While many people struggle to keep off the pounds, others appear to be able to eat as much as they want and still stay thin.
Now, scientists from the University of British Columbia have discovered a ‘skinny gene’ which could explain why these people don’t gain weight.
Dr Josef Penninger, senior author of the study, said: “We all know these people, who can eat whatever they want, they don’t exercise, but they just don’t gain weight.
"They make up around one per cent of the population.
“We wanted to understand why. Most researchers study obesity and the genetics of obesity. We just turned it around and studied thinness, thereby starting a new field of research.”
In the study, the researchers compared the genetic makeup of 47,102 participants, some of who were thin, and others who were normal weight.
The analysis revealed that the thin participants appeared to have a mutation in a gene called ALK (Anaplastic Lymphoma Kinase).
Dr Michael Orthofer, who led the study, said: “Our work reveals that ALK acts in the brain, where it regulates metabolism by integrating and controlling energy expenditure.”
To test the effect of the ALK gene, the researchers deleted it in files and mice.
The animals were fed the same diet and had the same activity level as mice with the ALK gene, but were found to weigh less and had less body fat.
ALK is highly expressed in the brain, and could be used to develop weight loss drugs, according to the researchers.
D Penninger added: “It’s possible that we could reduce ALK function to see if we did stay skinny.
“ALK inhibitors are used in cancer treatments already, so we know that ALK can be targeted therapeutically.”
