Do you crave fatty foods or salty snacks? Does the thought of chocolate make you swoon? Or do you—as you know you should—delight in fruits and vegetables? Whatever your food preferences, you are likely aware that they’re not strictly a matter of willpower. For better or worse, your diet is shaped by environmental, cultural, and social factors—and your genetics.
Although people with eating disorders such as anorexia and bulimia have been evaluated for genes that influence dietary behaviors, healthy people have often been overlooked. Consequently, little is known about the natural variations in the behavior-related genes that might affect eating behavior among people who simply hope to stick to healthier diets.
Working to fill in this gap is an international team of scientists that analyzed the genetics of 818 men and women of European ancestry, evaluating single-nucleotide polymorphisms (SNPs) within 38 loci (1359 SNPs) selected on the basis of previous associations with several behavioral and psychological traits (that is, stress, addiction, depression, impulsivity, novelty-seeking, aberrant eating) from genome genotype data. In addition, the scientists gathered information about their diet using a questionnaire.
Ultimately, the scientists found that the genes they studied did play a significant role in a person's food choices and dietary habits.
One team member, Silvia Berciano, a predoctoral fellow at the Universidad Autonoma de Madrid, presented the new findings during the Experimental Biology 2017 meeting, which is still being held in Chicago. The findings also appeared in an article (“Behavior Related Genes, Dietary Preferences and Anthropometric Traits”) that is in the April issue of the FASEB Journal.
“Significant associations were observed for the FTO locus with vegetable and total fiber intake; the CREB1 and GABRA2 loci were associated with salt intake; and the SLC6A2 with total fat and monounsaturated fatty acids,” wrote the article’s authors. “Finally, chocolate intake was associated with variation at the OXTR locus.”
The authors noted that many nominally significant associations were observed between genetic variability at the selected loci and the consumption of specific foods and nutrients, but they emphasized that the most significant association with anthropometric traits was found with certain forms of the oxytocin receptor gene. This gene was not only linked with higher chocolate intake, but also greater waist circumference.
“Our data indicate that genes implicated in behavioral and psychological traits drive a significant component of an individual’s food preferences and dietary habits,” the authors continued. “This information will contribute to a better understanding of eating behavior and facilitate the implementation of personalized dietary advice that should result in better compliance and more successful prevention and therapy of chronic disorders.”
The researchers plan to perform similar investigations in other groups of people with different characteristics and ethnicities to better understand the applicability and potential impact of these findings. They also want to investigate whether the identified genetic variants associated with food intake are linked to increased risks for disease or health problems.
“Most people have a hard time modifying their dietary habits, even if they know it is in their best interest,” said Berciano. “This is because our food preferences and ability to work toward goals or follow plans affect what we eat and our ability to stick with diet changes. Ours is the first study describing how brain genes affect food intake and dietary preferences in a group of healthy people.”
“The knowledge gained through our study,” Berciano asserted, “will pave the way to better understanding of eating behavior and facilitate the design of personalized dietary advice that will be more amenable to the individual, resulting in better compliance and more successful outcomes.”