Some people can walk past a plate of cookies without a second thought. Others feel like those cookies are calling their name. Why do our sugar cravings differ so much? The answer isn’t just about willpower. Part of it lies in our DNA, specifically in a gene called GLUT2.
SUGAR AND THE BRAIN
Sugar is a fast source of energy. When you eat it, your body quickly changes it into glucose, the main fuel your cells use. The brain loves glucose. It uses about 20% of your energy, even though it makes up only 2% of your weight.
Because sugar is so strongly tied to energy and reward, humans are wired to prefer sweet tastes. However, the degree of this preference can vary from person to person.
ENTER GLUT2
The GLUT2 gene tells the body how to make a glucose transporter, a gatekeeper that helps move glucose into cells. It helps sense blood sugar levels and sends signals to the brain and pancreas.
A variant of the GLUT2 gene is associated with a greater preference for sugar. People with this version may be more drawn to sweets, more likely to consume sugary foods, and even have a higher daily sugar intake compared to those without the variant.
WHAT STUDIES SHOW
- Individuals with a certain GLUT2 variant tend to report stronger sweet cravings.
- They may eat more sugar overall, even without realising it.
- This genetic influence doesn’t doom anyone to sugar addiction, but it does help explain why some people find moderation harder than others.
WHY IT MATTERS
- Health risks: Eating too much sugar can lead to weight gain, diabetes, and heart disease. If your genes predispose you to crave sweets, watching your diet is even more crucial.
- Self-awareness: Recognising that you may have a biological tendency toward a preference for sugar can help you approach it with strategy, rather than guilt.
- Personalised nutrition: In the future, genetic insights like this could guide dietary advice that’s tailored to your unique biology.
Your sweet tooth isn’t just about habits or lack of discipline. The GLUT2 gene can shape how much you crave sugar and how your body responds to it. While you can’t change your genes, you can manage your choices by swapping out sugary snacks for fruit, balancing meals with protein and fibre, and being mindful of hidden sugars in processed foods.
So next time you wonder why dessert feels irresistible, remember: it might be in your DNA.
References:
Eny KM et al., 2008. Genetic variant in the glucose transporter type 2 is associated with higher intakes of sugars in two distinct populations. Physiol Genomics.;33(3):355-60.
Kulkarni GV et al., 2013. Association of GLUT2 and TAS1R2 genotypes with risk for dental caries. Caries Research. 47:219-25