Do you like steak best, or pasta? – It’s mostly down to your genes

 

Scientists have analysed the eating habits and genetic profiles of 280,000 West Europeans to find out if our genes help to determine whether we prefer protein, carbohydrate or fat.

It’s lunchtime, and the employees go to the canteen.

They’re served a buffet, and there’s plenty to choose from. But instead of taking a little from every plate, bowl and pot, the majority of employees fill their plates in a way that doesn’t change much from day to day:

One group goes straight for the carbs – coarse bread or dishes with a high content of rice and potatoes, often from the vegetarian section of the buffet.

Another group focuses on proteins, especially animal proteins from meat and fish – while a final group prefers a generally high-fat diet.

The question is whether, and if so to what extent, these preferences are innate – i.e. controlled by your genes?

It’s a question that researchers have long wished to answer – not least in the hope of better understanding, and perhaps in time preventing and treating, global obesity, which has now reached such a serious level that 40% of the world’s population can be classified as overweight by clinical criteria, while 13% of the world’s adults live with severe obesity.

An international team of researchers from universities and hospitals in the US, UK and Denmark decided to investigate the issue of food preferences, and have now published their findings in the scientific journal Nature Human Behaviour.

 “And the project produced some interesting new knowledge,” says one of the Danish participants, Tune H. Pers, who is an associate professor and Lundbeck Foundation Fellow at the NNF Centre for Metabolism Research at the University of Copenhagen (KU), and a specialist in the highly complex genetics involved in obesity.

In order to establish possible links between genetics and choice of a diet with an emphasis on either carbohydrates, proteins or fat, the international research team analysed dietary records from 280,000 Western Europeans:

“These included people who had provided information to UK Biobank about their consumption of 200 common foods. The research database also contained the genetic profiles of the people concerned, and by comparing the food preferences of individuals with information from their DNA, a pattern emerged. When these figures were subject to further analysis, it was possible to identify 26 genetic regions that in one way or another help to define a person’s preference for fat, protein or carbohydrates,” says Tune H. Pers.

 

But just how big a role do these areas play?

“You shouldn’t think of it as an on-off switch, because these genetic regions don’t work in such an absolute way at all – but you can measure that they have an influence,” says Tune H. Pers.

“For example, people who have a preference for a high-carb diet will all have a particular kind of activity in a certain set of the 26 genetic regions we were able to identify. But various environmental factors can also influence how these food preferences play out. So the end result – the individual’s choice – will be composed of a mix of the person’s inheritance and environment.”

In 2020, Tune H. Pers, together with two colleagues from the Metabolism Centre at KU, was able to show that 700 genetic variants associated with various aspects of obesity are primarily active in the brain.

“The same is true of the 26 preference regions we have now identified,” he says.

“In the long run, this knowledge could hopefully lead to the development of new medicines and a better understanding of why some people develop severe obesity – but it’s not just around the corner. Before we get to that point, there are a lot of basic biological questions we will need to answer.”

 

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