Sweet Tooth

Your result, the one DNA position behind it, and what the research says.

9/10 confidence.

About Sweet Tooth

FGF21 is a hormone released mainly by the liver that acts on the brain to influence what you feel like eating, and it appears to act as a brake on sugar and sweet foods specifically rather than on appetite in general. This variant is associated with a modest shift in that signal. The finding has replicated across several large studies, but the differences are averages across many thousands of people and are small next to habit, availability and everything else that shapes what you eat.

Good to know: FGF21 appears to act on sweet foods specifically, not on appetite generally. The measured differences are small averages across large groups. Habit and availability shape sugar intake far more than this position.

Fun fact: FGF21 is one of the few hormones known to influence a taste preference rather than hunger itself.

Discovery: This position was linked to the share of daily energy taken as carbohydrate and protein in 2013, and to sweet preference in later work.

The Variant

The single variant behind this trait

Gene: FGF21

Variant (rsID): rs838133

Location: Chr 19:48,756,272

dbSNP rs838133

The studies

Novel locus including FGF21 is associated with dietary macronutrient intake (Chu AY et al., Human molecular genetics, 2013)

Single Nucleotide Polymorphisms in Close Proximity to the Fibroblast Growth Factor 21 (FGF21) Gene Found to Be Associated with Sugar Intake in a Swedish Population (Janzi S et al., Nutrients, 2021)

Higher fasting plasma FGF21 concentration is associated with lower ad libitum soda consumption in humans (Basolo A et al., The American journal of clinical nutrition, 2021)

Other lifestyle traits

Fullness Signaling: A marker near the leptin gene, which produces the hormone fat tissue uses to tell the brain how much energy is stored.

Coffee Intake: A change near the gene for the receptor that switches on caffeine-clearing enzymes, tied to how much coffee people actually drink.

Fresh Fruit Preference: A change near a transcription factor, linked in a very large survey to how much fresh fruit people report eating.

Back to All Traits

Content updated September 2026.

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