Slim people have a genetic advantage when it comes to maintaining their weight

In the largest study of its kind to date, Cambridge researchers have looked at why some people manage to stay thin while others gain weight easily. They have found that the genetic dice are loaded in favour of thin people and against those at the obese end of the spectrum.

More than six out of ten grown-ups in the UK are overweight, and one of every four adults is obese. By age five, just about one out of four youngsters are either overweight or obese. Excess weight builds the danger of related medical issues including type 2 diabetes and coronary illness.

While it is notable that adjustments in our condition, for example, easy access to high-calorie foods and sedentary lifestyle, have driven the ascent in heftiness as of late, there is impressive individual variety in load inside a populace that has a similar environment. A few people appear to be ready to eat what they like and stay thin. This has driven a few people to describe overweight individuals as apathetic or lacking determination.

With support from Wellcome and the European Research Council, a team led by Professor Sadaf Farooqi at the Wellcome-MRC Institute of Metabolic Science, University of Cambridge, established the Study Into Lean and Thin Subjects – STILTS – to examine why and how some people find it easier to stay thin than others.

Studies of twins have shown that variation in body weight is largely influenced by our genes. To date, studies have overwhelmingly focused on people who are overweight. Hundreds of genes have been found that increase the chance of a person being overweight and in some people, faulty genes can cause severe obesity from a young age.

Scientists could select 2,000 individuals who were thin (characterized as a weight list (BMI) of under 18 kg/m2) yet strong, with no therapeutic conditions or dietary problems. They worked with general practices over the UK, taking salivation tests to empower DNA investigation and getting some information about their general health and ways of life.

It is believed to be the only cohort of its sort in the world and the scientists state that the UK’s National Institute for Health Research – the National Health Service’s examination foundation – emphatically empowered and upheld their exploration.

Scientists compared the DNA of some 14,000 people –1,622 thin volunteers from the STILTS cohort, 1,985 severely obese people and a further 10,433 normal weight controls.

The team found several common genetic variants already identified as playing a role in obesity. In addition, they found new genetic regions involved in severe obesity and some involved in healthy thinness.

To see what impact these genes had on an individual’s weight, the researchers added up the contribution of the different genetic variants to calculate a genetic risk score.

Dr. Inês Barroso said, “As anticipated, we found that obese people had a higher genetic risk score than normal weight people, which contributes to their risk of being overweight. The genetic dice are loaded against them.”

Professor Sadaf Farooqi said, “This research shows for the first time that healthy thin people are generally thin because they have a lower burden of genes that increase a person’s chances of being overweight and not because they are morally superior, as some people like to suggest. It’s easy to rush to judgment and criticize people for their weight, but the science shows that things are far more complex. We have far less control over our weight than we might wish to think.”

“We already know that people can be thin for different reasons. Some people are just not that interested in food whereas others can eat what they like, but never put on weight. If we can find the genes that prevent them from putting on weight, we may be able to target those genes to find new weight loss strategies and help people who do not have this advantage.”

Three out of four people (74%) in the STILTS cohort had a family history of being thin and healthy and the team found some genetic changes that were significantly more common in thin people, which they say may allow them to pinpoint new genes and biological mechanisms that help people stay thin.

The study published in the journal PLOS Genetics– was funded by the European Research Council and Wellcome.