monitors your levels to make sure you have the energy to function normally. When they drop, alarm bells start ringing, nudging you to take action to return to baseline. The fastest, easiest fix for a plunge: Getting a dose of sugar from a food or beverage—which is why you might find yourself reaching for a super-sweet item “like juice, candy, or soda,” Malone says. “Sugar is a carbohydrate, and carbohydrates are a very accessible and digestible source of energy,” Vincci Tsui, RD, a certified intuitive eating counselor based in Canada, tells SELF.

While your blood sugar can fluctuate naturally throughout the day, certain triggers can cause it to rise and fall rapidly, bringing about these sugar cravings. Dieting or otherwise limiting your food intake is one example. “Having a sweet craving can be a way of our bodies telling us, ‘Hey, we’re not eating enough’”—a.k.a. taking in enough fuel, Tsui says. Sugar cravings can also be a response to the specific type of food you’re eating, rather than the amount. For example, Malone says, simple carbohydrates (including sugars) cause an immediate blood sugar spike followed by a steep drop, setting those alarm bells off. Yes, they’ll raise your blood sugar and improve your energy in the short term—great for an acute plunge like we mentioned above—but they’ll ultimately only create a vicious cycle that’ll leave you right back where you started. That’s why your meals and snacks should represent a balance of all three macros: carbs as well as protein and fats. “That would result in a much more steady, stable blood sugar where you wouldn’t have this kind of up and down,” Malone says.

What and how much you eat aren’t the only factors that affect blood sugar fluctuations, however, according to Malone. Genetic differences, menstruation, sleep quality, certain health conditions like diabetes or hormonal imbalances, and lifestyle factors (say, chronic stress or limited physical activity) may play a role as well, to name a few others.

But your environment can come into play, too…

Habit and custom can be powerful forces, so you can inadvertently train your body to expect sweet foods under certain circumstances. In this case, your sugar cravings are the result of “a routine that gets ingrained,” Malone explains.

If you always swing by a Starbucks drive-thru to pick up a mocha latte on your way to work, you might start to experience sugar cravings in the morning. If you always eat dessert after dinner, they might pop up after you finish your evening meal. Finally, if you always have eggnog or cutout cookies at Christmas, they could pay a holiday visit after you glitz your tree out.

Basically, your body learns to associate specific locations, times, and occasions with a sugar hit, according to Malone—so as that nears, your body starts to anticipate that sweet treat.

…and don’t discount your emotional state, either.

Many people have strong positive or negative feelings about sugar that can influence their cravings, according to Tsui. Sugar, after all, occupies an unusual niche in the food sphere—simultaneously revered for its enticing taste and demonized for its close ties to “junk food.”

On one hand, some folks think of sweet stuff “as comforting, as being a treat,” Tsui says. In response, they may crave sweet foods for the associated psychological benefits, like a temporary mood boost, when they need that comfort, she says. Sometimes, these cravings can even amount to a form of self-medication—a way to “manage difficult or intense emotions,” Tsui says. (Hence the term “comfort food.”)

On the other end of the spectrum is the widespread perception that sweet foods are “bad” for your health, which can make people try to avoid them and cut them out of their diet completely. But this absence can leave a hole that paradoxically drives that sugar craving as well. After all, we tend to want what we can’t have.

And last but not least, sugar is also just plain palatable, period.

Revelation alert: It’s no coincidence that humans are so drawn to sugar. In fact, we evolved to like it because it signifies “something that can give us energy,” Tsui says—a huge consideration in prehistory, when starvation was a constant threat.

What’s more, this draw is reflected in your brain chemistry. Sugar actually stimulates your brain’s reward system, triggering the release of feel-good chemicals like dopamine (the so-called “happy hormone”) and serotonin (a neurotransmitter that regulates mood and appetite), according to Malone.

Simply put, sugar not only tastes good—naturally appealing to your palate—but it also makes you feel good. “Not only are you enjoying the taste of whatever you’re eating, your brain is really liking it,” too, Malone says. And what do you do when something tastes good, whether it be a Milky Way or a slice of lava cake? “You want more.”

Here’s the bottom line on what to keep in mind when you’re craving something sweet.

While we broke all the buckets down for you, it’s important to keep in mind that sugar cravings actually tend to be triggered by a complex interplay of these factors rather than a single one alone. “Often, I find it’s a combination,” Tsui says.

If you develop a sudden sugar craving after eating lunch in the office, a multitude of different causes could be contributing. Maybe you’re used to ending a meal with a sweet treat. Maybe your blood sugar took a nosedive because your granola bar lunch skimped on protein. Maybe you’re starting to feel sleepy or developing some mental fatigue after grinding away at a task for hours and want some comfort food to make you feel better. Of course, the exact combo will vary on a case-by-case basis, but some type of sudden confluence makes the 2:srcsrc p.m. to 4:srcsrc p.m. window a prime time for sugar cravings, according to Malone.

Sugar cravings in general are a normal and natural experience—a fact of life, really. Without the nutrients (yep, the sugar) provided by the fruit your ancient ancestors ate, you may well not exist. Even babies show a preference for sweet flavors, suggesting an attraction is biologically predisposed, according to Tsui. Too much of anything can be harmful, of course, but experiencing sugar cravings doesn’t mean that you’re “weak” or “self-indulgent” or signify any other kind of character flaw—it’s part of what makes you human.