The other day I was marveling to my husband about how different our daughters' body types and appetites are. Our eldest takes after me with blond hair, green eyes, and a naturally athletic-slash-zaftig shape. She's sensitive, artistic, tidy, big-hearted... and she loves bread more than Oprah does.
Our youngest takes after her dad's side of the family and is long and lithe, with bobbed brunette hair and skinny toes. She's silly, messy, and mischievous and eats more fruit than a bat. She craves protein, too—pulls the cheese out of her sandwiches and throws the bread away. Open a bag of turkey jerky in her vicinity and it's vanishes like a cornfield attacked by locusts.
I've often wondered whether their particular mix of genes—so apparent in their looks and personalities—are also at work in their vastly different tastes in food. I dug into the research and it seems the answer is yes. Earlier this year, Silvia Berciano, a Ph.D. candidate in biochemistry and molecular nutrition at the prestigious Friedman School of Nutrition at Tufts University, along with her colleagues, looked at the diet habits and genetic makeup of 800 American adults. They found that differences in a gene involved in regulating the feel-good hormone oxytocin were related to how much chocolate people ate. Oxytocin is part of the brain's reward system—and the researchers theorized that it's possible that lower levels of the hormone might boost cravings for chocolate in an effort to get that pleasant "reward" feeling.
They also found that a gene known as FTO was linked to veggie and fiber intake, and variations in the hormone-regulating gene SLC6A2 were associated with how much dietary fat people ate. This particular study is preliminary (it was presented at a conference, not published in a peer-reviewed journal yet). But other studies support this link and have found that differences in taste perception—at least in part due to the genetically determined density of taste buds—influence eating choices and caloric intake, too.
A 2000 study in the Journal of the American Dietetic Association found that people with the ability to sense bitter tastes more strongly tend to also like sweet and fatty foods less than others, possibly because they are too intense. On the other hand, so-called "non-tasters" who can't sense as much flavor appear to prefer high-fat foods. Perhaps not surprisingly, being a taster or non-taster has also been linked to waist circumference and BMI.
I can't control my kids' genetically encoded food preferences, and I won't try to. But whether they like it or not (mostly not), I'm going to continue to serve balanced meals with plenty of fruits and vegetables—and enforce the "at-least-one-taste" rule. A recent victory: I made myself a batch of homemade kale chips, and both girls dug in! Apparently crispy texture, plenty of olive oil, and a dash of salt goes a long way, no matter how dense (or not) your tastebuds.
Berciano, S. Experimental Biology 2017. "Could genetics influence what we like to eat?"
Grimm, E. and Steinle, N. Nutrition Reviews 2017. "Genetics of Eating Behavior: Established and Emerging Concepts."
Duffy, V. and Bartoshuk, L. Journal of the American Dietetic Association 2000. "Food acceptance and genetic variation in taste."