As the human genome is being explored in more detail, the genetic contribution to obesity is becoming increasingly recognized. While we know of at least 45 genes that contribute to obesity, little is understood about how they work. A new study has discovered a gene that affects how we sense and taste fat in our mouths, and postulates that this gene may be one more mechanism that contributes to the development of obesity in people who are genetically prone.
The study, conducted by MY Pepino and colleagues at Washington University, looked at 21 people with obesity and different variants of a gene called the CD36 gene. They found that people who had two copies of a certain variant of the CD36 gene had an 8 fold lower threshold for sensation of fat than people who had no copies of this gene variant. In other words, people with two copies of the gene variant were far more sensitive to the taste of fat than people without this gene variant.
Exactly how these genetic differences affect food intake is not known. It may be, for example, that people who are less sensitive to the taste of fat need to eat more fat to feel satisfied. Further study is needed to understand how the difference in sensitivity to the taste of fat may affect food intake and body weight.
What is increasingly clear is that genetics have a powerful role in the risk of obesity, in the context of the toxic enviroment in which we live.
Note: you can read more about the genetics of obesity here.