Obesity is one of the largest problems facing the United States, and scientists have struggled for years to figure out exactly what causes it. According to a press release from the National Institute of Health, a variation of a gene for brain-derived neurotropic factor, called BDNF, has been found control the levels of a certain protein that influences a person’s appetite. This, researchers believe, could explain the ongoing obesity epidemic in both children and adults.

A study carried out by researchers at the National Institute of Health finds that higher levels of BDNF proteins in the body could help prevent obesity from getting out of control. The study found that this variation was more common in African American and Hispanic patients than it was in non-Hispanic Caucasians.

The study, published in the journal Cell Reports, highlights the fact that obesity is a serious problem in the United States. Obesity makes problems like cardiovascular disease, stroke, and type 2 diabetes even worse, placing strain on the country’s health care systems.

Genes can make a person more likely to become obese, and could determine how successful certain weight loss strategies can be. Cells are the body’s main mechanism for storing energy, and the way genes affect these cells can cause them to store more energy than necessary, which is converted into fat.

The BDNF protein serves multiple purposes in the brain and nervous system. At high levels, the BDNF protein creates the sensation of fullness, letting a person know when they are done eating. When levels of this protein are low, however, people may continue to eat long past the necessary amount. This results in weight being stacked, which can quickly get out of control.

Joan C. Han, an investigator from the NICHD and the University of Tennessee’s Health Center and the lead of the research team that carried out the study, has been researching the BDNF protein and its effects on obesity for quite some time. The researchers analyzed brain tissue samples to single out an area of the gene where one small variation led to a loss of BDNF levels in the hypothalamus, the area in the brain that regulates eating and energy storage.

The genetic variation was not a mutation but a specific difference that is relatively common throughout the general population. Every person has two alleles of a gene, one inherited from each parent. Alleles can vary at any location in a gene, and the researchers called the less common allele, the one that leads to reduced BDNF production, the “C” allele.

The study looked at BDNF genes in four groups of over 31,000 people. They compared the person’s specific BDNF alleles to other factors that affect obesity, like BMI or body fat percentage. They found that African American adults were more likely to have the C allele, which was linked to higher BMI and body fat percentage. The study’s findings suggest that the C allele of the BDNF gene is one of the main drivers of obesity.

According to Dr. Han, the findings could lead to future studies that reveal more about the C allele and the BDNF gene, which could possibly lead to the development of a drug that can help people lose weight.