And understanding the role of genes in our eating habits and food preferences could lead to personalised diets that are easier to follow, according to researchers.
They say gene variants that affect the way our brain works may be the reason people keep eating certain foods - even if they know they’re not good for them.
Silvia Berciano, a predoctoral fellow at the Universidad Autonoma de Madrid in Spain, said: “Most people have a hard time modifying their dietary habits, even if they know it is in their best interest.
“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.”
Although previous research has identified genes involved with behaviour seen in eating disorders such as anorexia or bulimia, little is known about how natural variation in these genes could affect eating habits in healthy people.
Mr Berciano said gene variation is a result of subtle DNA differences among individuals that make each person unique.
For the new study, the researchers analysed the genetics of 818 men and women of European ancestry and gathered information about their diet using a questionnaire.
The researchers found that the genes they studied did play a “significant” role in a person’s food choices and dietary habits. For example, higher chocolate intake and a larger waist size was associated with certain forms of the oxytocin receptor gene, and an obesity-associated gene played a role in vegetable and fibre intake.
They also found that certain genes were involved in salt and fat intake.
Mr Berciano said the new findings could be used to inform precision-medicine approaches that help minimise a person’s risk for common diseases such as diabetes, heart disease and cancer--by tailoring diet-based prevention and therapy to the specific needs of an individual.
He added: “The knowledge gained through our study will pave the way to better understanding of eating behaviour and facilitate the design of personalised dietary advice that will be more amenable to the individual, resulting in better compliance and more successful outcomes.”
The researchers plan to perform similar investigations in other groups of people with different characteristics and ethnic groups.
They also want to investigate whether the identified genetic variants associated with eating are linked to increased risks for disease or health problems.
Mr Berciano was due to present the findings at the American Society for Nutrition Scientific Sessions in Chicago.