There are people who can eat without deprivation of anything, give them pleasure that others live as guilty pleasures and that the body does not show it, while others increase weight with ease. A study by researchers at the University of Cambridge in the United Kingdom showed that in matters of weight, genetics play a role more important than the will.
Overweight and obesity are not aesthetic problem, but health, as they raise the risk of suffering from diabetes, cardiovascular disease and certain types of cancer, among other complications.
Although it is known that changes in our environment, such as easy access to foods that are high in calories and sedentary lifestyles, boosted the increase in obesity in recent years, there is one considerable individual variation In weight within a population that shares the same environment. Some people seem to be able to eat what they like and stay raw, which causes many times to indicate how lazy or unwilling to those who are overweight.
With the support of Wellcome and the European Research Council, a team led by Professor Sadaf Farooqi, at the Institute of Metabolic Science Wellcome-MRC of the University of Cambridge, faced the "Study on Slim and Thin Individuals" ( Stilts) to examine why and how some people find it easier to stay weak than others.
The studies of twins showed that the variation in the body weight is very influenced by our genes. So far, the studies focused enormously on people overweight. From there, hundreds of genes were found that raised the possibilities for a person to be overweight and, in some cases, defective genes can cause serious obesity from childhood.
Professor Farooqi's team recruited 2,000 raw people (defined as a body mass index -IMC- of less than 18 kg / m2) but healthy, with no medical conditions or eating disorders. They worked with general practices throughout the United Kingdom, they took samples of saliva to allow for DNA analysis and asked participants to answer questions about their general health and lifestyles. It is believed that It is the only cohort of its kind in the world and scientists emphasize that the National Institute for Health Research in the United Kingdom, the research infrastructure of the National Health Service, allowed and greatly supported their research.
In the study published in the PLOS Genetics magazine, Professor Farooqi's team collaborated with Dr. Inês Barroso's team at the Institute Wellcome Sanger for compare the DNA of about 14,000 people: 1,622 volunteers from the Stilts group; 1,985 people with severe obesity and 10,433 more normal weight controls.
Our DNA consists of a sequence of molecules known as base pairs, represented by letters A, C, G and T. The strings of these base pairs form genetic regions (which include or form ours nothing). The genes provide the code of how our body works and the changes in the spelling, for example, a C instead of an A, may have Subtle or sometimes dramatic changes in features such as the color of the hair and the color of the eyes, but also on the weight of a person.
Genetic risk score
The team found several common genetic variants already identified by the role they play in obesity. Also, they found New genetic regions involved in severe obesity and some in healthy health. To see what impact these genes had on the weight of an individual, scientists added the contribution of different variants to calculate a genetic risk score.
"We found that obese people had one Genetic risk score higher than people with normal weight, which contributes to their risk of being overweight. The genetic dice are loaded against them", Says Dr. Barroso.
It is important to note that the team also showed that raw people had a much lower genetic risk score; They presented fewer variants that, as we know, raise the possibilities for a person to be overweight.
"This research shows for the first time Thin and healthy people are usually thin because they have a lower burden of genes that increase the chances of a person being overweight and not because they are morally superior, As some people suggest, "says Professor Farooqi. It is easy to hurry to judge and criticize people for their weight, but science shows that things are much more complex. We have much less control over our weight than we might think. "
Three out of four people (74%) in the Stilts cohort presented family history of thin and healthy, And the team found some genetic changes that were significantly more common in thin people, which they say may allow to identify new genes and biological mechanisms that help people to keep thin.
"We already know that people can be thin for different reasons," Farooqi says. Some people simply are not so interested in eating, while others may eat what they like, but they never gain weight. If we can find genes that prevent them from gaining weight, we will be able to address these genes to find new strategies for weight loss and help people who do not have that advantage. "