Researchers say new information about the genetic links behind food intake, obesity, and diabetes could lead to improved prevention and treatment.
In the largest ever study to examine how genetic factors affect a person’s food choices and consumption, researchers have identified more than two dozen regions of genetic sequences that may affect individuals’ food intake.
“The average daily intake of nutrients and foods, a major contributor of obesity, is partly influenced by our genetics,” says Chloé Sarnowski, who was a biostatistician at Boston University while conducting the study and is now a faculty associate at the University of Texas Health Science Center at Houston. Sarnowski is co-lead author of the study in the journal Nature Human Behaviour.
Researchers say the brain is influenced by various signals that affect people’s eating behaviors and regulate their bodies’ energy balance. Those signals, for example, control appetite and energy expenditure in response to blood levels of key metabolic hormones and nutrients. Genetic variation in these signals can therefore lead to extreme hunger—and obesity.
“Despite the high correlation between [genetics and] our dietary choices, a limited number of genetic studies have integrated information about [preferences for] different nutrients or foods,” Sarnowski says.
“We jointly analyzed the main nutrients that the body needs and uses in large amounts—carbohydrate, protein, and fat—to better characterize the genetic regions that influence our dietary choices.”
For the study, Sarnowski and collaborators analyzed the genes and examined the food consumption of 282,271 participants of European ancestry from the UK Biobank and the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium.
From that data, the team identified 26 genetic regions associated with increased preference for foods containing more fat, protein, or carbohydrate. In the brain, those genes influence specialized areas of brain cells, distributed across the central nervous system, that are responsive to proteins, fats, or carbohydrates.
“When [those areas of the brain are] activated, [it] may explain why people are more likely to prefer foods or meals with higher amount of fat, protein, or carbohydrate,” says coauthor Jordi Merino, a research associate at the Massachusetts General Hospital Diabetes Unit and Center for Genomic Medicine and a Harvard Medical School instructor.
The discovery of these genetic variants could be used in future research to determine whether diet composition is causally related to type 2 diabetes, obesity, and other diseases.
“While we know that diet composition is related to diseases, the causal link is harder to prove,” says co-senior author Josée Dupuis, chair and professor in Boston University’s School of Public Health’s biostatistics department.
The findings underscore why food consumption behavior differs among individuals.
“Our results could also help identify people more likely to follow specific dietary recommendations for the prevention of obesity or diabetes,” says coauthor Hassan Dashti, a Massachusetts General Hospital instructor of anesthesia, critical care, and pain medicine and a Harvard University associate professor of anesthesia.
“For example, if someone has a higher genetic susceptibility for preferring fatty foods, this information can be used to help this individual to choose foods with higher amounts of healthy fats rather than recommending other dietary approaches that might compromise adherence to these interventions.”
The American Diabetes Association, the European Commission Horizon 2020 programme, the National Institutes of Health, the MGH Research Scholar Fund, the Novo Nordisk Foundation, and the Lundbeck Foundation funded the work.
Source: Boston University