Halloween Candy and Your Genes: Why Some People Have a Sweeter Tooth
By MyGeneLog™ Team · October 26, 2026 · Pop science
On Halloween night the sweets bowl tells you something about the people around it. Some go straight for it and keep going back. Others take one piece to be polite and forget the rest. Part of that difference is habit and part is what you grew up eating, but part of it, it turns out, is written in your genes.
This is for fun and learning, not diet or health advice. Nothing here can tell you what you should eat, and no genotype decides whether you like sweets.
139 foods, 161,625 people
May-Wilson et al. 2022 asked 161,625 UK Biobank participants how much they liked 139 foods, each on a scale of 1 to 9, and then searched their genomes. Instead of one big "food" taste, the answers sorted into three families: highly palatable foods (the sweet, rich, rewarding ones), acquired tastes (the ones people learn to like over time), and low-calorie foods.
The surprise was how separate the first family was. The genes behind liking sweet, rich food were not the genes behind liking acquired tastes or vegetables; the sweet tooth had a genetic life of its own. Brain scans pointed the same way: each family went with its own, different set of brain measurements.
Liking is more genetic than eating
The study also compared liking a food with actually eating it. The two were closely related, but liking was about twice as heritable as eating. That makes sense: what ends up on your plate depends on price, habit and what is in the kitchen, while how much you enjoy a taste is closer to your own biology.
A gene for the reward, and one for chocolate
A smaller 2023 study of about 2,500 people pointed to RGS9, a gene for signalling inside cells, as a new candidate for liking sweet food; this site has positions near it, such as rs7221051. The authors were careful to say it needs confirming in other studies. The large study found positions in genes such as PAM for liking milky sweets (rs201527548), and one near ADORA2A, the receptor that caffeine blocks, for liking chocolate and coffee (rs57452279), which the caffeine topic follows further.
Where this touches this site
The smell and taste section and the senses topic gather the variants behind how we taste and smell, from bitter vegetables to the smells some people cannot detect. The Gene Knowledge Graph shows each of these genes with everything else it connects to.
So if you are the one guarding the sweets bowl on Halloween, it is not only willpower or the lack of it. Your genes helped decide how good the sweets taste to you in the first place.
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Halloween Candy and Your Genes: Why Some People Have a Sweeter Tooth. MyGeneLog™. https://www.mygenelog.com/updates/halloween-candy-sweet-tooth-genes
Frequently asked questions
Is having a sweet tooth genetic?
Partly. A study of 161,625 people found that liking sweet, rich foods has its own set of genes, separate from the genes behind liking other kinds of food. Habit and what you grew up eating matter too.
Is liking a food more genetic than eating it?
Yes, in that study: how much people liked a food was about twice as heritable as how much of it they ate. What we eat also depends on price, habit and what is in the kitchen.
Which genes are linked to liking sweets?
One small study pointed to RGS9, a gene for signalling inside cells, and the larger study found positions in genes such as PAM for liking milky sweets. Each one shifts liking only a little.
Are these variants on MyGeneLog?
Yes, including rs7221051 near RGS9, rs201527548 in PAM, and rs57452279 near ADORA2A, which turned up for liking chocolate and coffee.
