Research by the UK’s University of Cambridge has concluded that obesity is largely caused by our genes and people have less power over their weight than they like to believe.
The Study Into Lean and Thin Subjects (STILTS) involved 2,000 healthy, thin people (defined as having a BMI of less than 18 kg/m2) with no medical conditions or eating disorders, who were questioned about their health and lifestyles. Saliva samples were also used for DNA analysis and compared with samples from 1,985 severely obese people and 10,433 normal weight controls.
Funded by Wellcome and the European Research Council, the study was led by Professor Sadaf Farooqi at the Wellcome-MRC Institute of Metabolic Science, University of Cambridge, collaborating with a team from Wellcome Sanger Institute, led by Dr Inês Barroso.
Several known genetic variants that play a role in obesity were discovered, as well as new genetic regions involved in severe obesity and some involved in healthy thinness. The researchers added up the contribution of the different genetic variants to calculate a genetic risk score. The thin people had fewer of the genetic variants that are known to increase a person’s chances of being overweight.
Dr Barroso concluded the genetic dice are loaded against obese people: “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.”
“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,” says Professor Farooqi.
“Some people 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.”
Validating and frustrating
Sarah LeBrocq, founder of All About Obesity, says the research is validating and frustrating: “It challenges the narrative that obesity is solely due to lifestyle choices.
“However, it might be disheartening for those who’ve struggled with their weight, as it suggests their efforts may be limited by genetic factors beyond their control.
“It may also raise concerns about how medics interpret this – whether it will lead to more compassion and support, or reinforce a fatalistic attitude.”
LeBrocq advises fitness professionals to use this research as a reminder to shift away from weight-centric approaches and focus on health, strength, mobility and wellbeing.
More: www.hcmmag.com/fatgenes
