What’s for Dinner: Does your DNA decide?

Written by Amanda Joelle Brown, PhD. Contributions by Eve Freidl, MD.

It’s dinnertime at the Smith household:

Emma, age 10, and Mia, age 7, are sitting across the table from their mom and dad.  Emma is tall for her age, athletic, and very active.  Mia, on the other hand, is small, thin, and prefers reading over playing outside.  Watching them eat, it’s hard to believe they’re siblings.  Emma impulsively scoops a mound of food on her plate, takes one or two bites, and then decides she wants something else.  By the end of the meal, she’s eaten a lot but left even more, and she almost immediately starts nagging her parents to take the family out for ice cream.  Across the table, Mia diligently eats her plateful of plain pasta – her dinner most nights of the week – supplemented by a single piece of broccoli that her mother is working hard to convince her to eat.   Mia perks up at Emma’s request for ice cream (she likes vanilla soft serve even more than pasta), but while Emma’s impatience for the family ice cream run increases with every passing minute, Mia is content to sit and wait, occupying herself with an imaginary game of tic-tac-toe.

How can two girls who share the same parents, the same rules and expectations at home, and maybe even the same bedroom, be so different when it comes to how they think about, choose, and eat food?  At least part of the answer may relate to something they don’t share: half their genes.

It’s common knowledge that genes are largely responsible for whether a person is tall or short, blue-eyed or brown-eyed, blonde or brunette.  The influence of genes on personalities, preferences, and behaviors, however, is less clear-cut.  Here at the Columbia Center for Eating Disorders, we are particularly interested in learning about genetic influences on eating behavior. We think that this information will help us identify possible causes of eating and weight problems that may be good future targets for treatment and prevention efforts.

To that end, we’ve recently started to recruit for a study that aims find connections between eating and eating-related behaviors and a particular gene called FTO, which has been linked to increased body mass in adults in genome-wide association studies.  Rather than recruiting adults with weight problems to study the effects of the FTO gene, we’re aiming a few steps earlier, studying healthy, normal-weight, 5-10 year olds.  This way, we can separate factors that influence the development of weight problems from those that might be consequences of excess body weight.

Previous studies in young children suggest that the FTO gene is associated with choosing to eat higher-calorie foods and eating more in the absence of hunger.  In our “Healthy Kids Study,” we are looking not only at food intake (kids in our current study get to have snacks and a buffet lunch) but also at characteristics like impulsivity and patience. Our kid scientists also participate in MRI scans that will help us identify which parts of the brain are active while they’re playing a food-related computer game.  There are no needles or x-rays involved—just snacks, computer games, a “brain photo shoot” in the MRI, and lunch from a buffet, all in the name of science!

We’ve already started to notice that kids in our study are as different as Emma and Mia when it comes to thinking about, waiting for, and choosing food.  We don’t yet know what that means in terms of the FTO gene, but stay tuned…and in the meantime, if you know any 5-10 year olds who might want to help us learn, have their mom or dad call us at 646-774-8066 and ask about the Healthy Kids Study!

Photo credit (front page): Creative Commons by flattop341

© The Feed, 2013-present. Unauthorized use and/or duplication of this material without express and written permission from this blog’s authors is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to the article’s author and The Feed with appropriate and specific direction to the original content.