The Science Behind: A Sweet Tooth

Isabella Swartz
Aug 15, 2017 · 5 min read

I am part of the 51% of Americans who consider themselves to have a sweet tooth. This lovely little bastard is the reason why I stuff my face with cupcakes, brownies, cookies, candy, and basically any sweet I can when given the opportunity.

Are you hungry yet? (Image Credit: Martha Stewart)

Whether you have a sweet tooth or not is mostly decided by your genetics. Our DNA determines how sensitive we are to certain flavors by deciding what our taste buds will be like. If you have more taste buds for sweetness or your taste buds for sweetness are weak, then you will have a sweet tooth.

Those who have more taste buds for sweetness are attracted to the flavor, and those with weaker taste buds for sweetness need more sugar to get the same hit as someone with normal taste buds (Image Credit: Tenor).

In a study, Dr. Reed and her team tested 243 pairs of identical twins, 452 pairs of non-identical twins, and 511 normal people. Each person tasted and rated the intensity of four different sweet solutions: fructose and glucose — two natural sugars — and aspartame and neohesperidin dihydrochalcone (NHDC) — two artificial sweeteners. They found that genetic factors account for approximately 30% of variation in sweetness from person to person.

NHDC (left) is derived from citrus and aspartame (right) was scienced into being (Image Credit: Wikipedia).

Another factor in deciding the existence and strength of your sweet tooth is your environment. You may prefer sweet foods because you eat them often. This makes these foods familiar and accustoms you to them. Also, growing up with fond memories and emotions surrounding a food — such as your grandma’s cookies — makes you associate that food with those same positive memories and emotions.

However, the opposite is also true. If you eat all of your Halloween candy in one night and throw up, you might hate candy for the rest of your life (Image Credit: Giphy).

Out of all age groups, children are the most vulnerable to having a sweet tooth. It is now believed that kids’ growing bodies prompt them to crave sugar. In a study, researchers from Monell Chemical Senses Center had 108 kids ages 5 to 10 and their moms rate soups, sugar waters, jellies, and crackers with various salt and sugar levels. They found that children who preferred sweet foods over salty ones tended to be tall for their age, and there was no correlation between genetics and a preference for sugar. The kids were hardwired to love sugar.

Kids have stronger cravings for salty foods, as well. In the same study, those who preferred the saltiest foods tended to have more body fat, which would have been useful long ago for times when food was scarce (Image Credit: Boing Boing).

It makes sense that kids love sweet foods. Foods with a higher sugar content supply more energy — making it easier to pursue other food sources — and help store fat. In ancient times, it was much more reliable to hold onto body fat than depend on a rare mammoth. Because of the benefits of having a sweet tooth, those without it wouldn’t have as much energy and create less successful children, if any, preventing the spread of this trait. The human race has trained itself to crave sweets.

That’s right. Sugar used to be helpful (Image Credit: Giphy).

It was a good thing to have a sweet tooth back in ancient times, where you rarely came across something sweeter than a carrot. Back then, weight gain wasn’t much of a risk since carrots aren’t necessarily sugar bombs, but today, we have access to soda, candy, and — even though it pains me to say it — baked goods. The average daily sugar intake in the US is 22 teaspoons, which is four times the amount the World Health Organization suggests.

Moderation is key, my friend (Image Credit: Giphy).

We now face issues like diabetes, obesity, and high blood pressure because of our sweet tooth, despite its good intentions. Sadly, it is impossible to drastically alter your taste preferences, and it would take generations of natural selection to remove the human race’s sweet tooth. The best we can do is work against our cravings and eat healthily.

Works Cited

Davies, Madlen. “Some people really ARE born with a sweet tooth: Genes mean some of us DO need more sugar to get the same hit.” Daily Mail, 15 June 2015, Accessed 9 Aug. 2017.

“51% Say They Have A Sweet Tooth.” Rasmussen Reports, 30 Nov. 2012, Accessed 11 Aug. 2017.

Mackenzie, Macaela. “Why Some People Have a Sweet Tooth and Others Crave Salty Foods.” Women’s Health, Rodale Inc., 19 Oct. 2015, Accessed 9 Aug. 2017.

Roberts-Grey, Gina. “The Science Behind Your Sweet Tooth.” Shape, Meredith, Accessed 9 Aug. 2017.

Singh, Maanvi. “Why A Sweet Tooth May Have Been An Evolutionary Advantage For Kids.” NPR, WHYY, 19 Mar. 2014, Accessed 9 Aug. 2017.

Spector, Dina. “An Evolutionary Explanation for Why We Crave Sugar.” Business Insider, 25 Apr. 2014, Accessed 9 Aug. 2017.

— Isabella S., Pennsylvania


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Show Some STEMpathy

Inspiring scientific literacy, self-efficacy, and student interest in STEM. Run by students from the March for Science: Students for Science

Isabella Swartz

Written by

Show Some STEMpathy

Inspiring scientific literacy, self-efficacy, and student interest in STEM. Run by students from the March for Science: Students for Science

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